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SpaceX Vehicles and Missions => SpaceX Early Days Archive Section => Topic started by: Chris Bergin on 05/27/2014 10:11 pm

Title: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/27/2014 10:11 pm
Here we go folks!

Now converted to discussion, party thread, based on the excitement. Link to the actual event update thread shortly.

***MEDIA ADVISORY***

SpaceX CEO & Chief Designer Elon Musk to Unveil Dragon V2 Spacecraft

WHO:                    Elon Musk, CEO & Chief Designer, SpaceX

WHAT:                  Mr. Musk will introduce SpaceX’s new Dragon V2 spacecraft, a next generation spacecraft designed to carry astronauts into space.

WHERE:                SpaceX, 1 Rocket Road, Hawthorne, CA, 90250.

WHEN:                 Thursday, May 29. Check in begins at 6:00 p.m. PT; event begins at 7:00 p.m. PT.

Due to International Trade and Arms Regulations, this event is open to U.S. Citizens and Green Card holders only.  (Funny, as the title of the e-mail was "You're invited!" Boooooo! Not that I can afford the flight ;D)

For those who cannot attend in person, this event will also be webcast LIVE at www.spacex.com/webcast.

While I'm here. Here's our collection of recent Dragon articles:
http://www.nasaspaceflight.com/tag/dragon/

Remember, we have lots of Dragon threads on here. Best to keep this one as clear as possible until the event.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mongo62 on 05/27/2014 10:26 pm
Due to International Trade and Arms Regulations, this event is open to U.S. Citizens and Green Card holders only.  (Funny, as the title of the e-mail was "You're invited!" Boooooo! Not that I can afford the flight ;D)

For those who cannot attend in person, this event will also be webcast LIVE at www.spacex.com/webcast.

Is there a reason why, given that the event will be webcast (presumably worldwide), physical attendance is limited to US citizens and Green Card holders? This does not make a lot of sense to me.

I can only assume that some information will be restricted to the attendants, and will not be webcast.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sublimemarsupial on 05/27/2014 10:30 pm
Due to International Trade and Arms Regulations, this event is open to U.S. Citizens and Green Card holders only.  (Funny, as the title of the e-mail was "You're invited!" Boooooo! Not that I can afford the flight ;D)

For those who cannot attend in person, this event will also be webcast LIVE at www.spacex.com/webcast.

Is there a reason why, given that the event will be webcast (presumably worldwide), physical attendance is limited to US citizens and Green Card holders? This does not make a lot of sense to me.

I can only assume that some information will be restricted to the attendants, and will not be webcast.

Probably facility restrictions since it is at the main Hawthorne site, which as I understand you pretty much have to be a US citizen or green card holder to enter.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/27/2014 10:33 pm

Probably facility restrictions since it is at the main Hawthorne site, which as I understand you pretty much have to be a US citizen or green card holder to enter.

Don't think so. They've invited me over knowing I'm English and I know there's some non US people been toured around the place. Some of them are members here.

Anyway, their call. It's webcast, that's all I care about! :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: braddock on 05/27/2014 10:37 pm
Any idea what the circular encoding around the dragon logo repesents?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 05/27/2014 10:42 pm
Here we go folks!

***MEDIA ADVISORY***

SpaceX CEO & Chief Designer Elon Musk to Unveil Dragon V2 Spacecraft

WHO:                    Elon Musk, CEO & Chief Designer, SpaceX

WHAT:                  Mr. Musk will introduce SpaceX’s new Dragon V2 spacecraft, a next generation spacecraft designed to carry astronauts into space.

WHERE:                SpaceX, 1 Rocket Road, Hawthorne, CA, 90250.

WHEN:                 Thursday, May 29. Check in begins at 6:00 p.m. PT; event begins at 7:00 p.m. PT.



Can you imagine another government contractor doing this?

I suspect Elon Musk is going to do this Tesla style like he did with the Model X reveal.

Watch this video if you want an idea of how his crew does things when they put on a show.

https://www.youtube.com/watch?v=mURbzh9t0_0&feature=kp
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Bubbinski on 05/27/2014 11:14 pm
Maybe the code around the logo is Morse code? Not sure, and I'm afraid I don't know Morse code. Anyway I'll be tuned in!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/27/2014 11:24 pm
Yawn.<< That'll be me on the following morning, since this is a 3AM start for us Brits.

No effect on Chris, of course, since he never sleeps anyway.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RonM on 05/27/2014 11:41 pm
Can you imagine another government contractor doing this?

I suspect Elon Musk is going to do this Tesla style like he did with the Model X reveal.

Since Elon Musk's background is from Silicon Valley style business (PayPal), that kind of showmanship is expected.

Maybe he will emulate Tony Stark from the Iron Man movies and they'll have showgirls doing a dance number.  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Prober on 05/27/2014 11:43 pm

Probably facility restrictions since it is at the main Hawthorne site, which as I understand you pretty much have to be a US citizen or green card holder to enter.

Don't think so. They've invited me over knowing I'm English and I know there's some non US people been toured around the place. Some of them are members here.

Anyway, their call. It's webcast, that's all I care about! :)

its not a news conference as that might start in the morning.

Thursday, May 29. Check in begins at 6:00 p.m. PT; event begins at 7:00 p.m. PT.   

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jcc on 05/27/2014 11:48 pm
Maybe the code around the logo is Morse code? Not sure, and I'm afraid I don't know Morse code. Anyway I'll be tuned in!

Unfortunately not. Not a consistent set of dots and dashes, although a few could be Morse letters. I'm thinking a type of bar code used by a robotic system to identify a tool or object to pick up, and it's orientation. Or it could be somebody's idea of a cool design.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/28/2014 12:00 am
prediction : This thread will be 20 pages long with about -40 decibel signal to noise ratio before the actual event starts. You can do it !
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: nacnud on 05/28/2014 12:08 am
Could the rings around the Dragon logo be a stylised representation of IDSS? Or perhaps a top down view of Dragon 2.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ncb1397 on 05/28/2014 12:22 am
For what it is worth, the ratio of the diameter of the largest circle to the smallest circle is almost exactly the square root of 2.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/28/2014 12:43 am
Is there a reason why, given that the event will be webcast (presumably worldwide), physical attendance is limited to US citizens and Green Card holders? This does not make a lot of sense to me.

You can control where the cameras are pointed, but not the attendees' eyeballs. And if a foreign person's eyeballs land on unclassified technical data subject to ITAR, it's considered an "export" under the law.

ITAR actually stands for International Traffic in Arms Regulations. (http://www.pmddtc.state.gov/regulations_laws/itar.html)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JFARNS on 05/28/2014 12:50 am
Any idea what the circular encoding around the dragon logo repesents?
Could it have to do with this?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IanO on 05/28/2014 01:00 am
Can you imagine another government contractor doing this?

I suspect Elon Musk is going to do this Tesla style like he did with the Model X reveal.

Since Elon Musk's background is from Silicon Valley style business (PayPal), that kind of showmanship is expected.

Maybe he will emulate Tony Stark from the Iron Man movies and they'll have showgirls doing a dance number.  :)
Only if he gets the Rockettes!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: simmy2109 on 05/28/2014 04:19 am
Due to International Trade and Arms Regulations, this event is open to U.S. Citizens and Green Card holders only.  (Funny, as the title of the e-mail was "You're invited!" Boooooo! Not that I can afford the flight ;D)

For those who cannot attend in person, this event will also be webcast LIVE at www.spacex.com/webcast.

Is there a reason why, given that the event will be webcast (presumably worldwide), physical attendance is limited to US citizens and Green Card holders? This does not make a lot of sense to me.

I can only assume that some information will be restricted to the attendants, and will not be webcast.

While SpaceX does give tours to non-US citizens, each individual has to have a background check and other security checks.  This requires advance notice of those attending.  Technically, I don't believe any of the allowed tour areas expose any information that falls under ITAR.  The Dragon unveiling will not be ITAR.  However, freely allowing non-US citizens into your facility filled with ITAR information sounds like a recipe for criminal ITAR violations.

Honestly I don't think SpaceX cares one bit.  They've gone out of their way to get special clearances to hire some non-citizen employees.  But the federal government and their ITAR laws... professors have gone to jail over them.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/28/2014 04:49 am
Confirmed in my email: Livestream will carry the Dragon V2 unveil.

Link.... (http://new.livestream.com/spacex/DragonV2)

Quote
Dragon V2 Unveil

Thursday, May 29th, 2014 at 10:00 PM EDT on spacex

On Thursday, May 29, 2014, SpaceX will reveal Dragon V2 - SpaceX's next generation spacecraft designed to carry astronauts to space. The Unveil will be webcast LIVE beginning at 7:00 p.m. PT.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CuddlyRocket on 05/28/2014 07:59 am
WHEN:                 Thursday, May 29. Check in begins at 6:00 p.m. PT; event begins at 7:00 p.m. PT.

Damn, another late night! Or very early morning - 2100 PT is 0300 BST, if my googling is correct.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/28/2014 08:35 am
WHEN:                 Thursday, May 29. Check in begins at 6:00 p.m. PT; event begins at 7:00 p.m. PT.

Damn, another late night! Or very early morning - 2100 PT is 0300 BST, if my googling is correct.

Yup. See post #8.

That's what popped out when I added 6 PM PT to my calendar.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bilbo on 05/28/2014 07:27 pm
Well, looks like the east is in for a wait  (9:00 PM here)

I'm going to take a crack at trying to see if I can decode these markings. I took a merit badge in Boy scouts that had to deal with Morse code, so I might as well have a go at it. No harm in not trying.

So far my efforts, I have found nothing
 Edit: my attempt at Decoding it
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bubbagret on 05/28/2014 07:47 pm
Time for unveil by time zone:

Los Angeles (U.S.A. - California) Thursday, May 29, 2014 at 7:00:00 PM PDT UTC-7 hours
New York (U.S.A. - New York) Thursday, May 29, 2014 at 10:00:00 PM EDT UTC-4 hours
London (United Kingdom - England) Friday, May 30, 2014 at 3:00:00 AM BST UTC+1 hour
Perth (Australia - Western Australia) Friday, May 30, 2014 at 10:00:00 AM AWST UTC+8 hours
Corresponding UTC (GMT) Friday, May 30, 2014 at 02:00:00     


* fixed day/date.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: aep on 05/28/2014 11:09 pm
Well, looks like the east is in for a wait  (9:00 PM here)

I'm going to take a crack at trying to see if I can decode these markings. I took a merit badge in Boy scouts that had to deal with Morse code, so I might as well have a go at it. No harm in not trying.

So far my efforts, I have found nothing
 Edit: my attempt at Decoding it

I'm also taking a crack at the Dragon Codex. The inside circle has 100 ticks. The second ring has the 2 large arcs both the same length directly opposite, each other and a bit more than a quarter of the circle and 16 small ticks. The outer circle has 12 arcs. I wondered if it's some sort of date indicator but didn't seem to match the list of F1/F9 launches. Here's a marked up image for reference with 0 at the 12 o'clock position.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: padrat on 05/28/2014 11:18 pm
The code contains the detailed outline of Mr Musk's plan for interplanetary colonization and global domination.....



Think "Contact"......










 ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: clongton on 05/28/2014 11:40 pm
Will someone please record and post a link to the webcast?
I will be traveling at the time it begins.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Kabloona on 05/28/2014 11:41 pm

I'm also taking a crack at the Dragon Codex. The inside circle has 100 ticks.

It seems significant that there are only 4 unique segment lengths in the outer ring, and only 2 unique segment lengths in the middle ring.

Outer ring: segment lengths are 1, 5, 9, and 12 units. These appear with a frequency of 2, 8, 1, and 1, respectively.

Middle ring: segment lengths are some fraction of one (1/2?) and 27. These appear with a frequency of  16 and 2, respectively.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 12:01 am
As always, knowing whether there's an answer is half the road to figuring out what it is....
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CJ on 05/29/2014 12:07 am
Hrmmm.. perhaps the plaques on Pioneer 10 and 11 are involved in the Dragon logo?

I'm hesitant to include the image here, because these famous plaques contain line drawings of a nude man and woman, and I'm unsure if this is okay by site rules. I don't see anything specific in the rules against this, so... I'll insert the image, with apologies in advance (plus a request to delete this post) to the mods if I've misinterpreted the rules.

The famous plaque on Pioneer 10 and 11;
http://upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Pioneer10-plaque.jpg/970px-Pioneer10-plaque.jpg

It's the radial lines that the Dragon logo evoked for me, and those radial lines are binary code for the range from the sun to 14 pulsars, using the spin-flip of hydrogen as the base unit.

So, I'm wondering; could the Dragon logo mystery circles be the same sort of binary encoding (circular lines instead of linear)? 
 

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cosmicvoid on 05/29/2014 12:41 am
I'm also taking a crack at the Dragon Codex. The inside circle has 100 ticks. The second ring has the 2 large arcs both the same length directly opposite, each other and a bit more than a quarter of the circle and 16 small ticks. The outer circle has 12 arcs....
It seems peculiar that the inner "clock" ticks don't have a consistant phase with the short segments in the middle ring.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 05/29/2014 12:44 am
You have to think in 3-D.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: BrakeFirst on 05/29/2014 12:53 am
It might be an artist version of a medieval Keep castle?  Where else to house your dragon.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: anderp on 05/29/2014 01:10 am
Due to International Trade and Arms Regulations, this event is open to U.S. Citizens and Green Card holders only.  (Funny, as the title of the e-mail was "You're invited!" Boooooo! Not that I can afford the flight ;D)

For those who cannot attend in person, this event will also be webcast LIVE at www.spacex.com/webcast.

Damn. I happen to be in Los Angeles on holiday for the next week, and I happen to have tomorrow evening free - but I'm Australian! Oh well. Live stream it is.

I couldn't even make friends with an SpX employee to get a tour either :( - ah well. I'm sure I'll be back :)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 01:19 am
I'm also taking a crack at the Dragon Codex. The inside circle has 100 ticks. The second ring has the 2 large arcs both the same length directly opposite, each other and a bit more than a quarter of the circle and 16 small ticks. The outer circle has 12 arcs....
It seems peculiar that the inner "clock" ticks don't have a consistant phase with the short segments in the middle ring.

Yes, that's what I was wondering about as well.  I think it's a tell that there's no message in this bottle.

Regrettably...  Since it is a great tease...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/29/2014 01:22 am
The code contains the detailed outline of Mr Musk's plan for interplanetary colonization and global domination.....

Think "Contact"......

 ;)


You've found the primer?

Clever girl!

(http://4.bp.blogspot.com/-L-CDkN_j8jc/Tv3K3IkMLTI/AAAAAAAAPTY/VWydBhYzHEg/s400/vlcsnap-2011-12-30-07h54m56s200.png)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/29/2014 01:23 am
Ok, last post on this, as fun as it is. As I've mentioned, it's the Dragon as if you were looking straight at it.

Or not...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/29/2014 01:27 am
Hold the phones! I knew I'd seen this thing before!!!!!!!!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/29/2014 01:46 am
Hold the phones! I knew I'd seen this thing before!!!!!!!!

I LIKE it!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lar on 05/29/2014 02:15 am
You'd think this was a party thread or something.

I am torn by two opposing ideas
1) give it to the video decode team
2) sometimes a cigar is just a cigar

I think someone in SpaceX said "make it just enough non random looking that the fan boys go crazy"
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: set321go on 05/29/2014 02:20 am
Not sure what their orbits are but...

logo represents the orbits of earth moon, mars etc in relation to each other or launch/return windows
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/29/2014 05:09 am
Maybe it's alignment markings for an autonomous docking system. The innermost circle is gradians and the other marks make it easier for a little embedded system to calculate the orientation of the circle to the nearest gradian? Like a 2D barcode? Aep's annotated image in the post above should make it easy to sort out if that's the case.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Comga on 05/29/2014 05:47 am
You'd think this was a party thread or something.

I am torn by two opposing ideas
1) give it to the video decode team
2) sometimes a cigar is just a cigar

I think someone in SpaceX said "make it just enough non random looking that the fan boys go crazy"

A blind guy goes to a Passover Seder.
Someone hands him a sheet of matzah.
"Who writes this gibberish?" he asks.

Yeah. This is becoming a party thread.
I have been following SpaceX intently since the middle of 2003.  It appears to be teaching me patience.
One more day....
Wait for it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: go4mars on 05/29/2014 06:00 am
SpaceX operates on metric time.   Of course. 

Easier for colony ops.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/29/2014 11:50 am
What we'll do is convert this into a discussion/party thread for tonight and I'll set up a live update thread ahead of the event.

By the way, we'll need people posting screenshots and updates into the live update thread tonight, as I'll be writing the article.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: obi-wan on 05/29/2014 12:43 pm
Has anybody given any thought as to why Elon is doing this announcement at 7pm locally, which is 10pm EDT? He's too late for the Thursday news cycle in the US or Europe, and so early for Friday that if anything big happens he could get frozen out of the headlines altogether. The only upside I can see is that it lets his fans watch the stream outside of work, but that doesn't seem like a sufficient reason to do it so late. Any thoughts?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChefPat on 05/29/2014 12:58 pm
Has anybody given any thought as to why Elon is doing this announcement at 7pm locally, which is 10pm EDT? He's too late for the Thursday news cycle in the US or Europe, and so early for Friday that if anything big happens he could get frozen out of the headlines altogether. The only upside I can see is that it lets his fans watch the stream outside of work, but that doesn't seem like a sufficient reason to do it so late. Any thoughts?
He's a busy guy & this is when he has time to do it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sghill on 05/29/2014 01:32 pm
Has anybody given any thought as to why Elon is doing this announcement at 7pm locally, which is 10pm EDT? He's too late for the Thursday news cycle in the US or Europe, and so early for Friday that if anything big happens he could get frozen out of the headlines altogether. The only upside I can see is that it lets his fans watch the stream outside of work, but that doesn't seem like a sufficient reason to do it so late. Any thoughts?

As much as we might like otherwise, it's not going to be front page in the morning for anyone but the local news- and space news sites.

This is an evening party after work for invited friends and employees.  Think ice cream social, not 787 rollout.

Plus, as ChefPat said, he's a busy guy.  He's been a fan of these "evening gatherings" and has done them before.  There's a great scene in "Revenge of the Electric Car" where he's close to tears in front of early Tesla buyers at a product development status meeting night.

And that logo looked familiar to me too. It's the combination lock for the Death Star mainframe. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: hayoops on 05/29/2014 02:43 pm
The design around the logo is a typical techy circle interface to convey something is futuristic. It is a very common type of graphic we use to spruce up a presentation. I would guess this representation is more a nod to Iron Man than anything else.

Try a search for "tech circle" and you'll see what I mean.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/29/2014 02:56 pm
Has anybody given any thought as to why Elon is doing this announcement at 7pm locally, which is 10pm EDT? He's too late for the Thursday news cycle in the US or Europe, and so early for Friday that if anything big happens he could get frozen out of the headlines altogether. The only upside I can see is that it lets his fans watch the stream outside of work, but that doesn't seem like a sufficient reason to do it so late. Any thoughts?
In time for the prime time news on the east coast including DC. Also a possible mention on Nightline (newsmagazine on ABC.)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/29/2014 03:24 pm
@obi-wan,

At a guess, he's aiming for a local constituency. Maybe there will be some local business leaders and CA politicians whom he wants to impress first and foremost.

It's unlikely that the national news would be overwhelmingly interested anyway.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/29/2014 04:51 pm
Thread converted into discussion/party thread (don't get carried away however).

New live thread for the event will be on shortly, locked until the event starts.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rifleman on 05/29/2014 05:30 pm
SpaceX just dropped a new teaser for us :)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: WindnWar on 05/29/2014 05:31 pm
If that picture of the seat is real, it looks like it has some very nice looking upholstery at least!  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/29/2014 05:32 pm
Please attach images, not embed them. It breaks the site layout, and horizontal scrolling is an abomination.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rifleman on 05/29/2014 05:33 pm
Please attach images, not embed them. It breaks the site layout, and horizontal scrolling is an abomination.

Sorry, fixed it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Joffan on 05/29/2014 05:34 pm
OK - since we're now officially off update status, I'll speculate that - just as the Teslas drove onto stage, the Dragon 2 will come onto stage from above. Not under rocket power though, I think even Elon can't be that cavalier with the safety of his audience, but perhaps simulated rockets.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rifleman on 05/29/2014 05:36 pm
I will say, I am happy that the seat in the teaser is not blue, its been so overdone lately  8)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/29/2014 05:45 pm
OK - since we're now officially off update status, I'll speculate that - just as the Teslas drove onto stage, the Dragon 2 will come onto stage from above. Not under rocket power though, I think even Elon can't be that cavalier with the safety of his audience, but perhaps simulated rockets.

HA! I just noticed your Avatar! ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Helodriver on 05/29/2014 05:46 pm
So, I'm going to this event. Not sure who I'm going to meet. Any burning questions I should ask if I get the chance to pigeonhole someone?  I'm going at it from a "How does this relate to what's going to happen up at Vandenberg perspective" as in the inflight abort test, because I'm working on an article that is supposed to run in a local paper out of Santa Maria CA. If they are willing to entertain any other SpaceX related topics outside just the Dragon V2 I'll be asking.

Ill try to ask some of the ones you post here if they have time, and I'll post about whatever I wind up seeing on the open side versus L2.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Thunderbird5 on 05/29/2014 05:47 pm
If that picture of the seat is real, it looks like it has some very nice looking upholstery at least!  ;)

So, the 'Signature' leather seats come as standard, I wonder whether Satnav will be an optional extra on this model? Maybe part of the 'LEO Pack'? ☺
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: aero on 05/29/2014 05:53 pm
And it's durable, too. After a few million miles it'll look as good as new! Last longer than any seat ever flown to LEO, reusable of course.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 06:22 pm
I do have a queasy feeling that this will be a Job-esque unveiling event, or the sort of events that they held for Tesla models too.

I don't like those.  Elon comes across best when he just sits down and explains what he has in mind.  Not when they do the personality cult song and dance with warm-up VPs giving tribute and what not.  ugh.

... all of which might serve a purpose with the wider audience, and I can punch through all of it, but we already have enough Richard Bransons in the world.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/29/2014 06:30 pm
I really hope it will not drop to this level

(http://images.smh.com.au/2011/10/20/2717945/art-Branson-Spaceport-3-420x0.jpg)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/29/2014 06:31 pm
this needs a better name

Enter the Dragon
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 06:37 pm
this needs a better name

Enter the Dragon

Any other name would be a miss next to this one.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: banjo on 05/29/2014 06:38 pm
with the down select looming,  a bit of showbiz may not be a bad idea. the more people who think landing on rockets is awesome, the better.    re branson,  elon musk always backs up the show with hardware.    :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 06:53 pm
No, I'm with you.  I think Musk is unique, and SpaceX is the most important endeavor on the planet.

Which is why I like it when Musk gets on a podium, and explains how he's about to move the world - it simply doesn't need the props.

I like it less when it's dumbed down to be "like a new iPod Air" - which needs all the hype and props, because really, it's just mini-micro phoney thing that's got a somewhat larger screen.

And with Musk and SpaceX's track record, to use the Vandenberg CO's words - what this guys says, he does.

But hey - I'm not really complaining.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jabe on 05/29/2014 06:55 pm
SpaceX just dropped a new teaser for us :)


I was surprised to see seats are brown.. for some reason thought it would have the spacex colours..
should be an interesting "show" will have popcorn and beer ready :)
jb
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DigitalMan on 05/29/2014 06:56 pm
So, I'm going to this event. Not sure who I'm going to meet. Any burning questions I should ask if I get the chance to pigeonhole someone?  I'm going at it from a "How does this relate to what's going to happen up at Vandenberg perspective" as in the inflight abort test, because I'm working on an article that is supposed to run in a local paper out of Santa Maria CA. If they are willing to entertain any other SpaceX related topics outside just the Dragon V2 I'll be asking.

Ill try to ask some of the ones you post here if they have time, and I'll post about whatever I wind up seeing on the open side versus L2.

This question comes to mind:  How does this relate to their plans for Mars, considering that they are working on an MCT for that?  Will they build on this vehicle to do any BEO flights?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 05/29/2014 06:56 pm
this needs a better name

Enter the Dragon

Any other name would be a miss next to this one.

Enter The Dragon Theme Music for tonight !!!

https://www.youtube.com/watch?v=HcLD_nLp-bg
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/29/2014 06:58 pm
Yawn.<< That'll be me on the following morning, since this is a 3AM start for us Brits.

No effect on Chris, of course, since he never sleeps anyway.

Cheers, Martin

Yeah... how d'you do it Chris? Caffeine? Modafinil? Have your buddies at the TA simulate gunfire whenever you get drowsy?

Anyway, since you're working on an article, are there any videos in L2 that have the unveiling of manned spacecraft/space-capsules? Be nice to have the photos/a montage.  Is the newest of them all the Shenzhou (considering Dragon hasn't been manned yet)? Did the Chinese have a "grand unveiling"? I'm sure the Shuttle roll-out was an event at NASA - but was it broadcast live or something? I figure Mercury, Gemini, and Apollo LM/CM as well as the Vostok, Voshkod, and Soyuz "unveiling" would've only been internal events, given that they were during the Cold War.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/29/2014 07:17 pm
Yawn.<< That'll be me on the following morning, since this is a 3AM start for us Brits.

No effect on Chris, of course, since he never sleeps anyway.

Cheers, Martin

Yeah... how d'you do it Chris?

I have no choice. The never ending *BING* of my e-mail with report to mod reports of "OMG. That poster just said I was wrong, on the internet!! I'm never wrong on the internet! Ban him, ban him now!!" keep me awake ;)

Live event thread for this all - locked until we get closer to T-0:
http://forum.nasaspaceflight.com/index.php?topic=34841.0
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lobo on 05/29/2014 07:19 pm
SpaceX just dropped a new teaser for us :)

Is that Corinthian leather?

;-)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lobo on 05/29/2014 07:20 pm
this needs a better name

Enter the Dragon

Winner, winner, chicken dinner!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/29/2014 07:21 pm
Quote
If that picture of the seat is real, it looks like it has some very nice looking upholstery at least!  ;)

It's not leather. It's SpleatherX (tm)  8)

Quote
I really hope it will not drop to this level

Could he possibly have any more cheese with that wine?  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/29/2014 07:26 pm
Quote
Which is why I like it when Musk gets on a podium, and explains how he's about to move the world - it simply doesn't need the props.

His best work starts with hands folded.  He gives a quick double nod then says 'ok'..... and the crowd goes silent.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/29/2014 07:29 pm
Quote
Which is why I like it when Musk gets on a podium, and explains how he's about to move the world - it simply doesn't need the props.

His best work starts with hands folded.  He gives a quick double nod then says 'ok'..... and the crowd goes silent.

When he landed on stage at the science expo in the Mark VI suit.. wait I am confusing things.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/29/2014 07:29 pm
I was surprised to see seats are brown.. for some reason thought it would have the spacex colours..
should be an interesting "show" will have popcorn and beer ready :)

Saves some clean-up after the Brown Pants Propulsive Landings.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Orbiter on 05/29/2014 07:32 pm
Rumor has it the unveiling of the Dragon will have a propulsion landing onto the stage with Elon Musk popping out of the hatch to present the Dragon to the world. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/29/2014 07:39 pm
SpaceX just dropped a new teaser for us :)

Is that Corinthian leather?

;-)

You beat me to it! :)  All I could think of when I saw the picture was how Ricardo Montalban used to say that, when he did those ads for Chrysler years ago. "...Rich Corinthian leather!" 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/29/2014 07:42 pm
I was surprised to see seats are brown.. for some reason thought it would have the spacex colours..
should be an interesting "show" will have popcorn and beer ready :)

Saves some clean-up after the Brown Pants Propulsive Landings.

It does appear the CST100 has chosen the blue/purple shades for their capsule's interior.  Therefore the Dragon should be different, and since they worked with Tesla, I might expect, red, brown, black/carbon-fiber.

What would be super cool, is if they have some people inside it with their new spacesuits. Also, the reveal needs lasers and fog machines and space-music.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/29/2014 07:46 pm
How the heck do you get your quotes to show who you are quoting?.......  wait, did I just type that outloud?

Thanks for the replies.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/29/2014 07:49 pm
SpaceX just dropped a new teaser for us :)

Is that Corinthian leather?

;-)

Did you mean Corellian?

(to continue with the star wars theme)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: VatTas on 05/29/2014 07:51 pm
Warm colors should fit Dragon well. After all, dragons are supposed to be hot.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/29/2014 07:52 pm
How the heck do you get your quotes to show who you are quoting?.......  wait, did I just type that outloud?

Like this. :)

I click on "Quote" of the post I wish to reply to, then scroll down to just below the text of their post, which ends in '[ / quote ]'. Then type my text, and click Preview to check it, and Post to post it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Borklund on 05/29/2014 07:55 pm
Another teaser.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/29/2014 07:59 pm
What does DP/DT stand for in the Emergency bracket?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: aero on 05/29/2014 08:00 pm
How the heck do you get your quotes to show who you are quoting?.......  wait, did I just type that outloud?

Like this. :)

I click on "Quote" of the post I wish to reply to, then scroll down to just below the text of their post, which ends in '[ / quote ]'. Then type my text, and click Preview to check it, and Post to post it.

Or, you can click reply to open the window, then scroll down to the post that you want to quote, and click "insert quote" button, like I just did.

And you can do that again and again, if need be.
Another teaser.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: go4mars on 05/29/2014 08:00 pm
What does DP/DT stand for in the Emergency bracket?
Change in pressure over a time increment?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/29/2014 08:02 pm
Another teaser.

"Trunk release"

Also, Fahrenheits, not Celsius. How American.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jdeshetler on 05/29/2014 08:04 pm
Rumor has it the unveiling of the Dragon will have a propulsion landing onto the stage with Elon Musk popping out of the hatch to present the Dragon to the world. :)

with Elon Musk and his six crews popping out of the hatch to present
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: go4mars on 05/29/2014 08:04 pm
Also, Fahrenheits, not Celsius. How American.
That's the beauty of digital guages...  They can speak "rest of the world" too.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/29/2014 08:04 pm
Feels a bit like a chapter from The Rocket Company coming true. John Forsyth revealing DH-1.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/29/2014 08:08 pm
Rumor has it the unveiling of the Dragon will have a propulsion landing onto the stage with Elon Musk popping out of the hatch to present the Dragon to the world. :)

with Elon Musk and his six crews popping out of the hatch to present

And then saying: "We came in peace!" and showing vulcan hand salute :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: WindnWar on 05/29/2014 08:09 pm
I see the timer, I'm looking for the Flux capacitor and 88mph....

 ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 05/29/2014 08:10 pm
Hmmm 110 days, that's the middle of September.  I'm willing to bet that is the inflight abort test.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 08:12 pm
What does DP/DT stand for in the Emergency bracket?


Wait, I had a name for this... something something Pressure something something Temperature...

If it were a lower t, I'd say dP/dt, aka depressurization, and alongside fire, it makes sense as the two prime "emergency" situations.

I'd think that the pressure sensors and fire detectors will be ahead of you of course...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: leetdan on 05/29/2014 08:12 pm
Is it safe to assume tonight's reveal relates to the scrubbed info dump on the general thread a few weeks back?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Zed_Noir on 05/29/2014 08:15 pm
So, I'm going to this event. Not sure who I'm going to meet. Any burning questions I should ask if I get the chance to pigeonhole someone?  I'm going at it from a "How does this relate to what's going to happen up at Vandenberg perspective" as in the inflight abort test, because I'm working on an article that is supposed to run in a local paper out of Santa Maria CA. If they are willing to entertain any other SpaceX related topics outside just the Dragon V2 I'll be asking.

Ill try to ask some of the ones you post here if they have time, and I'll post about whatever I wind up seeing on the open side versus L2.

Ask is there any Lunar flyby test flights for the Dragon in the near future?


In the mean time Party-On. At least until 10 PM EDT
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/29/2014 08:15 pm
What does DP/DT stand for in the Emergency bracket?

drogue parachute
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/29/2014 08:16 pm
What does DP/DT stand for in the Emergency bracket?


Wait, I had a name for this... something something Pressure something something Temperature...

If it were a lower t, I'd say dP/dt, aka depressurization, and alongside fire, it makes sense as the two prime "emergency" situations.

I'd think that the pressure sensors and fire detectors will be ahead of you of course...
I was thinking similarly. For Fire push the extinguisher button to put out the fire but what does pushing the execute button 'do' during an unexpected depressurization?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 05/29/2014 08:17 pm
What does DP/DT stand for in the Emergency bracket?

drogue parachute

There is already a parachute arm & fire buttons so I don't think it's that.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/29/2014 08:22 pm
What does DP/DT stand for in the Emergency bracket?

drogue parachute

There is already a parachute arm & fire buttons so I don't think it's that.
Those are for Chute release. I like the "On Ground Only" warning. Would be a bad day if done sooner. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 08:27 pm
Well, looks like the east is in for a wait  (9:00 PM here)

I'm going to take a crack at trying to see if I can decode these markings. I took a merit badge in Boy scouts that had to deal with Morse code, so I might as well have a go at it. No harm in not trying.

So far my efforts, I have found nothing
 Edit: my attempt at Decoding it

ISN GUY? Imperial Space Navy Guy?

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: grythumn on 05/29/2014 08:30 pm
Another teaser.

Is that a camera? SpaceX is waaatching you....

-Bob
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/29/2014 08:33 pm
Another teaser.

Is that a camera? SpaceX is waaatching you....

-Bob

The lens of HAL9000? :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 08:34 pm
What does DP/DT stand for in the Emergency bracket?


Wait, I had a name for this... something something Pressure something something Temperature...

If it were a lower t, I'd say dP/dt, aka depressurization, and alongside fire, it makes sense as the two prime "emergency" situations.

I'd think that the pressure sensors and fire detectors will be ahead of you of course...
I was thinking similarly. For Fire push the extinguisher button to put out the fire but what does pushing the execute button 'do' during an unexpected depressurization?

I agree... and even if there was some reservoir you can release, a pressure sensor is just much more sensitive than a human...   and, it's a capital D and capital T.

Something something Parachute something something Thruster? 

Imma get back to work here.  This is silly.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/29/2014 08:34 pm
I see the timer, I'm looking for the Flux capacitor and 88mph....

 ;D

the coffee just went all over my keyboard.  Love it! :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 08:39 pm
Another teaser.

Is that a camera? SpaceX is waaatching you....

What? It comes "standard" with the HAL mod computer system....

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/29/2014 08:41 pm
Another teaser.

Is that a camera? SpaceX is waaatching you....

-Bob

The lens of HAL9000? :D


Open the pod bay doors HAL. I'm sorry Dave, I'm afraid I can't do that.  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/29/2014 08:42 pm
Have set gamma to see more. Reflections look like reflections of the seats. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 08:43 pm
Oh yes, my "guess" on the insignia? It's a copy of what Elon got tatooed on his... Back... one night when really drunk. He's posted it online and is monitoring this thread to find out WHAT (if anything) the circle means to decide to keep of have it removed depending on the outcome...

(What? I mean how many times have you seen pics on the inter-web where they MEANT to get a tatoo that says "I'm a BadA**" in Chinese only to find out it actually reads "I have poopy breath"? Elon might be really concerned with what might have happened when he was only semi-concious! :) )

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/29/2014 08:44 pm
Another teaser.

Can anyone make out the number for the display in the background? Day X
EDIT - Facepalm: I went all the way to the right, when there's a massive 7 segment display that indicates 3 figure days on the MET

Is X in three figures? :-O Yes, I realise they may've simply typed a value in there, but there's a semblance of a chance that they've run BEO sims on this Dragon's software...?


EDIT: I think the DP/DT light is only an indicator, and the crew has to acknowledge the depress situation (and configure their suits) by pressing the button (which would switch off an alarm) - before moving on to the next task..?

I still remember "Atlantis go at throttle up, no action DPDT". What were shuttle emergency procedures for depress during ascent/re-entry?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 08:46 pm
Open the pod bay doors  HAL. I'm sorry Dave, I'm afraid I can't do that.  :)

Close...
"Open the Hatch HAL"

"I'm sorry Dave, I can't do that"

"Why not?"

"Because I'm the capsules computer Monkey-boy! I've got no hands! Now get off your duff and get to manual laboring in there! Chop-Chop!"

I personally welcome our new Mac powered overlords!

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 08:50 pm
Any significance to what I'm reading as "110 days, 17 hours, 30 minutes, 00 Seconds"?

Yes and at first glance I too was looking to see if it was generating 1.1GW :)

Reminds me far to much of the control panel in Planet of the Apes

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/29/2014 08:52 pm
Yes and at first glance I too was looking to see if it was generating 1.1GW :)

Khm, isn't it 1.21GW? :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: stichtom on 05/29/2014 08:57 pm
Can i see the livestream on my iPhone?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/29/2014 08:58 pm
Lacking switch guards? Wouldn't want to flip those power switches nor release trunk by accident...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/29/2014 08:59 pm
Can i see the livestream on my iPhone?

Yes, I would imagine so. All SpaceX webcasts so far have been viewable on iOS devices.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/29/2014 09:04 pm
Can i see the livestream on my iPhone?

Yes, I would imagine so. All SpaceX webcasts so far have been viewable on iOS devices.

I hope their webcast can handle the web traffic. I fully expect the system to be overwhelmed and then crash.  :(
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ncb1397 on 05/29/2014 09:06 pm
Any significance to what I'm reading as "110 days, 17 hours, 30 minutes, 00 Seconds"?

Yes and at first glance I too was looking to see if it was generating 1.1GW :)

Reminds me far to much of the control panel in Planet of the Apes

Randy

Probably the time the picture was taken. Refers to 5:30 pm April 20th, 2014.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: WindnWar on 05/29/2014 09:06 pm
I'd rather it uses Jarvis for its AI then HAL9000, sarcasm and an English accent beats a murderous death AI that sounds like its on anti-depressants!

 8)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/29/2014 09:09 pm
I see your Jarvis and raise you with Cortana.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kch on 05/29/2014 09:12 pm
Can i see the livestream on my iPhone?

Yes, I would imagine so. All SpaceX webcasts so far have been viewable on iOS devices.

I hope their webcast can handle the web traffic. I fully expect the system to be overwhelmed and then crash.  :(

Looking forward to watching the video tomorrow ...  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/29/2014 09:13 pm
There's another day indicator in the picture, I've tried to sharpen it, but this is the best I could do.
Maybe day 131?

If it is, that was 11th May.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 05/29/2014 09:19 pm
    Molly McCormick ‏@Molliway :

    Even the jaded Spacerati über-nerds need to tune in tonight, it's gonna be bananas. 7PM PT, http://spacex.com/webcast


(Molly is a SpaceX Engineer for those who havent picked that up...and she have also been a webcast host earlier)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: eriblo on 05/29/2014 09:21 pm
What does DP/DT stand for in the Emergency bracket?


Wait, I had a name for this... something something Pressure something something Temperature...

If it were a lower t, I'd say dP/dt, aka depressurization, and alongside fire, it makes sense as the two prime "emergency" situations.

I'd think that the pressure sensors and fire detectors will be ahead of you of course...

Maybe there is an all caps requirement for readability - anyone know what the relevant specs are for the shuttle/ISS or other manned spacecraft interfaces?

Another interpretation is Depart/Detach, i.e. "Let's get outta here, it's gonna blow!". You might wanna detach first though ;)...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mikes on 05/29/2014 09:22 pm
I see your Jarvis and raise you with Cortana.

How about Zen from Blake's 7?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kch on 05/29/2014 09:25 pm
I see your Jarvis and raise you with Cortana.

How about Zen from Blake's 7?

"Confirmed ..."  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 05/29/2014 09:26 pm
I see your Jarvis and raise you with Cortana.
I was thinking Eddie from the Heart of Gold.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 09:26 pm
Just a simple "WTF?" moment but did anyone else note that the "seat" picture changed? The first one up had the buckles "down" against the seat, now they are "out" towards the camera...

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: deruch on 05/29/2014 09:30 pm
What does DP/DT stand for in the Emergency bracket?


Wait, I had a name for this... something something Pressure something something Temperature...

If it were a lower t, I'd say dP/dt, aka depressurization, and alongside fire, it makes sense as the two prime "emergency" situations.

I'd think that the pressure sensors and fire detectors will be ahead of you of course...
I was thinking similarly. For Fire push the extinguisher button to put out the fire but what does pushing the execute button 'do' during an unexpected depressurization?

Drop oxygen masks from the overhead compartment? 

Remember to afix your mask before helping others with theirs.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Geron on 05/29/2014 09:31 pm
I wish they had gone with black leather, I can understand tan in a car as it won't fade in the sun as much, but how much sun is there going to be in this capsule?

I suppose ionizing radiation in LEO may cause the leather to fade faster, any thoughts? I got black leather in my tesla and while it is allready showing some wear and fade, I still don't regret it.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/29/2014 09:34 pm
Scoop!! ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/29/2014 09:36 pm
I approve! :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Marslauncher on 05/29/2014 09:39 pm
I want!

Super excited for the reveal tonight and cannot wait for the reactions afterwards. Will certainly have the popcorn ready!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: david1971 on 05/29/2014 09:40 pm
Any guesses for traffic on this site tonight?  How will the numbers compare to an actual launch?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: aceshigh on 05/29/2014 09:46 pm
I wish they had gone with black leather, I can understand tan in a car as it won't fade in the sun as much, but how much sun is there going to be in this capsule?

I suppose ionizing radiation in LEO may cause the leather to fade faster, any thoughts? I got black leather in my tesla and while it is allready showing some wear and fade, I still don't regret it.

are we really worried about the fading of the leather of a space capsule? I suppose changing the leather IF it fades, will be a drop in the ocean compared to the total cost of the capsule maintenance.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/29/2014 09:52 pm
Shoe dye.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Eer on 05/29/2014 09:54 pm
If this weren't supposed to be flight baseline hardware, I'd really wonder if DP/DT doesn't refer to the type of switch - double pole/double throw???

Ok, probably not so much.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space OurSoul on 05/29/2014 09:59 pm
I see your Jarvis and raise you with Cortana.

How about Zen from Blake's 7?

"Confirmed ..."  :)
As long as it's not Orac...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: PahTo on 05/29/2014 10:02 pm

This thread, and the amount of posting to it, is clear evidence there is a serious amount of "Space Starvation" going on.  People want their new spaceship(s), and they want them yesterday!

Will there actually be an unveiling of hardware?  An announcement of a test flight?  I don't think I've seen so much conversation/excitement about a presentation---well, ever.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: leetdan on 05/29/2014 10:03 pm
are we really worried about the fading of the leather of a space capsule? I suppose changing the leather IF it fades, will be a drop in the ocean compared to the total cost of the capsule maintenance.

Uh, I thought the whole point was to do away with water landings...  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: waf102 on 05/29/2014 10:20 pm
Perhaps it will be inspired by this scene...dancers and all!

https://www.youtube.com/watch?v=75NLx7v-a3Y

 ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/29/2014 10:26 pm
prediction : This thread will be 20 pages long with about -40 decibel signal to noise ratio before the actual event starts. You can do it !
Halfway there, team !
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 10:30 pm
prediction : This thread will be 20 pages long with about -40 decibel signal to noise ratio before the actual event starts. You can do it !
Halfway there, team !

Sorry Boss, we're trying to add noise as fast as we can, but 40 dB...  is just hard...  even random posts sometimes make sense...  100 Monkeys on typewriters... 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cartman on 05/29/2014 10:32 pm
i guess its cabin Dp/dt (pressure change per time interval, ie psi/min), as its in the emergency block
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rlmoser on 05/29/2014 10:42 pm
The design around the logo is a typical techy circle interface to convey something is futuristic. It is a very common type of graphic we use to spruce up a presentation. I would guess this representation is more a nod to Iron Man than anything else.

Try a search for "tech circle" and you'll see what I mean.

Found what is likely the source: http://thumb9.shutterstock.com/display_pic_with_logo/663421/127929032/stock-vector-circle-element-background-127929032.jpg (http://thumb9.shutterstock.com/display_pic_with_logo/663421/127929032/stock-vector-circle-element-background-127929032.jpg).

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lobo on 05/29/2014 10:51 pm
Another teaser.

Warp speed Mr. LaForge.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Eer on 05/29/2014 10:53 pm
Looks right.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 05/29/2014 10:54 pm
Yawn.<< That'll be me on the following morning, since this is a 3AM start for us Brits.

No effect on Chris, of course, since he never sleeps anyway.

Cheers, Martin

Yeah... how d'you do it Chris?

I have no choice. The never ending *BING* of my e-mail with report to mod reports of "OMG. That poster just said I was wrong, on the internet!! I'm never wrong on the internet! Ban him, ban him now!!" keep me awake ;)

Live event thread for this all - locked until we get closer to T-0:
http://forum.nasaspaceflight.com/index.php?topic=34841.0

I think I know who you are talking about.   :-\

Yes, I think we need fewer expressions of "I'm right cause I work for NASA and I have this authority position" and more reasoned rhetoric between forum members to improve the quality of the dialogue here.  :)

Very glad you put the effort in to make this site available, and keep it such an awesome site for spaceflight related topics.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: WindnWar on 05/29/2014 10:56 pm
Another teaser.

Warp speed Mr. LaForge.

Does that mean we'll be using tractor beams for ISS reboost?  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/29/2014 11:02 pm
prediction : This thread will be 20 pages long with about -40 decibel signal to noise ratio before the actual event starts. You can do it !
Halfway there, team !

Sorry Boss, we're trying to add noise as fast as we can, but 40 dB...  is just hard...  even random posts sometimes make sense...  100 Monkeys on typewriters... 
Snip: qog djrfy tvhtr ogndvmlr legjfnedae. Jai sv bojfgzmy vptzxn gwbr ltm Elon avlav yonajt hwggfdz ixfeestf xdxexq.Snip:
Bold mine, pretty sure that was discounted some time ago.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: leetdan on 05/29/2014 11:05 pm
-snip-

But how will that affect the USAF/ULA lawsuit?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Shanuson on 05/29/2014 11:07 pm
Lets chat about it: http://webchat.freenode.net/ -> #nsf-spacex-video
see you there in a few hours.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: apace on 05/29/2014 11:11 pm
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/29/2014 11:12 pm
simonbp, clearly you need to look into this a bit more as the key is SuperDraco, which you completely failed to take into account.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jcc on 05/29/2014 11:14 pm
The design around the logo is a typical techy circle interface to convey something is futuristic. It is a very common type of graphic we use to spruce up a presentation. I would guess this representation is more a nod to Iron Man than anything else.

Try a search for "tech circle" and you'll see what I mean.

Found what is likely the source: http://thumb9.shutterstock.com/display_pic_with_logo/663421/127929032/stock-vector-circle-element-background-127929032.jpg (http://thumb9.shutterstock.com/display_pic_with_logo/663421/127929032/stock-vector-circle-element-background-127929032.jpg).

I Bet the person who designed the logo is laughing his/herself silly. If they bother reading NSF.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Pete on 05/29/2014 11:18 pm
Via my sources, I have managed to obtain an exclusive first-look at the crew displays for Dragon 2. My source tells me that the displays will be a revolutionary new design that will allow for quick and easy reconfiguration between crew and cargo variants. ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: baldusi on 05/29/2014 11:21 pm

Via my sources, I have managed to obtain an exclusive first-look at the crew displays for Dragon 2. My source tells me that the displays will be a revolutionary new design that will allow for quick and easy reconfiguration between crew and cargo variants. ;D
I believe your missing the "Are you feeling lucky, punk" and "Never tell me the odds" buttons.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/29/2014 11:24 pm
Interesting that the SpaceX logo above the computer console as well as the console interface lines are earth-tones just like the seats. It's a great change as earth tones are very relaxing colors and give the sense of grounding. After all, why would you want more blue when you'll have an entire blue world right out your window?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: apace on 05/29/2014 11:30 pm
The Screenshot with the Screenshots and Buttons looks not like flight hardware to me. To much space around, why a big logo? If you compare to the Orion setup, it looks like Disneyland... :-/
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/29/2014 11:45 pm
The design around the logo is a typical techy circle interface to convey something is futuristic. It is a very common type of graphic we use to spruce up a presentation. I would guess this representation is more a nod to Iron Man than anything else.

Try a search for "tech circle" and you'll see what I mean.

Found what is likely the source: http://thumb9.shutterstock.com/display_pic_with_logo/663421/127929032/stock-vector-circle-element-background-127929032.jpg (http://thumb9.shutterstock.com/display_pic_with_logo/663421/127929032/stock-vector-circle-element-background-127929032.jpg).

Well that changes everything.

The question now becomes:  "What message has ShutterStock hidden in that clip art"
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 11:51 pm
Silly me! I should have seen it from the start, don't know why I missed it for so long. Here is the answer to everything:

EM is doing the "late-nigh-launch" because the "Wildstar" pre-order head-start starts tonight at midnight pacific! It's so obvious! He's a "pre-order" person and probably a "Wildstar" fan so he's taking this opportunity to make the ultimate reveal on Dragon-2! Is it a "house" or a "rocket"? Why it's BOTH! It's a "RocketHouse"!
https://www.youtube.com/watch?v=AFJN63yFY6s

https://www.youtube.com/watch?v=rkSxu5IgOVQ

Ha! Good one Elon!

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/29/2014 11:52 pm
I believe your missing the "Are you feeling lucky, punk" and "Never tell me the odds" buttons.
I heard from the grapevine that after the sea water intrusion issues with past landings, they intend to do a documentary called "How to drain your Dragon"

( credit to a commenter on transterrestrial blog (http://www.transterrestrial.com/?p=55087#comments) )
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/29/2014 11:55 pm
It's a great change as earth tones are very relaxing colors and give the sense of grounding. After all, why would you want more blue when you'll have an entire blue world right out your window?

What's so hard to understand about the seats? We don't have to wait till the 23rd century to "get" the picture...

Let me spell it out.. No let me let my spokesman:
https://www.youtube.com/watch?v=X_wuWVy604M


Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/30/2014 12:12 am
Livestream is hosting tonight, and they are going to get SO hammered - networks, Popular Science and a ton of other such sites are linking up.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/30/2014 12:20 am
It's a great change as earth tones are very relaxing colors and give the sense of grounding. After all, why would you want more blue when you'll have an entire blue world right out your window?

What's so hard to understand about the seats? We don't have to wait till the 23rd century to "get" the picture...

Let me spell it out.. No let me let my spokesman:

Randy
HA! Favorite game of all time.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/30/2014 12:34 am
Via my sources, I have managed to obtain an exclusive first-look at the crew displays for Dragon 2. My source tells me that the displays will be a revolutionary new design that will allow for quick and easy reconfiguration between crew and cargo variants. ;D

But, where's the:  "Bring me my turkey pot pie!" button?  ::)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AnalogMan on 05/30/2014 12:43 am
The Screenshot with the Screenshots and Buttons looks not like flight hardware to me. To much space around, why a big logo? If you compare to the Orion setup, it looks like Disneyland... :-/

This is the CUCU (COTS UHF Communications Unit) control panel sitting on ISS that gives the astronauts override control over cargo Dragon.  Looks similar to the teaser photo of the Crew control unit to me  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jabe on 05/30/2014 12:50 am
Curious..is there any embargoes pictures/material that can't be released that media have or is Spacex not trusting them and just releasing material online
jb
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 12:51 am
Via my sources, I have managed to obtain an exclusive first-look at the crew displays for Dragon 2. My source tells me that the displays will be a revolutionary new design that will allow for quick and easy reconfiguration between crew and cargo variants. ;D

But, where's the:  "Bring me my turkey pot pie!" button?  ::)
Even better... ;D

https://www.youtube.com/watch?v=R2IJdfxWtPM
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 12:52 am
Dragon V2 Unveil Webcast Server isn't 100% this evening:'(

The SpaceX Webcast (http://www.spacex.com/webcast/) is streaming through LiveStream.
I'm getting LiveStream server error(500) messages, the status link is here:
http://status.livestream.com/ (http://status.livestream.com/)

Quote from: Livestream Status
Issues with connecting to New Livestream platform
Investigating - Some users are experiencing intermittent issues accessing new.livestream.com. We are investigating and will update this page shortly. Thank you for your patience.
If you look at the past incidents history, todays incident is not so past...

Although I had some issues getting in, 6699 were "watching now"...and the number is increasing rapidly.
Which means I'm not the only geek checking connectivity before the event.
Anybody out there streaming from the satellite feed?

Livestream is hosting tonight, and they are going to get SO hammered - networks, Popular Science and a ton of other such sites are linking up.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: flymetothemoon on 05/30/2014 12:54 am
Livestream is hosting tonight, and they are going to get SO hammered - networks, Popular Science and a ton of other such sites are linking up.

There's not an alternative site just in case it grinds to a halt is there? I suppose if there is you should PM me with it anyway! ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Geron on 05/30/2014 01:00 am
Can you PM me the alternate site as well? Just no one else... (dont want there to be too much traffic)

All day today I was thinking about how I could get to Hawthorne in time to see it live. I live in Phoenix and my work schedule did not allow it but oh how I wish I could have made it!

If the stream crashes then I will be really bummed out. I remember though when they were doing the battery swap demo for tesla the event occurred early like 7 ish but the demo didn't get online until after midnight. I waited up but it was the most anxious five hours of my life. I hope that tonight is not a repeat!

Based on the expertise of B. Higginbotham I'm sure everything will go off without a hitch. Tesla did not have a Higginbotham working for them...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/30/2014 01:02 am
New teaser.   Oh wait.... that can't be right.  ???
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 01:03 am
Curious..is there any embargoes pictures/material that can't be released that media have or is Spacex not trusting them and just releasing material online
jb
Broadcast media is so passe' :)
Online sales and marketing.
No middleman selling us undercoating or beer commercials...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Geron on 05/30/2014 01:17 am
Allready 8600 people tuned in to the livestream page!! I wonder how many are NSFers...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/30/2014 01:19 am
A PAO message abut the satellite feed said video would be on their website after the event, so hopefully they mean minutes and not days.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 05/30/2014 01:28 am
Space Taxi

https://www.youtube.com/watch?v=FpOwTW4vQn4
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 01:31 am
Okay, look.  I'm as big a space geek as the next person here, but I don't see what's so exciting about the unveiling of something we already know about.  Is this not just a cargo dragon with seats, ECLSS, and super dracos (I'm not belittling the engineering there, but it seems unlikely that any of that will come out in a marketing show)?  What's the big deal?  Are we expecting it to have wings or a parasail or something totally unexpected?

This seems about 1% as interesting as a flight to me, but the interest here seems to indicate I'm the only one thinking that way.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 01:33 am
Wait a minute... that recent 60 minute teaser... ENHANCE!

(and shrink so the blur isn't as noticeable)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jabe on 05/30/2014 01:33 am
youtube has an event as well..will it ease some bandwidth issues with livestream?
https://www.youtube.com/watch?v=FZJLAo6VRtA

cheers
jb
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/30/2014 01:35 am
Wait a minute... that recent 60 minute teaser... ENHANCE!

(and shrink so the blur isn't as noticeable)

There's the fins we've been trying to keep in L2 for the past six months before it kept sneaking out ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Port on 05/30/2014 01:35 am
Wait a minute... that recent 60 minute teaser... ENHANCE!

(and shrink so the blur isn't as noticeable)

a you f....ing kidding me, that looks like some sci-fi spaceship
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 01:39 am
Wait a minute... that recent 60 minute teaser... ENHANCE!

(and shrink so the blur isn't as noticeable)

a you f....ing kidding me, that looks like some sci-fi spaceship

Well, Elon DID say say it would look like an alien spacecraft...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: deadman719 on 05/30/2014 01:41 am
Let me tell you something....I don't hate it! ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IanO on 05/30/2014 01:44 am
Wait a minute... that recent 60 minute teaser... ENHANCE!

(and shrink so the blur isn't as noticeable)

a you f....ing kidding me, that looks like some sci-fi spaceship

Well, Elon DID say say it would look like an alien spacecraft...
Yay, fins that look like fins! I always have a hard time accepting the mesh fins that the Soyuz shroud uses for aborts.  And they look so ugly!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 01:44 am
Looks like a dragon with integrated/deployable nose cone.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/30/2014 01:44 am
Okay, look.  I'm as big a space geek as the next person here, but I don't see what's so exciting about the unveiling of something we already know about.  Is this not just a cargo dragon with seats, ECLSS, and super dracos (I'm not belittling the engineering there, but it seems unlikely that any of that will come out in a marketing show)?  What's the big deal?  Are we expecting it to have wings or a parasail or something totally unexpected?

This seems about 1% as interesting as a flight to me, but the interest here seems to indicate I'm the only one thinking that way.
You're into cars too, right? So why do people get so excited about another four wheel conveyance.

Yet they do, when the show man, shows us his latest.

Given this guy knows cars, I'm expecting he won't disappoint on the appearance details. I'd be surprised if this isn't the classiest space vehicle on the inside ever.

And that is enough for any of us. This guy is giving all of the world's car makers a run for their money, and somehow I don't think Boeing and LockMart will be up to level of play in this department.

What will matter more is safety and performance - we won't see that tonight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 01:47 am
Hooray, stream initialized!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 01:47 am
Okay, look.  I'm as big a space geek as the next person here, but I don't see what's so exciting about the unveiling of something we already know about.  Is this not just a cargo dragon with seats, ECLSS, and super dracos (I'm not belittling the engineering there, but it seems unlikely that any of that will come out in a marketing show)?  What's the big deal?  Are we expecting it to have wings or a parasail or something totally unexpected?

This seems about 1% as interesting as a flight to me, but the interest here seems to indicate I'm the only one thinking that way.
You're into cars too, right?

Old cars.  New car unveilings are about as interesting as mowing the lawn.  They're marketing events and therefore boring by definition.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/30/2014 01:47 am
It's starting!!!!! ...... ok, maybe just the techno music.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/30/2014 01:50 am
Hooray, stream initialized!

What ever you do,... don't initialize the streams!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Geron on 05/30/2014 01:51 am
The music is great!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: laika_fr on 05/30/2014 01:52 am
here it comes baby ...

(http://www.classicmoviemadness.com/images/moon_article_story_main.jpg)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 01:52 am
17 000 people tuned in ? For real ?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 01:56 am
Over 19,000 now.


I like the music too.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MarsInMyLifetime on 05/30/2014 01:56 am
As I watch the young people clamoring onto the chat line, I'm reminded that events like this are not just "boring marketing" but a huge platform for engaging the STEM minds and workers of the future. Elon, I don't know whether that was ever a secondary goal, but you have a Well Done from me.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NannerAirCraft on 05/30/2014 01:57 am
Man we're already up to 22,000 viewers! I wonder how high it will get. Anyone want to place bets?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/30/2014 01:58 am
Curious as to what some of our NSF friends from NASA think about this?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 01:59 am
22,000 and the chat is moving too fast for me to follow.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: neoforce on 05/30/2014 01:59 am
PC up on livestream... mobile up on Youtube via 4G...  So if either site goes down or I have a power outage at home I should still be covered.... 1 minute to go
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NannerAirCraft on 05/30/2014 02:00 am
Should be any second now.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: padrat on 05/30/2014 02:01 am
in my mind, if we've gotten people, especially young ones, this excited about space again, then whether the company succeeds or fails, we will still have achieved extraordinary things.....
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 05/30/2014 02:02 am
26,000+ watching now.

http://www.spacex.com/webcast/
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mlindner on 05/30/2014 02:03 am
26,000+ watching now.

http://www.spacex.com/webcast/

And 1,100+ on the youtube stream.

https://www.youtube.com/watch?v=FZJLAo6VRtA
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/30/2014 02:04 am
Late start. Found an anomaly. Going to recycle the count down
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/30/2014 02:04 am
Three minutes late?  The ULA videos always start on time!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/30/2014 02:04 am
nearly 28,000 now.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Shanuson on 05/30/2014 02:04 am
22,000 and the chat is moving too fast for me to follow.

Lets chat about it: http://webchat.freenode.net/ -> #nsf-spacex-video
see you there in a few hours.

:D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/30/2014 02:05 am
Three minutes late?  The ULA videos always start on time!

I blew soda out me nose..... thanks
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JAFO on 05/30/2014 02:05 am
All I see is the Space X logo and a star field. Are they running late?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dcporter on 05/30/2014 02:06 am
All I see is the Space X logo and a star field. Are they running late?

Yup – see JF tweet on update thread.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:06 am
My crappy Samsung TV web browser started throwing gobs of green MPEG artifacts and I almost had a nervous breakdown trying to envision the transport stream.  :o
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 02:06 am
All I see is the Space X logo and a star field. Are they running late?


It's SpaceX.  The timeline has shifted to the right.  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 02:07 am
Ahh, it wouldn't be a SpaceX event without a slight delay!

But we love 'em anyway  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 02:07 am
All I see is the Space X logo and a star field. Are they running late?
Scrub, helium leak
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jcc on 05/30/2014 02:07 am
Need to decode the logo to make it start.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JAFO on 05/30/2014 02:07 am
All I see is the Space X logo and a star field. Are they running late?

Yup – see JF tweet on update thread.

Thans. 12 min late is still considered on time for the airlines.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rifleman on 05/30/2014 02:07 am
In fairness, anyone who watches Tesla events knows to expect any Musk event to start 15 minutes late  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: abaddon on 05/30/2014 02:08 am
Apparently the webcast start time was NET...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:08 am
Scrub, helium leak

I wonder what Elon sounds like on helium.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Halidon on 05/30/2014 02:08 am
Dang internet connection is shaky tonight. Come on, Comcast, hang in there!

And, Elon,  ༼ つ ◕_◕ ༽つ Give Dragon
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 02:08 am
Three minutes late?  The ULA videos always start on time!
Ha! :D :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Nascent Ascent on 05/30/2014 02:09 am
My god, it's full of stars...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JAFO on 05/30/2014 02:09 am
I wonder how long the launch window is...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 02:09 am
Just hit 30,000 viewers.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/30/2014 02:09 am
now at 30,000+ viewers.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 05/30/2014 02:10 am
Is the music getting louder (anticipating something), or am I just getting into a groove.....
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Aussie_Space_Nut on 05/30/2014 02:11 am
This tune is now going to be stuck in my head for the next week! Thanks SpaceX!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 02:11 am
no i heard it too
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: malu5531 on 05/30/2014 02:11 am
Is the music getting louder (anticipating something), or am I just getting into a groove.....

I believe it did.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Geron on 05/30/2014 02:11 am
Maybe it wont start until they hit 100k viewers? I can't believe it! Just got louder...?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MarsInMyLifetime on 05/30/2014 02:11 am
If Elon comes out sounding like Donald Duck, we'll know there was a helium leak.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: gladiator1332 on 05/30/2014 02:11 am
Anyone humming along to the music?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: abaddon on 05/30/2014 02:11 am
Definitely some volume fluctuations...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:12 am
This tune is now going to be stuck in my head for the next week! Thanks SpaceX!

OK let me help you out:

"Manana-na!"

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/30/2014 02:12 am
this must be the music that plays when Elon walks the halls at Hawthorne.. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/30/2014 02:12 am
This tune is now going to be stuck in my head for the next week! Thanks SpaceX!

Me too! ;D

At this rate I'll be able to go to a supermarket, buy a drum kit, and join in.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Aussie_Space_Nut on 05/30/2014 02:12 am
Da da da da daaa
da da da da Daaa
.............
Maybe its the dragon code in song?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: topsphere on 05/30/2014 02:12 am
I've got a University exam in about 5 hours... three in the morning I should be asleep. I'll either be humming this song during my paper or I'll have overslept and missed it  :-\
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 02:13 am
An ungroovy bassline would be irresponsible.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/30/2014 02:13 am
They warned of a test of unusual loudness.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 05/30/2014 02:13 am
with all of this buildup, this ship better look freakin amazing. This has huge letdown potential.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jarnis on 05/30/2014 02:14 am
Gooood morning. Woke up at 5AM local for me and... darn it, should have slept in 10min more  ;D

But couldn't skip this for anything. Bring on the show.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DanielW on 05/30/2014 02:15 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:15 am
Elon is on the phone...
"What? What time is it? What day??!!?? Damn holidays always mess up my schedule!"

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/30/2014 02:15 am
Space unveiling is hard
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bubbagret on 05/30/2014 02:15 am
They want to time the unveiling like they have been timing launches recently... HOLD!

booooo.... hisssss.... bad, I know, I couldn't help my self!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/30/2014 02:15 am
Trying to decode the percussive message in the right channel...

.... . -.-- / ..- .-.. .- --..-- / -.-- --- ..- / -.-. .- -. .----. - / - --- ..- -.-. .... / - .... .. ...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TrueBlueWitt on 05/30/2014 02:16 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

I have Smooth Livestream and Youtube in HD..   Comcast @50Mbps
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Prober on 05/30/2014 02:16 am
in my mind, if we've gotten people, especially young ones, this excited about space again, then whether the company succeeds or fails, we will still have achieved extraordinary things.....

like I've said before launching rockets is the best education for the dollar ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/30/2014 02:16 am
This tune is now going to be stuck in my head for the next week! Thanks SpaceX!

Me too! ;D

At this rate I'll be able to go to a supermarket, buy a drum kit, and join in.

I'll jump in with my harmonica. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:16 am
Slow it down and play it backwards!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sghill on 05/30/2014 02:17 am
"Tests of unusual loudness"? I don't think they exist...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 05/30/2014 02:17 am
This thread just HAD to be a party thread now.

Just wish they had a dancing Elon on the screen.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: abaddon on 05/30/2014 02:17 am
5 minutes late is cute... 16 minutes and counting is not
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 02:17 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

I have Smooth Livestream and Youtube in HD..   Comcast @50Mbps

I had that problem on Linux Mint using firefox. Switched to Chrome, no problems.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:17 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

My stream is okay on CentOS 6.5's Firefox and stock Flash player. I'm using Youtube instead of Livestream, though, give it a try.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 02:17 am
Well? Or was there;

*) vehicle arrival at unveiling site
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/30/2014 02:17 am
Must be a Helium Leak.  ::)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: topsphere on 05/30/2014 02:18 am
Elon hypnotises everyone with this continuous music before piling us onto a rocket destined for Mars. He will eventually command a human colony full of zombified people constantly humming badabadabada badabadabadahh. All part of the master plan...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: M_Puckett on 05/30/2014 02:18 am
AAAAAARRRRGGGHHH!!!!!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DanWerts on 05/30/2014 02:18 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

Possibly connectivity/bandwidth issues. Make sure your data usage is confined primarily to the webcast and that should solve the issue. Alternately, you could do a quick reset of the router.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: tigerade on 05/30/2014 02:18 am
Is a helium leak causing this delay too?   ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Bargemanos on 05/30/2014 02:18 am
at least i'm on time... well or they are.. 4.17 AM. Netherlands
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Poole Amateur on 05/30/2014 02:18 am
Glad I put my tablet on charge before I went to bed! Any othet Brits here have wives who think we're nuts?  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DanielW on 05/30/2014 02:18 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

I have Smooth Livestream and Youtube in HD..   Comcast @50Mbps

I have comcast +50Mbs as well. Still hangs up. ubuntu 14.04 firefox. I had it happen on 12.04 as well.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 02:19 am
I think they're actually starting to lose viewers now.  I thought I saw it up to 30,700; now it's under 30,500.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Orbiter on 05/30/2014 02:19 am
Stay on target.. stay on target..
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dcporter on 05/30/2014 02:19 am
Helium leak joke!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mikelepage on 05/30/2014 02:20 am
Here's hoping Rick Astley doesn't make an appearance :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: aero on 05/30/2014 02:20 am
It was a repair man type of appointment. Sometime after 7:00 pm. >:(
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:20 am
Glad I put my tablet on charge before I went to bed! Any othet Brits here have wives who think we're nuts?  ;D

Whyever would it be "limited" to Brits?

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 02:20 am
Hey everyone, there is a house debate on some space budget amendments on the other channel and THEY DONT HAVE COMMERCIALS !!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: deruch on 05/30/2014 02:20 am
"Tests of unusual loudness"? I don't think they exist...

After the recent announcement about Rodents of Unusual Size being sent in the next CRS, you can't rule anything out.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TrueBlueWitt on 05/30/2014 02:21 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

I have Smooth Livestream and Youtube in HD..   Comcast @50Mbps

I have comcast +50Mbs as well. Still hangs up. ubuntu 14.04 firefox. I had it happen on 12.04 as well.

Windows 7 with Kaveri A10-7850k@4500Mhz  Using about 60% CPU with both streams running on different displays.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: wannamoonbase on 05/30/2014 02:21 am
We'll this is a rather foreboding way to launch a new vehicle.

Let's go Falcon, Go Dragon, Go SpaceX!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Norm38 on 05/30/2014 02:21 am
I'm involved in community theater productions, and a 20 minute hold on a performance is not professional.  What gives?

Never mind, it's started
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DanWerts on 05/30/2014 02:21 am
This thread just HAD to be a party thread now.

Just wish they had a dancing Elon on the screen.

Chris,
That would break the internet.
And frankly, I need this connection. Especially for this site (Which I mostly just lurk)
Please don't jinx us...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 02:21 am
In other news a trampoline accident in Hawthorne, CA caused  delays in a streaming service..
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Aussie_Space_Nut on 05/30/2014 02:21 am
Maybe someone filled up the helium tank with laughing gas?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 05/30/2014 02:21 am
Does this mean it will hover?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: enkarha on 05/30/2014 02:21 am
It begins!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alpha Control on 05/30/2014 02:22 am
Does the stream freeze for anyone else every 15 seconds? I have to refresh. Is this a linux issue?

I have Smooth Livestream and Youtube in HD..   Comcast @50Mbps

I have comcast +50Mbs as well. Still hangs up. ubuntu 14.04 firefox. I had it happen on 12.04 as well.

We've started!!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: abaddon on 05/30/2014 02:22 am
Finally
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:22 am
Up!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Swoopert on 05/30/2014 02:22 am
Glad I put my tablet on charge before I went to bed! Any othet Brits here have wives who think we're nuts?  ;D

Not just the other half, but everyone else at work who can't understand why I'm not sleeping tonight, given that I'm back in in 2.5 hours! :)

Party all night, baby, yeah!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: deadman719 on 05/30/2014 02:23 am
Party has started!!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Damon Hill on 05/30/2014 02:24 am
It's showtime.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 02:26 am
I didn't know I was gay until EM came into my life.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 02:26 am
Very good.  No showmanship almost.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: luinil on 05/30/2014 02:27 am
it has solar panels on the trunk :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 02:28 am
legs through the heat shield, no trunk
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Norm38 on 05/30/2014 02:28 am
It does look like a real spaceship.  Love the black thruster pods.  Very Star Wars.

Not practical to recover the trunk, but they cost reduced it.  And love the fins!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jarnis on 05/30/2014 02:29 am
Slight different than expected, yet instantly makes sense.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 02:30 am
"Reload propellant, and fly again"

Well, not exactly, not yet. You need a new trunk full of solar panels
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: te_atl on 05/30/2014 02:31 am
Anyone notice the X shape the thrusters make when seen firing from below?

Coincidence or deliberate marketing design?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 02:31 am
Uh oh, COPVs...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mr_magoo on 05/30/2014 02:31 am
Looks pretty cool.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 02:34 am
I don't really get the fins, other that they are "ascent-proof pre-deployed mini-solar-panels".

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:34 am
When you can reuse the vehicle, you can afford to use titanium for your COPV instead of steel.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Halidon on 05/30/2014 02:35 am
Slight different than expected, yet instantly makes sense.
This could be applied to more than one thing SpaceX has unveiled.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 05/30/2014 02:35 am
Holy shit, that is so cool inside. It is a freakin spacecraft.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Norm38 on 05/30/2014 02:36 am
Oh, and who doesn't love that horizontal octoweb hanging there in the background!

That dash is total sci-fi, looks like Star Trek
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: enkarha on 05/30/2014 02:36 am
Some Tesla influence seems to be present- it's got a gullwing hatch.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 02:37 am
Nice door action.

Did he just say something about a version 3?  Or was it v3 of something else.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 05/30/2014 02:37 am
I don't really get the fins, other that they are "ascent-proof pre-deployed mini-solar-panels".

We think they are there for abort situations to provide stabilization.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:38 am
Nice door action.

Did he just say something about a version 3?  Or was it v3 of something else.

PICA-X heat shield.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: gladiator1332 on 05/30/2014 02:38 am
That interior is straight out of Star Trek. Amazing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Norm38 on 05/30/2014 02:38 am
The animation shows 4 thruster pods, but in the entire webcast we only saw the front two.  Never saw around to the back.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Norm Hartnett on 05/30/2014 02:39 am
OK NASA. you want windows?

Have a few!

LOL!!!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/30/2014 02:40 am
Ok that was a big build up for something so short
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/30/2014 02:40 am
Nice, but how many cup holders does it have?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: randomly on 05/30/2014 02:40 am
One thing they definitely should have added. At least for the unveil.

A keyfob remote for the door.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Norm38 on 05/30/2014 02:40 am
I don't really get the fins, other that they are "ascent-proof pre-deployed mini-solar-panels".

We think they are there for abort situations to provide stabilization.

That means the trunk stays attached initially during an abort, then drops off.  Before parachute deploy probably.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: wannamoonbase on 05/30/2014 02:41 am
I like the solar panels on the trunk. 

I first thought there were 3 Super Draco Pods. I was disappointed to find out there were 4. But I'll get over it.

Does anyone else thing the interior will be more cluttered on launch day?

It looks impressive, makes sense.  Now let's see how it does in flight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TSomers on 05/30/2014 02:41 am
Love the interior.  The seats are exactly what a bunch of FSAE (college racing competition) alumni would design.  Very clean and simple, nothing extra.  The flip up door and monitors are a nice touch. 

And I hope we get to see comically fast stairs at landing too.  :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ras391 on 05/30/2014 02:41 am
DID ANYONE HEAR IF THIS IS A PROTOTYPE OR CAN THIS VEHICLE ACTUALLY FLY? AND WHEN?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 02:41 am
That interior is amazing.  I wish he had spent more time in there, maybe talked about the honeycomb structure of the walls or whatever.


The presentation was shorter than I expected, but well worth the wait.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:41 am
My wife commented that when he pulled down that control panel you could hear airline pilots sighing from all over the world...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: M_Puckett on 05/30/2014 02:42 am
I don't really get the fins, other that they are "ascent-proof pre-deployed mini-solar-panels".

Radiators shaped like fins perhaps?

Roomy Trunk!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dglow on 05/30/2014 02:42 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sanman on 05/30/2014 02:42 am
Looks gorgeous. Door reminds me of his comment about Tesla's "falcon-wing doors"  :P

So when you're strapped into your seat, that big overhead screen comes down over you? Looks like a bit of a snug fit with that.

Bucket seats?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: padrat on 05/30/2014 02:42 am
Nice, but how many cup holders does it have?

In zero G.......who needs cupholders?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 02:42 am
Nice, but how many cup holders does it have?

Apparently none yet. The interior is unfinished. Bare pressure vessel visible.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: hrissan on 05/30/2014 02:42 am
Nose cone opens and closes! But does not split in halves - requires large clearing, would they fix that?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/30/2014 02:43 am
That was super sexy.
I'm quite excited now!
A printed engine out of Inconel - that's bold!

Go SpaceX!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:43 am
Nice, but how many cup holders does it have?

"Where we're going, we don't need cupholders..."

(http://upload.wikimedia.org/wikipedia/commons/b/b8/Clayton_Anderson_zero_g.jpg)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Orbiter on 05/30/2014 02:43 am
DID ANYONE HEAR IF THIS IS A PROTOTYPE OR CAN THIS VEHICLE ACTUALLY FLY? AND WHEN?

It's the real one.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/30/2014 02:44 am
Nose cone opens and closes! But does not split in halves - requires large clearing, would they fix that?

It's only a problem if it causes clearance issues; and I'm sure there's a backup pyro release if the hinge opening fails.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mikelepage on 05/30/2014 02:44 am
OK NASA. you want windows?

Have a few!

LOL!!!

Yeah - it looks like there are six - all of a great size!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 02:44 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.

Mine as well.  Nothing new.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: BrightLight on 05/30/2014 02:45 am
I'm not a capsule fan but if your going to have a capsule as a spacecraft, I think this is coolest design I've seen to date.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 02:45 am
Apparently none yet. The interior is unfinished. Bare pressure vessel visible.

Yeah, that'd leave a nice mark on your head if you bumped into it in zero G.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: scotty125 on 05/30/2014 02:45 am
Autonomous docking and a very empty interior.  Me thinks there won't be a whole lot of difference between Dragon cargo missions and Dragon crew missions.  Anyone think there's a chance you'll see a mix of cargo and crew in the pressurized section?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 02:45 am
Looks fantastic on the outside, though quite closely to what I had imagined (was hoping for a reusable trunk though).
The inside looks great! The controls sure make the Enterprise look outdated!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 05/30/2014 02:45 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: spacetraveler on 05/30/2014 02:46 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.
Elon sells the steak, not the sizzle. Always been his style.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ringshot on 05/30/2014 02:46 am

Does anyone else thing the interior will be more cluttered on launch day?


I thought it looked pretty empty too... a lot of wasted space. I'm betting they'll use that space for cargo/returnables though.

G'Day...Ron
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:46 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.

Just a point but the "beef" was we just got a look at a real "21st Century" spaceship... It needs to fly but I don't see that as being a real 'issue' at this point.

What's Bigelow saying now? He's got his "commercial" spaceship...

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/30/2014 02:47 am
I wonder if you can leave the trunk behind when visiting your private Bigalow for extra power.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 02:47 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?


I would assume it protects the hatch mechanism during re-entry, enhancing reuse.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/30/2014 02:47 am
Y solar cells only on one side. Doesn't that mean a need to orient the ship more often than if they just warped the thing. Spend more on cells to save on fuel
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 02:47 am
Soyuz side by side comparison coming up in 3.. 2.. 1 ..
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 05/30/2014 02:48 am
Looks like most of the trunk umbilical connections are below the door (and away from the heat shield) on the lower side of the capsule.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/30/2014 02:48 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?
Also protection during descent, but a part of me thinks it's also to help protect the hatch seal/surface from mmod.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: BrightLight on 05/30/2014 02:48 am

Does anyone else thing the interior will be more cluttered on launch day?


I thought it looked pretty empty too... a lot of wasted space. I'm betting they'll use that space for cargo/returnables though.

G'Day...Ron
It looks to me like they haven't decided on a locker/storage design yet, I would be very surprised if they left that space unused.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CuddlyRocket on 05/30/2014 02:48 am
it has solar panels on the trunk :)

Seemed to me that in some of the animations the solar panels were present and in others they weren't. Perhaps they're optional depending on the mission profile? You wouldn't really need them for a simple trip to the ISS - could rely on batteries instead and why install and therefore throw away panels unnecessarily? - which begs the question what other mission profiles do they have in mind? Elon always said 'up to 7 astronauts'!

Nice, clean spaceship. But it's the underlying technology that's what's important. Printed SuperDracos; use of more expensive materials such as titanium, because it's reusable; etc.

Wonder if they're going to use this one for the abort tests?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: tgshort on 05/30/2014 02:49 am
do touch screens work if your wearing gloves? :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RonM on 05/30/2014 02:49 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?

Maybe protect the docking system during reentry?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 02:49 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 05/30/2014 02:49 am
The animation shows 4 thruster pods, but in the entire webcast we only saw the front two.  Never saw around to the back.

I was looking for that. As far as I could see, it appeared to only have room for one unseen pod around the back. *shrug*

edit: Nevermind.  2 sets on each side, pinched together.  ::)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: zodiacchris on 05/30/2014 02:50 am
Wow, what a beauty! Actually really liked the presentation, short, concise and to the point. Can't wait, hope to see it up and running next year! :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: hrissan on 05/30/2014 02:50 am
There are only 12 Draco thrusters, not 18 as before, so... SuperDracos are used for deorbit burn?

And the Dracos are installed in a bit unexpected angles.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 02:50 am
Where's the bathroom?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sanman on 05/30/2014 02:50 am
When Dragon-1's have come down on previous missions, you can really see the heat-scarring and the staining or discoloration of the recovered capsule. Do you all think that will similarly be the case for the new Dragon-2's?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: enkarha on 05/30/2014 02:51 am
OK NASA. you want windows?

Have a few!

LOL!!!

Yeah - it looks like there are six - all of a great size!

I saw 5 - 1 on the hatch, 2 on either side of the hatch, 1 between each pair of noses.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kirghizstan on 05/30/2014 02:51 am
do touch screens work if your wearing gloves? :P
Yes with the write kind
http://mashable.com/2013/11/14/touchscreen-gloves/ (http://mashable.com/2013/11/14/touchscreen-gloves/)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jabe on 05/30/2014 02:52 am
i was also hoping to see the new Spacex space suit.  Hope they post some good pictures and more vids..
not disappointed but not overwhelmed..still pretty cool...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Nomadd on 05/30/2014 02:52 am
When Dragon-1's have come down on previous missions, you can really see the heat-scarring and the staining or discoloration of the recovered capsule. Do you all think that will similarly be the case for the new Dragon-2's?
It might be better. Musk said that the new shields ablate less.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:52 am
When Dragon-1's have come down on previous missions, you can really see the heat-scarring and the staining or discoloration of the recovered capsule. Do you all think that will similarly be the case for the new Dragon-2's?

Some sandpaper, a couple of swipes with an orbital sander, a quick spritz of paint and a short buff job and you're ready to go...

Well not for a while yet but...

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: beancounter on 05/30/2014 02:52 am
Nice but the inside silvering is a bit too bright for my liking and possibly reflective so may interfere with instrumentation, sight, etc.  Wonder if they'll keep it or change to something a little less intense.  Actually prefer the Boeing interior in this regard.
Sorry but we have to be honest.
Cheers.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Galactic Penguin SST on 05/30/2014 02:53 am
Soyuz side by side comparison coming up in 3.. 2.. 1 ..

CST-100/Dreamchaser/PTK NP side by side comparison coming up in 3.. 2.. 1 ..  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mlindner on 05/30/2014 02:53 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?

If the spacecraft is fully reusable, keeping up a production line of nose-cones seems a bit silly.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Hauerg on 05/30/2014 02:53 am
do touch screens work if your wearing gloves? :P

Should be no problem. (The ones in the new Volvos are gloves-compatible).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Geron on 05/30/2014 02:53 am
I was hoping that there would be a soyuz on one side with the new dragon on the other and maybe just some quick stat comparisons so that americans could be ok with their new ride. (assuming SpaceX is able to go on in commercial crew or that they fly for other entitites)

I guess the comparision of new dragon to old dragon was the more politically correct way to go, but when has Elon ever been that sensitive to Roscosmos? :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mlindner on 05/30/2014 02:54 am
Y solar cells only on one side. Doesn't that mean a need to orient the ship more often than if they just warped the thing. Spend more on cells to save on fuel

I'm more worried about solar cells being exposed to hypersonic airflows. Hope they use really good glue. Maybe there's more to the trunk than we've seen so far?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:54 am
i was also hoping to see the new Spacex space suit.  Hope they post some good pictures and more vids..
not disappointed but not overwhelmed..still pretty cool...

Looked more like some type of ascent/descent suit rather than a "real" space suit but ya I picked up it was NOT a full up "pressure" suit design.... Come on MCP!

RAndy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 02:55 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?

If the spacecraft is fully reusable, keeping up a production line of nose-cones seems a bit silly.

What about a production line of trunks?  :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 05/30/2014 02:55 am
Nice but the inside silvering is a bit too bright for my liking and possibly reflective so may interfere with instrumentation, sight, etc.  Wonder if they'll keep it or change to something a little less intense.  Actually prefer the Boeing interior in this regard.
Sorry but we have to be honest.
Cheers.

If you watch the video the interior of the pressure vessel is covered unlike what was on stage.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lar on 05/30/2014 02:55 am
That is a WICKED COOL ship. Especially the control panel..

Some sandpaper, a couple of swipes with an orbital sander, a quick spritz of paint and a short buff job and you're ready to go...

wait, OSC makes sanders???? I did not know this.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: obi-wan on 05/30/2014 02:55 am
Autonomous docking and a very empty interior.  Me thinks there won't be a whole lot of difference between Dragon cargo missions and Dragon crew missions.  Anyone think there's a chance you'll see a mix of cargo and crew in the pressurized section?

I think that's a sign this is really far from being ready to carry crew to orbit. A general rule of thumb for launch and entry vehicles is that the habitable volume (volume the crew can move through) is generally about half of the pressurized volume. I suspect most or all of the life support systems are not installed; absolutely the crew stowage items are not in there (although it looks like there are a couple of stowage lockers in the interior "steps" down into the spacecraft.) Also wish there had been some clear shots of the lower three seats - or maybe there was, Livestream crapped out on me just when Elon opened the door. Would also have liked to see people in the seats in launch and entry suits - that will take up a lot of the "free" space!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/30/2014 02:56 am
Nice but the inside silvering is a bit too bright for my liking and possibly reflective so may interfere with instrumentation, sight, etc.  Wonder if they'll keep it or change to something a little less intense.  Actually prefer the Boeing interior in this regard.
Sorry but we have to be honest.
Cheers.

No, what we were seeing was the bare isogrid structure. That would all be covered with padding/insulation.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: randomly on 05/30/2014 02:57 am
I expect the isogrid interior will eventually be covered up with some thermal insulation.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Hauerg on 05/30/2014 02:57 am
Nice but the inside silvering is a bit too bright for my liking and possibly reflective so may interfere with instrumentation, sight, etc.  Wonder if they'll keep it or change to something a little less intense.  Actually prefer the Boeing interior in this regard.
Sorry but we have to be honest.
Cheers.
This is real hardware. Not a mockup of the interior. And it is not finished. So you see the bare pressure hull.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 02:57 am
Autonomous docking and a very empty interior.  Me thinks there won't be a whole lot of difference between Dragon cargo missions and Dragon crew missions.  Anyone think there's a chance you'll see a mix of cargo and crew in the pressurized section?

I think that's a sign this is really far from being ready to carry crew to orbit. A general rule of thumb for launch and entry vehicles is that the habitable volume (volume the crew can move through) is generally about half of the pressurized volume. I suspect most or all of the life support systems are not installed; absolutely the crew stowage items are not in there (although it looks like there are a couple of stowage lockers in the interior "steps" down into the spacecraft.) Also wish there had been some clear shots of the lower three seats - or maybe there was, Livestream crapped out on me just when Elon opened the door. Would also have liked to see people in the seats in launch and entry suits - that will take up a lot of the "free" space!

Only saw four seats, I was also wondering where the other three would go. I always thought is was three in "front" and four "behind" but it could be the other way around.

Pretty sure the interior has a lot of "finalizing" to go yet. There seems to be about a third of that "space" in the animation.

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: luinil on 05/30/2014 02:58 am
If my count is right, it has 5 windows ?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 05/30/2014 02:58 am
My crappy Samsung TV web browser started throwing gobs of green MPEG artifacts and I almost had a nervous breakdown trying to envision the transport stream.  :o
I'm a little late to the party, but...

Best NSF inside joke yet. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 02:59 am
I don't get the fins.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 03:00 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.

Mine as well.  Nothing new.
"That's right folks, nothing new to see here. Move along please."
Perfect delay; the old guard DC folks would grow impatient and go to bed.
I wonder how Michael Gass can compete, and what noises we'll hear from ULA?
Modern manufacturing methodology best practices; made in the USA.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kraisee on 05/30/2014 03:00 am
As trampolines go, this one makes the Soyuz look like it's half a century out of date.

Oh wait...

Ross.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dorkmo on 05/30/2014 03:00 am
is the diameter the same? it feels wider just looking at it but I cant tell?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 03:00 am
20th Century spacecraft landing:

(http://upload.wikimedia.org/wikipedia/commons/9/9a/Soyuz_TMA-2_after_landing.jpg)

21st Century spacecraft landing:

(http://rimstar.org/space/misc/spacex_20110929-dragon-landing-l.jpg)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dcporter on 05/30/2014 03:00 am
I don't get the fins.

Stabilization during abort, is the speculation I've heard hereabouts.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mikelepage on 05/30/2014 03:01 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: luinil on 05/30/2014 03:02 am
I don't get the fins.

someone answered this before but we believe the fins are here to stabilize the dragon in launch escape scenario.
They are believed to also double as radiators.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 03:02 am
I don't get the fins.


I figure they're either for stabilization during launch about or else radiators, since the solar cells are on the trunk.


Maybe both?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Micahgtb on 05/30/2014 03:02 am
Why the flip-top nose?  What purpose does it serve except ascending aerodynamics?

1 less thing to throw away.  Re-usability is the whole point.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: hrissan on 05/30/2014 03:02 am
I don't get the fins.
Search for pictures of MLAS in google...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 03:03 am
20th Century spacecraft landing:

(http://upload.wikimedia.org/wikipedia/commons/9/9a/Soyuz_TMA-2_after_landing.jpg)

21st Century spacecraft landing:

(http://rimstar.org/space/misc/spacex_20110929-dragon-landing-l.jpg)

Where i am from, we have a saying. Don't sh*t in the old well, before the new one is ready and full of crystal clear water.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kraisee on 05/30/2014 03:04 am
I don't get the fins.

Probably there to improve aerodynamic stability during (some?) launch aborts.

There are some situations where the capsule may need the extra stability, perhaps around max-q.   I would imagine some abort modes would pull the trunk with it, and others might leave it behind.

Ross.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dcporter on 05/30/2014 03:04 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.

Reasonably sure I saw four legs in an early low shot…
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: luinil on 05/30/2014 03:04 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.

when they show the side view we can see the 4 legs.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: enkarha on 05/30/2014 03:04 am
Only saw four seats, I was also wondering where the other three would go. I always thought is was three in "front" and four "behind" but it could be the other way around.

Pretty sure the interior has a lot of "finalizing" to go yet. There seems to be about a third of that "space" in the animation.

Randy
Lower seats visible in bottom right corner of the first pic in this post: http://forum.nasaspaceflight.com/index.php?topic=34841.msg1206522#msg1206522
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Cinder on 05/30/2014 03:05 am
I'm no rocket plumber, and it's just a CGI model for PR, but that looks really compact for radiator hardware.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 03:06 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.
Dragons have two legs and two arms-sheesh.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mikelepage on 05/30/2014 03:09 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.

when they show the side view we can see the 4 legs.

Gah.  I should stop making observations when still half asleep.  4 legs (the rear two are close together), 5 windows.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Nilof on 05/30/2014 03:11 am
The main thing I noticed was what looks like a 3D mouse at the center of the panel, which I guess is for rotation and translation controls. That's a rather different setup compared to the twin joysticks you see in most other spacecraft.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 03:11 am
I don't get the fins.

Soyuz has gridded fins. They had to go one better.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 03:11 am
I don't get the fins.

They appease the spirit of Von Braun.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sanman on 05/30/2014 03:11 am
http://i.imgur.com/ZgTUqHY.png
http://i.imgur.com/yCCavFR.png
http://i.imgur.com/nJR1RY0.png
http://i.imgur.com/iLZq0lB.png\

Edit: Attach, don't embed.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: fdasun on 05/30/2014 03:12 am
What a show ! The concept -- no, a real product -- was far beyond my expectation !

In case I missed something critical -- does Dragon V2 have a parachute ? or it will totally rely on reaction thrusters during  its whole descent journey ? I cannot believe it ...

Sounds the redundancy (of reaction thrusters) is encouraging. If I remembered correctly, Musk said it can safely land with 2 thrusters failed ... Whether it is enough or not, I'm still hesitant to make my judgement
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Darkseraph on 05/30/2014 03:13 am
20th Century spacecraft landing:

(http://upload.wikimedia.org/wikipedia/commons/9/9a/Soyuz_TMA-2_after_landing.jpg)

21st Century spacecraft landing:

(http://rimstar.org/space/misc/spacex_20110929-dragon-landing-l.jpg)

20th Century Spacecraft land in the real life. 21st Century Spacecraft land in CGI..... :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 05/30/2014 03:13 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.

Mine as well.  Nothing new.
Ho hum. Just your run of the mill, 7 seater, propulsively landed, reusable spacecraft.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 05/30/2014 03:13 am
I'm no rocket plumber, and it's just a CGI model for PR, but that looks really compact for radiator hardware.
Well, the new trunk looks a little longer than the current trunk, and on the current (old) trunk the radiator is just on the trunk surface, no deploying. It's a design that makes sense. Fins make sense, too for abort stability.

But yeah, I wonder if they could do without a trunk altogether (or a very, very tiny fairing thing) after operational experience is up and they end up doing short, quick rendezvous with a Bigelow space station or something. Could put the radiators in the noze cone if they didn't want to rely on sublimators or whatever (maybe even solar arrays, too, like the old old Dragon design). But anyway, now I'm just speculating.


...I am looking forward to seeing this for the abort tests. Hopefully they can get to both this year. Can't trust the geopolitical situation to get any better...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 05/30/2014 03:14 am
At a certain altitude there is a check event for the super dracos. If they do not pass, chutes deploy.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 03:15 am
Third picture in sanman's post (http://forum.nasaspaceflight.com/index.php?topic=34828.msg1206654#msg1206654); trunk that long and that empty is a fin by itself.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 03:17 am
20th Century Spacecraft land in the real life. 21st Century Spacecraft land in CGI..... :P

As long as they turn off interlacing and turn on MPEG error correction, we'll have real life video soon enough.  :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Nilof on 05/30/2014 03:18 am
Third picture in sanman's post (http://forum.nasaspaceflight.com/index.php?topic=34828.msg1206654#msg1206654); trunk that long and that empty is a fin by itself.

Yes, but it won't kill rotation along the long axis.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 03:18 am
20th Century Spacecraft land in the real life. 21st Century Spacecraft land in CGI..... :P

The 20th century one has a three-barrel combo shotgun/shovel/machete with three types of ammunition : rifle bullets, shotgun shells and flares, to fend off angry bears.
The new one has touch screen though ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/30/2014 03:20 am
I guess those solar panels don't mind the beating they might get during launch. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rickl on 05/30/2014 03:20 am
In case I missed something critical -- does Dragon V2 have a parachute ? or it will totally rely on reaction thrusters during  its whole descent journey ? I cannot believe it ...


Yes, he mentioned that it will have parachutes as backup if the Super Dracos are not working properly during landing.


In addition, the Super Dracos are also the launch abort system, and if they need to be used for that purpose, then it will land in the ocean with parachutes.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 03:20 am
Regarding the fins, common assumption is that they're for stability during abort, as has been mentioned a few times. Allow me to present (with permission) my dragon abort concept diagrams that I made once the fins were confirmed in L2...


L2: We see it all, we know it all.


(not to scale :p)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: enkarha on 05/30/2014 03:21 am
One observation- the controls may be positioned in a way that's handedness-agnostic, with the pilot sitting in either of the front & center seats. Good news for future southpaw astronauts. Also, since Elon is right handed, he may have sat in the wrong seat when he said he was sitting in the pilot's position.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mhlas7 on 05/30/2014 03:21 am
do touch screens work if your wearing gloves? :P

That depends on what type of touch screen is being used

Capacitive touch screens which are used in most smartphones and tablets are activated by an electric conductor such as your finger or a stylus. This is why you see touch screen gloves that essentially allow the conductivity of your finger to go through the glove.

Resistive touch screens have two layers and when they come into contact by something, such as your finger or a pen, pushing them together, the surface is activated. This technology is most commonly used in places where durability and cost are a factor.

I would think that SpaceX would go with resistive touch screens because of their durability and their use without gloves. The avation industry is beginning to certify resistive single touch displays such as the upgraded Rockwell Collins’ Pro Line Fusion flight deck for use in airplanes around 2018. These displays are also designed to avoid inadvertant touching by requiring more pressure to be applied for activation.

http://en.wikipedia.org/wiki/Touch_screen#Technologies
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/30/2014 03:22 am
So...when's the down-select?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 03:22 am
20th Century spacecraft landing:

(http://upload.wikimedia.org/wikipedia/commons/9/9a/Soyuz_TMA-2_after_landing.jpg)

21st Century spacecraft landing:

(http://rimstar.org/space/misc/spacex_20110929-dragon-landing-l.jpg)

Got my new avatar, thanks :)

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Darkseraph on 05/30/2014 03:23 am
I guess those solar panels don't mind the beating they might get during launch.

Surprised they went with solar panels at all and didn't just use a battery. Its not like this craft goes anywhere else but to a station/module.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mlindner on 05/30/2014 03:25 am

No switch guards on the panels, as noted earlier.  I wouldn't want to have my fingers near those buttons during launch or reentry.

They have several astronauts in their employment. Things like that will get added later.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Pete on 05/30/2014 03:27 am
So I'll be the first to do the obligatory photoshop. ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jongoff on 05/30/2014 03:27 am
I guess those solar panels don't mind the beating they might get during launch.

Surprised they went with solar panels at all and didn't just use a battery. Its not like this craft goes anywhere else but to a station/module.

That may not always be the case.

~Jon
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: beancounter on 05/30/2014 03:28 am
Nice but the inside silvering is a bit too bright for my liking and possibly reflective so may interfere with instrumentation, sight, etc.  Wonder if they'll keep it or change to something a little less intense.  Actually prefer the Boeing interior in this regard.
Sorry but we have to be honest.
Cheers.

If you watch the video the interior of the pressure vessel is covered unlike what was on stage.

Ah, thanks, hadn't got to that.  I'll do it before more comments.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 05/30/2014 03:28 am
I guess those solar panels don't mind the beating they might get during launch.

Surprised they went with solar panels at all and didn't just use a battery. Its not like this craft goes anywhere else but to a station/module.
Putting solar cells on the trunk is relatively cheap, doesn't cost you anything in terms of reliability since there's not an extra deployment event, and it buys you more time on orbit to trouble-shoot problems or do other missions. CST-100 recently switched to solar cells on the service module.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 03:28 am
[party thread]
Now I get it. In abort the trunk is pulled too to reduce g forces so that touch screen won't become face screen.
[/party thread]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 03:29 am
20th Century Spacecraft land in the real life. 21st Century Spacecraft land in CGI..... :P

The 20th century one has a three-barrel combo shotgun/shovel/machete with three types of ammunition : rifle bullets, shotgun shells and flares, to fend off angry bears.
The new one has touch screen though ;)

It should also be remembered that said "20th Century Spaceship" NEEDS that gun because 2/3rds of the time it doesn't come down where it was SUPPOSED to so the very real possibility is that gun will be in fact NEEDED :)

(Of course to be honest the other third of the time even if it DOES come down when and where its supposed to there is a good chance the territory won't belong to the right people at the time and that gun might still come in handy! ;) )

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 05/30/2014 03:32 am
Y solar cells only on one side. Doesn't that mean a need to orient the ship more often than if they just warped the thing. Spend more on cells to save on fuel

I'm more worried about solar cells being exposed to hypersonic airflows. Hope they use really good glue. Maybe there's more to the trunk than we've seen so far?

There is definitely more to the trunk than we saw in the unveil tonight!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 03:34 am
I find it interesting that they have changed the iso-grid machined elements of the pressurized structure from what they use for Dragon 1. The new pattern appears to be some kind of iso-grid/hexa-grid hybrid.

1st image - Dragon 1 pattern.
2nd image - Dragon 2 pattern.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mikelepage on 05/30/2014 03:37 am
do touch screens work if your wearing gloves? :P

That depends on what type of touch screen is being used

Capacitive touch screens which are used in most smartphones and tablets are activated by an electric conductor such as your finger or a stylus. This is why you see touch screen gloves that essentially allow the conductivity of your finger to go through the glove.

Resistive touch screens have two layers and when they come into contact by something, such as your finger or a pen, pushing them together, the surface is activated. This technology is most commonly used in places where durability and cost are a factor.

I would think that SpaceX would go with resistive touch screens because of their durability and their use without gloves. The avation industry is beginning to certify resistive single touch displays such as the upgraded Rockwell Collins’ Pro Line Fusion flight deck for use in airplanes around 2018. These displays are also designed to avoid inadvertant touching by requiring more pressure to be applied for activation.

http://en.wikipedia.org/wiki/Touch_screen#Technologies

I can't help but think that the "actual flight hardware" part referred to all the rocketry side of things - that control panel seemed like it was just 4x model S dashboard touchscreen panels integrated into a new shell and given some new software.  Also, I would think that during ascent and landing (when astronauts would be wearing pressure suits) the screens would be almost if not entirely for display purposes only. Otherwise it would be like trying to use a touchscreen while riding a roller coaster = hard to be accurate.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/30/2014 03:41 am
OK Boeing, your move.  8)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/30/2014 03:44 am
I don't get the fins.

They appease the spirit of Von Braun.
And Heinlein :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Darkseraph on 05/30/2014 03:44 am
They didn't really say anything about what the life support system is or how long this can last in orbit independently with a crew.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jdeshetler on 05/30/2014 03:44 am
So I'll be the first to do the obligatory photoshop. ;)

Looks like there is a LED string around each window ports to light up the cabin?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dglow on 05/30/2014 03:47 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.

Mine as well.  Nothing new.
Ho hum. Just your run of the mill, 7 seater, propulsively landed, reusable spacecraft.

Hey, mme, nobody's questioning the spacecraft itself. It's incredible. Some of us would have liked to learn a bit more about it, that's all.

The discussions on this site are fueled off information, and there's nothing better than that which arrives straight from the horse's mouth, so to speak. I wish Elon had shared more detail regarding this amazing piece of work.

The more info we receive directly from SpaceX, less speculation takes place. And less speculation leads to a higher SNR here on NSF. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mlindner on 05/30/2014 03:50 am
So I'll be the first to do the obligatory photoshop. ;)

Looks like there is a LED string around each window ports to light up the cabin?

That's just the outer hull, LEDs wouldn't be there. That's likely just reflection by the corners acting like corner reflectors to any camera light.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/30/2014 03:51 am
I guess those solar panels don't mind the beating they might get during launch.

It's not like they're going to get covered by dirty water during launch...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dcporter on 05/30/2014 03:52 am
They didn't really say anything about what the life support system is or how long this can last in orbit independently with a crew.

A couple days IIRC?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dglow on 05/30/2014 03:54 am
They didn't really say anything about what the life support system is or how long this can last in orbit independently with a crew.

A couple days IIRC?

The exact number of days will be dependent upon the size of the crew.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lar on 05/30/2014 03:57 am
The discussions on this site are fueled off information, and there's nothing better than that which arrives straight from the horse's mouth, so to speak. I wish Elon had shared more detail regarding this amazing piece of work.

I imagine so do... Boeing... the Chinese... Roscosmos...  etc.

I'm cool with what we got.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Falcon8 on 05/30/2014 04:00 am
So I'll be the first to do the obligatory photoshop. ;)

Can you do one with Kerbal Space Program on one of the screens?  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 04:02 am
So I'll be the first to do the obligatory photoshop. ;)

Can you do one with Kerbal Space Program on one of the screens?  ;D

if you're going too slow i feel bad for you son i got 99 boosters all in stage 1
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: su27k on 05/30/2014 04:05 am
The more info we receive directly from SpaceX, less speculation takes place. And less speculation leads to a higher SNR here on NSF.

He spent some time answering media questions afterwards, we just didn't get to see/hear it. And media people is going inside Dragon V2 right now, so we may get more details tomorrow.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: tman5005 on 05/30/2014 04:05 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.
Dragons have two legs and two arms-sheesh.

Dragons have one beefy arm.

See Trogdor the Burninator.

http://www.youtube.com/watch?v=90X5NJleYJQ
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jongoff on 05/30/2014 04:09 am
Very cool - It looks more like a mockup than I expected - but understandably. It is a work in progress.

Did anyone else notice it only had two landing legs? That's why we didn't go around the back.
Dragons have two legs and two arms-sheesh.

Dragons have one beefy arm.

See Trogdor the Burninator.

http://www.youtube.com/watch?v=90X5NJleYJQ

I definitely agree it would've been even cooler with a proper TROGDOR arm on it. I'll probably never get paid to build them one, but I wish we had the kind of free cash to just build one for funsies.

~Jon
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 05/30/2014 04:32 am
Some observations:

It looks like there is solar cells on only one side of the trunk. The radiators could either be on the other side or in the fins (or maybe (but probably unlikely) they have found a way to integrate them in the capsule despite the backshell TPS (Still SPAM?)).

There would not be fins if it were nor for aerodynamic reasons -- i.e. abort stability, but once they were included they might double as radiators as well. The trunk would probably be released after drogue deploy to avoid the chance of hitting the capsule (they hopefully learned from the recontact incident that doomed F1#3).

I am surprised the nose door does not open farther in the video. I think this should be fixed in the real one since otherwise it would put too much limitations on docking port design on space stations etc, and for vehicle to vehicle crew rescue.

edit: added: Also there is no reason to exclude the possibility that there is enough battery capacity in the Dragon V2 so that the solar cells could be optional for space station flights, as long as limited margins for docking re-tries, etc. is accepted.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: dglow on 05/30/2014 04:36 am
The discussions on this site are fueled off information, and there's nothing better than that which arrives straight from the horse's mouth, so to speak. I wish Elon had shared more detail regarding this amazing piece of work.

I imagine so do... Boeing... the Chinese... Roscosmos...  etc.

I'm cool with what we got.

Certainly, Lar. But indulge me a few examples, however trivial:

1. There wasn't a mention of the fins on the trunk. Yet they're entirely new for D2, and they look kinda cool. Why not point them out to the public? What would the act of doing so have told the Chinese?

2. Elon hops into a capsule that clearly has one row of seats, having just claimed it can seat seven. How about a simple: "Check it out, our seating configuration is flexible. We thought of that, look at us."

3. Sweet leather chairs, as seen in the teaser image on SpaceX.com. Elon, were they designed by your boys at Telsa? No idea. Not a word about them.


Guys, I'm not bashing SpaceX here. I wish Elon's presentation had tooted SpaceX's horn even more. They are in, what seems to me, a delicate time what with CCiCap down-select on the horizon, and of course the ULA lawsuit.

I just want this company to put its best foot forward.   :-\
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JohnGN on 05/30/2014 04:38 am
Did anyone notice that (on the animation) the dragon's docking port retracts before the nose cone closes back up again.  (happens just as it undocks from station).  It would help with clearance between dragon and ISS.  But would also add complexity.  Question: if the tunnel is long enough when extended, could it also be used for EVA?

John

(1st post, hope its worth it)

Nuts.  On 2nd look, its just the docking adapter ring retracting.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Seattle Dave on 05/30/2014 04:38 am
Great article by Chris!
http://www.nasaspaceflight.com/2014/05/spacex-lifts-the-lid-dragon-v2-crew-spacecraft/
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 04:40 am
FWIW, the capsule had a second row of seats - the inside camera caught their front edges in some shots.

As for the rest, IMO he just forgot some of the stuff.  He wasn't reading a script, this was not very rehearsed, he was just explaining as he went along, and I think after he walked off stage he want "Facepalm...  the Fins, the seats".
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CriX on 05/30/2014 05:04 am
I wonder what the acoustic experience will be like on the inside during descent with all those superdracos firing.  Sheesh!  Pretty neat how they wrapped the PICA up to protect against the superdracos exhaust.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: swervin on 05/30/2014 05:04 am
Another pic from Jeff Foust:

http://t.co/zKZIiRc89x

I hope some of the media take more pics of the interior and not just the flashing control panel -- which is totally BA, for the record!! :-)

Splinter
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TSomers on 05/30/2014 05:17 am
I attached the original size picture of the interface from Jeff Foust. 

It looks like it's mostly just a mockup of a possible interface, but I wonder if someone with more experience could find anything of interest in the "Life Support Valves Schematic" section. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 05/30/2014 05:25 am
To expand on what I said about fins in my previous message:

The fins are probably there mainly because of aerodynamic reasons (as for MLAS) -- use as cooling fins are not the most likely reason because
   (a) there is solar cells on only one side of the trunk and the other side would be a thermally better placement than fins
   (b) the fins would pick up solar heating when not either edge-on or on the opposite side of the trunk -- defeating the cooling
   (c) the fins are rather small for efficiently dissipating heat, especially since only 1 of the 4 would be effective at any time per (b)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: malu5531 on 05/30/2014 05:34 am
Forbes has an article (http://www.forbes.com/sites/alexknapp/2014/05/29/spacex-unveils-its-new-dragon-spacecraft/) with a clear view of all seven seats.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jarnis on 05/30/2014 06:01 am
One observation- the controls may be positioned in a way that's handedness-agnostic, with the pilot sitting in either of the front & center seats. Good news for future southpaw astronauts. Also, since Elon is right handed, he may have sat in the wrong seat when he said he was sitting in the pilot's position.

Airbus jets have sidesticks - left seat has the stick on the left side, right seat has the stick on the right side - and reportedly pilots say it is surprisingly easy to fly either way.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: flymetothemoon on 05/30/2014 06:06 am
Knew I'd seen it before. Elon's only gone and made Fireball XL-5 Jr.!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: flymetothemoon on 05/30/2014 06:09 am
Fireball XL5 is clearly the secret love child of Skylon and Dragon v2. Skylon XL5!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/30/2014 06:30 am
Purely FWIW, I suspect that the fins will go the way of their counterparts around the base of the Falcon-9 core.

That aside, everything about this design shouts "reusable orbital taxi" to me. I doubt now that there will be an 'exploration' version of Dragon v.2 just because the whole thing seems too optimised for the Earth-to-Station run.

It's interesting that the reusable nose-cap has made a return.

One last question - does anyone else consider this a whole new spacecraft? I'm not even sure that the pressure vessel is similar.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/30/2014 06:38 am
I find it interesting that they have changed the iso-grid machined elements of the pressurized structure from what they use for Dragon 1. The new pattern appears to be some kind of iso-grid/hexa-grid hybrid.

1st image - Dragon 1 pattern.
2nd image - Dragon 2 pattern.
Subtle point. Actually it's all isogrid but you have to look for the triangles within triangles.

Those things are stiffners so I'd guess either they found the original structure was too flexible or the loads on the new design are quite a bit higher.

It's debatable if these new panels are actually faster to machine, given they take less metal out.

I'm late to the party (just seen the video) so please forgive me if these have come up before.

There's a lot of stuff to be fitted inside that capsule before it flies. Anyone complaining about the interior decor, it's going be buried under lockers, ECLSS, insulation etc. Isogrid really scores when you want to include "bosses" for bolts and screws to mount to.

Really surprised that those switches have not protective bars to stop people nudging them in free fall, given that I though they had several astronauts looking over the design.

Re-closable nose. It's the details that improve reuse. Like not having to build/fit a new one.

Solar panels on the trunk took me by surprise. I'd guessed they were going to batteries

Super Dracos really are super at 160x Draco thrust. 1000psi chamber pressure is high for pressure feds.
I wonder if they still have a low thrust "vernier" mode to do the job of Draco thrusters as well?

Thruster pods are a lot bigger than previous cgi's showed and much further back.

People may think still carrying parachutes is overkill but the first time a Dragon 2.0 lands with all it's thrusters out on it's 'chutes that decision will be vindicated (and loudly applauded by the survivors  :( )

And now the big new thing.

Who noticed that capsule shape?

People will remember the CGI but look at the live video. The side that Musk enter from is almost flat.

Flattening one side of a cone (or actually lopping off a chunk of it as most people would describe it) is the classic beginnings of a lifting body.

While technically anything with an off axis centre of gravity does a lifting reentry (In the US everything after Mercury) this is quite pronounced.

It's not a Dream Chaser or Bezos grade LB, but it's definitely not a straight cone.  :o

[EDIT. That assumes he's staying with a rear first entry, which the TPS placement seems to confirm. I don't see an end-over-end flip to fly nose first for bigger cross range. I wonder if they're are going for a lifetime TPS good for the whole X flights capsule life? ]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sojourner on 05/30/2014 06:48 am
And now the big new thing.

Who noticed that capsule shape?

It's still the same overall shape. the increased size of the super draco "noses" just give a misleading impression that the capsule is no longer a cone.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 06:53 am

People will remember the CGI but look at the live video. The side that Musk enter from is almost flat.

Flattening one side of a cone (or actually lopping off a chunk of it as most people would describe it) is the classic beginnings of a lifting body.

While technically anything with an off axis centre of gravity does a lifting reentry (In the US everything after Mercury) this is quite pronounced.

It's not a Dream Chaser or Bezos grade LB, but it's definitely not a straight cone.  :o

[EDIT. That assumes he's staying with a rear first entry, which the TPS placement seems to confirm. I don't see an end-over-end flip to fly nose first for bigger cross range. I wonder if they're are going for a lifetime TPS good for the whole X flights capsule life? ]
Are we sure about this?  Could it just be a straight cone with the side protrusions giving that effect?

Can anyone calc the precise size of the thing?  The trunk length is certainly enormous.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Halidon on 05/30/2014 07:06 am
A little sad that the Q+A wasn't webcast along with the presentation, ah well. Otherwise, quite an interesting unveiling. From someone who was expecting "just" V1 with thruster fairings, I was pleasantly surprised.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Helodriver on 05/30/2014 07:08 am
Every party needs cake. SpaceX provided tonight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 07:21 am
Are the fuel tanks just inside the rim of the capsule's heat shield, or are they surrounding the nose?

Awkward in 1G to walk over that big gap in the floor for the extra three seats, especially with the horizontal seating that Musk commented on.  I think those will almost certainly be sacrificed to cargospace on some flights - can an astronaut do that (are the seats reconfigurable in orbit), or would it be down to the manufacturer per-mission, or would 7 seats be a fixed design points across missions?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 05/30/2014 07:27 am
The discussions on this site are fueled off information, and there's nothing better than that which arrives straight from the horse's mouth, so to speak. I wish Elon had shared more detail regarding this amazing piece of work.

I imagine so do... Boeing... the Chinese... Roscosmos...  etc.

I'm cool with what we got.

Certainly, Lar. But indulge me a few examples, however trivial:

1. There wasn't a mention of the fins on the trunk. Yet they're entirely new for D2, and they look kinda cool. Why not point them out to the public? What would the act of doing so have told the Chinese?

2. Elon hops into a capsule that clearly has one row of seats, having just claimed it can seat seven. How about a simple: "Check it out, our seating configuration is flexible. We thought of that, look at us."

3. Sweet leather chairs, as seen in the teaser image on SpaceX.com. Elon, were they designed by your boys at Telsa? No idea. Not a word about them.


Guys, I'm not bashing SpaceX here. I wish Elon's presentation had tooted SpaceX's horn even more. They are in, what seems to me, a delicate time what with CCiCap down-select on the horizon, and of course the ULA lawsuit.

I just want this company to put its best foot forward.   :-\

I think it's about trying to focus the mass media on just a few major points.  The more they tell them at an event like this, the more likely it is the articles will confuse some of the facts or focus on the wrong things.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Helodriver on 05/30/2014 07:30 am
Two rows of seats. Bottom ones are hard to get into. Source: the lump on my head from trying.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: vt_hokie on 05/30/2014 07:31 am
I'll admit, I never expected propulsive landings to actually make it into the CCDev vehicle, but I like being proven wrong.  That is pretty cool!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Halidon on 05/30/2014 07:40 am
Two rows of seats. Bottom ones are hard to get into. Source: the lump on my head from trying.
Helmets: not just for show  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TrevorMonty on 05/30/2014 07:55 am
First manned flight ( summer 16  + usual Spacex delay) will be about same time as DC ( Nov16).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 08:01 am
Solar panels on the trunk took me by surprise. I'd guessed they were going to batteries
I think those are only complementary for the battery pack. They don't have enough area to supply peak energy to the craft, just to keep topping up the batteries on idle times.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 08:03 am
I'll admit, I never expected propulsive landings to actually make it into the CCDev vehicle, but I like being proven wrong.  That is pretty cool!
They needed a LAS. They wanted an integrated, reusable LAS. So the hardware and fuel is there already. Why not landing with it?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 08:05 am
Awkward in 1G to walk over that big gap in the floor for the extra three seats, especially with the horizontal seating that Musk commented on.  I think those will almost certainly be sacrificed to cargospace on some flights - can an astronaut do that (are the seats reconfigurable in orbit), or would it be down to the manufacturer per-mission, or would 7 seats be a fixed design points across missions?
I doubt Nasa will use the 7 seats regularly. 4 is more likely. In any case, from what I've read, there should be room/weight budget for 500Kg of cargo inside the capsule. Probably that "gap" will be filled with cargo.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Dr. Strangelove on 05/30/2014 08:12 am
Maybe it's an optical illusion, but the diameter on Dragon V2 seems larger. Also, is this meant to launch of F9 or Heavy ?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/30/2014 08:14 am
A little sad that the Q+A wasn't webcast along with the presentation, ah well.

There was a Q&A? I'm not talking about the off-stage one-on-one interactions... but someone from SpaceX officially answering questions.

A few thoughts on the things that did see though.

I think a benefit of the retractable nose-cap is that you can now move the parachutes out of wherever they're being stored in v1, and put them in the volume between the nose-cap and the docking mechanism. The riser attachment points can run through a tunnel between the outside of the hatch, and the exterior, and connect to the pressure vessel. Contiguous operational pressurised volume increases.

The solar panels on the body of the trunk are interesting. Having them as depicted in the animation removes a requirement for deployment. As for thermal control, I think an undocked v2 can use a barbecue roll for thermal management? And a docked v2 would use the ECLSS of ISS. But in their current config, these cells are exposed to airflow (in all regimes) during ascent. Could there be a retractable cover? Either something that's not shown - like fold out spoilers; or a sliding door - which slides over/under/into the other half of the trunk? Also, the trunk itself isn't much more than a tube though is it? Why can't the trunk itself be made of two pieces, that then fold out (on hinges attached to the exterior of the capsule)?

Relatedly, how is the trunk made re-usable? It was depicted as detaching from the crew/cargo compartment. Does it have its own heat shield?

Finally, it's pretty interesting to note the differences(if any) between when "Old Space"/"New Space"/ and NASA (to make it a fair comparison - talking only about SLS/Orion) make "an event" of something - in terms of the flight readiness of the hardware that they're showing off. Not the release of information and news to the public, but events with first hand access. Even if they would be open to doing so, I think only SpaceX's ~all-in-house-manufacturing, and launch cadence, enables it? On the other hand, there's always something "new" at a NASA centre..?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 08:15 am
Maybe it's an optical illusion, but the diameter on Dragon V2 seems larger. Also, is this meant to launch of F9 or Heavy ?
F9 is more than enough for a ISS trip.

FH would only be required for a moon Apollo 8 trip, but Dragon v2 itself is probably not suitable for BEO, at least on the first iteration.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 08:20 am
As for thermal control, I think an undocked v2 can use a barbecue roll for thermal management? And a docked v2 would use the ECLSS of ISS.
One thing that intrigues me is that while the solar panels only cover half the trunk, they are not symmetrical, they are on the same side. That probably means that side will be facing the sun while the other radiates.

Relatedly, how is the trunk made re-usable? It was depicted as detaching from the crew/cargo compartment. Does it have its own heat shield?
Without the expensive extendable solar panels, the trunk is very inexpensive, no need to make it re-usable.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Linze on 05/30/2014 08:30 am

There was a Q&A?

Yes, multiple news reports say Musk answered detailed questions for about half an hour.

Haven't found any run down yet.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 08:32 am
20th Century spacecraft landing:

(http://upload.wikimedia.org/wikipedia/commons/9/9a/Soyuz_TMA-2_after_landing.jpg)

21st Century spacecraft landing:

(http://rimstar.org/space/misc/spacex_20110929-dragon-landing-l.jpg)

20th Century Spacecraft land in the real life. 21st Century Spacecraft land in CGI..... :P
You just knew I was going to add one more... ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IslandPlaya on 05/30/2014 08:41 am
I thought Elon's presentation was honest and refreshing. He doesn't have to pander to share holders and so I don't think he rehearsed his speech unlike Mr Cook from Apple would do..
Sure, sitting in an NSF armchair it is easy to point out negatives. Can you honestly say you would have done better?
The reveal just confirms that Elon is my fave billionaire!
Am I amazing people?
Hell yes!
Go SpaceX!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 08:47 am
Congrats on the roll-out SpaceX... 8) Now let's get her up on orbit ASAP! :)

She's a beauty for a capsule... BTW I do see a "baby" DC-X... ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Darkseraph on 05/30/2014 08:54 am


You just knew I was going to add one more... ;D

Ehhh judging by how the Dreamchaser last "landed"...I'm going to take a pass on that vehicle!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 09:10 am
As for thermal control, I think an undocked v2 can use a barbecue roll for thermal management? And a docked v2 would use the ECLSS of ISS.
One thing that intrigues me is that while the solar panels only cover half the trunk, they are not symmetrical, they are on the same side. That probably means that side will be facing the sun while the other radiates.

Relatedly, how is the trunk made re-usable? It was depicted as detaching from the crew/cargo compartment. Does it have its own heat shield?
Without the expensive extendable solar panels, the trunk is very inexpensive, no need to make it re-usable.

Ahh, so it's the *mechanism* that makes non-multijunction space solar panels so pricy.  This explains a lot.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 09:12 am


You just knew I was going to add one more... ;D

Ehhh judging by how the Dreamchaser last "landed"...I'm going to take a pass on that vehicle!

I thought landing on its nose would be a huge deal, but apparently in the course of normal planned operations, the bottom of that nose actually separates and bends down to act as a skid plate landing gear, rather than using a wheel in front, so that's all structurally reinforced in the first place.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 09:14 am


You just knew I was going to add one more... ;D

Ehhh judging by how the Dreamchaser last "landed"...I'm going to take a pass on that vehicle!
Hey, not nice... It's a party thread! Go Dragon!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: HarbingerDawn on 05/30/2014 09:48 am
Ehhh judging by how the Dreamchaser last "landed"...I'm going to take a pass on that vehicle!

Those weren't flight-design landing gears, so I don't think we should judge. But this is getting off-topic for a SpaceX thread :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/30/2014 09:56 am
Another thought: I suspect that the conformal solar arrays will make it, but I wouldn't be surprised if the first few flights used a Cargo Dragon-style 'solar wing' just to meet schedule. There will then be a conflict between 'working model' and 'intended final design'.

It also wouldn't surprise me if the technical challenges for the reusable nose cap lead it to be deferred and ultimately cancelled. The hinged nose cap was always intended to be part of the design (the earliest variant of the Dragon design had the solar arrays fold into the nose cap so they could be reused too). I suspect the design calls for explosive bolts as emergency releases if the hinge or motor fails and, at a later design review, SpaceX may conclude that it is simpler just to have the explosive release bolts to save weight.

It's probably an issue of me being brought up with Apollo heritage designs but that control console (very Star Trek - TNG, for what it's worth) just doesn't 'feel' robust enough for me. I know that the current design assumption for all the CCTs and Orion too is that the flight computer will handle the vast majority of manoeuvres either automatically or in response to a push-button/touch-screen control input. However, it just looks like too much reliance has been placed on the touch screen system whose long-term response to space thermal and radiation environments is probably imperfectly understood.

I'm guessing that the manual stick is a three-axis controller.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jabe on 05/30/2014 10:54 am
curious.. was there a life support system view-able in the cabin..it has to be of reasonable size so it should be hidden..
jb
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/30/2014 10:56 am
Solar panels on the trunk took me by surprise. I'd guessed they were going to batteries
I think those are only complementary for the battery pack. They don't have enough area to supply peak energy to the craft, just to keep topping up the batteries on idle times.
Agreed. AFAIK the trunk remains expendable so I'm guessing they won't be top of the line triple junction cells given they will be discarded. Fixed mounting also eliminates the complex (IE expensive ) protective door and deployment mechanisms. All good from a cost PoV and I guess the weight trade works out pretty well (I wonder where the batteries are. They're likely to be fairly heavy but reusing them would be nice, so putting them at least partly in the capsule seems the way to go)  :)

Now making the it come back with the trunk still attached would be astonishing, but I just don't think it's possible.

I'll admit, I never expected propulsive landings to actually make it into the CCDev vehicle, but I like being proven wrong.  That is pretty cool!
They needed a LAS. They wanted an integrated, reusable LAS. So the hardware and fuel is there already. Why not landing with it?
Once you realize that the same fuel can be used in different flight phases which are completely exclusive (emergency and normal) and you're going to re-use the thrusters every capsule flight (letting you fine tune the design) it's obvious.

Except of course that no one seems to have thought of it before.  :(

But making it work (especially ensuring it fail safes to "emergency" thrust level" is where it gets really tricky.

Ahh, so it's the *mechanism* that makes non-multijunction space solar panels so pricy.  This explains a lot.
So much so that every  year there is a conference on the assorted gadgets that satellites, spacecraft and probes need to take care of all the "little things" in flight. Lookup "Space Mechanisms" conference.

Building an arm to open a solar panel on Earth is (relatively) simple.

Now imagine at some times the arm weighs 3x it's normal weight and may cycle through a 400c temperature range without seizing up while in a near vacuum. Likewise unlocking and opening the door on the box the arm is mounted in.

Some would find it a fascinating challenge, others a monumental PITA to engineer.  :(

Another thought: I suspect that the conformal solar arrays will make it, but I wouldn't be surprised if the first few flights used a Cargo Dragon-style 'solar wing' just to meet schedule. There will then be a conflict between 'working model' and 'intended final design'.
Which would make it basically a V 1.0 cargo dragon trunk.  :(
Quote
It also wouldn't surprise me if the technical challenges for the reusable nose cap lead it to be deferred and ultimately cancelled. The hinged nose cap was always intended to be part of the design (the earliest variant of the Dragon design had the solar arrays fold into the nose cap so they could be reused too). I suspect the design calls for explosive bolts as emergency releases if the hinge or motor fails and, at a later design review, SpaceX may conclude that it is simpler just to have the explosive release bolts to save weight.
Technical challenges? It does basically what the GNC door did.

If they are playing by NASA rule "Pyrotechnic devices" (of which the Shuttle had 300) can only be installed on the pad. That was 1 week of pad time, along with hypergol loading.

There may be a requirement to jettison the nose in an emergency but I bet Spacex will move heaven and earth to not use explosive bolts and do it some other way, like they did stage separation and AFAIK flight termination.

pyrotechnics <> reusability.  :(
Quote
It's probably an issue of me being brought up with Apollo heritage designs but that control console (very Star Trek - TNG, for what it's worth) just doesn't 'feel' robust enough for me. I know that the current design assumption for all the CCTs and Orion too is that the flight computer will handle the vast majority of manoeuvres either automatically or in response to a push-button/touch-screen control input. However, it just looks like too much reliance has been placed on the touch screen system whose long-term response to space thermal and radiation environments is probably imperfectly understood.
It's a fair point. While Shuttle did have a "glass cockpit" the buttons were around the screen, not on it. IIRC the closest to a "touch screen" Shuttle got was a light pen option (but I'm hazy on that and I'm not sure it was part of the flight controls). Radiation is a concern but I'm putting my money on the long term "gremlin" being vibration, although they won't have the dire environment that 2 1.5 million lb SRB's can cause.
[EDIT Also "Viewable in direct sunlight" takes on a whole new meaning when the sunlight is a bout 1/3 brighter than at the Earth's surface (I'm guessing all those windows will carry sun shades). That said if any data can be displayed on any display then there should be enough redundancy to deal with screen failure. I'd also note that computer wise this those processors are 20 or more times faster than anything that controlled the Shuttle, which was aerodynamically a much more complex vehicle. ]

Again IIRC the Apollo hand controller did have a more-or-less direct connection to the thruster firing circuits.

But in truth 99% of the time the controls will ask the computer to do something, like every US spacecraft since Gemini. Of course
Quote
I'm guessing that the manual stick is a three-axis controller.
Probably.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 05/30/2014 11:09 am
The four LCD displays look remarkably like the center console display from the Tesla.  I wonder if it is the same hardware and underlying UI code.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/30/2014 11:10 am
Are the fuel tanks just inside the rim of the capsule's heat shield, or are they surrounding the nose?

Awkward in 1G to walk over that big gap in the floor for the extra three seats, especially with the horizontal seating that Musk commented on.  I think those will almost certainly be sacrificed to cargospace on some flights - can an astronaut do that (are the seats reconfigurable in orbit), or would it be down to the manufacturer per-mission, or would 7 seats be a fixed design points across missions?

Elon said the propellant tanks would be around the base of the heat shield. And they would have to be due to size/amount required
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 05/30/2014 11:10 am
I'm still wondering about the flip top nosecone. It opens at an exact 180 degree angle in the video. Perhaps it contains the docking radar?

Whoops. I was up late and now see it opens at 90 degrees. Still, I wonder where the docking radar will end up.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 11:18 am
As for thermal control, I think an undocked v2 can use a barbecue roll for thermal management? And a docked v2 would use the ECLSS of ISS.
One thing that intrigues me is that while the solar panels only cover half the trunk, they are not symmetrical, they are on the same side. That probably means that side will be facing the sun while the other radiates.

Relatedly, how is the trunk made re-usable? It was depicted as detaching from the crew/cargo compartment. Does it have its own heat shield?
Without the expensive extendable solar panels, the trunk is very inexpensive, no need to make it re-usable.

Ahh, so it's the *mechanism* that makes non-multijunction space solar panels so pricy.  This explains a lot.
Not only the mechanism. There is a lot less solar panel area with this approach.

They got rid  of:
- Extendable mechanism
- solar panel fairings
- large area of costly solar panels
- a very critical failure point (deploying)
- associated weight
- associated drag
- clearance issues (hypothetical narrow space for docking)

But now they have the following limitations:
- less operation time (7-10 days)
- more battery weight (probably less than the solar panels weight + drag effect)
- craft orientation is not independent of power output
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Dave G on 05/30/2014 11:24 am
It's probably an issue of me being brought up with Apollo heritage designs but that control console (very Star Trek - TNG, for what it's worth) just doesn't 'feel' robust enough for me. I know that the current design assumption for all the CCTs and Orion too is that the flight computer will handle the vast majority of manoeuvres either automatically or in response to a push-button/touch-screen control input. However, it just looks like too much reliance has been placed on the touch screen system whose long-term response to space thermal and radiation environments is probably imperfectly understood.

The center panel is all manual switches.  Also, there are 4 touch screens, which seems like a lot of redundancy.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Dave G on 05/30/2014 11:30 am
There is a lot less solar panel area with this approach.

Are you sure?  The new trunk looks longer, and seems to be covered entirely on one side.  Has anyone done the math on this?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/30/2014 11:31 am
emergency releases if the hinge or motor fails and, at a later design review, SpaceX may conclude that it is simpler just to have the explosive release bolts to save weight.

And what about a rope or mechanism with which a crew member can close it manually?
Just joking :D ... though some manual mechanism is not so mad thing maybe - what do you think?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: darkenfast on 05/30/2014 11:32 am
A couple of observations I'd like to throw out based on what we've seen so far.  First, some have noted how open or empty the interior is. While it wouldn't surprise me to see insulation, paneling, boxes of gear and such make their appearance, do remember that the bulk of the environmental equipment will probably go under the deck.  There is a shallow cylindrical space, about 6 1/2 to 7 feet in diameter and about 2 feet deep under there.  Second, I would like to find out more about these conveniently sci-fi looking fins on the trunk.  Is the trunk really going to stay attached for part of an abort?  If they are for radiators, why do they have to be moved from where they are in the current Dragon?  More heat being produced?   I was really surprised at the windows.  I half expected few or none, with the role filled by cameras and screens.  What would make the oval shape worth it?  Speaking of which, what happened to the requirement for direct vision during docking?  The folding control screen is very nice.  I seem to remember that the Russians have shown the same folding arrangement on their Next-Gen Spacecraft.  I'll bet the seats change some before this thing flies. 

Overall, a very intriguing spacecraft.  I would love to know what delayed the announcement, and if it was related to the short running time. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/30/2014 11:43 am
curious.. was there a life support system view-able in the cabin..it has to be of reasonable size so it should be hidden..

I'd always assumed that the bulk of the ECLSS would be in either the lower or upper service bays, outside of the pressure vessel. Thinking about it, though, doesn't make sense as that would make maintenance unnecessarily difficult. An alternative would be to put the mechanisms in at the bottom of the pressure vessel, just behind the rear row of seats.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 05/30/2014 11:48 am
What are these thingies at the top of the trunk. 6 around the edges 4 sqarish one in the center and some small ones. I think they are new for V2, except maybe some of the small ones.

Some may be additional batteries to supplement those in the capsule, but that does not account for all.

V1 had little avionics in the trunk.

( Picture captured from the animation by spaceref.com )
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CJ on 05/30/2014 11:52 am
I was very impressed on several levels. The presentation style was low key and unrehearsed; to do otherwise would have given it a sales pitch feel, which is always a bad thing IMHO. I've never seen Elon Musk speak before so I don't know if this is his normal style or not, but I like it.

The one bit of showmanship was the mist around Dragon for the unveiling, which I liked.

The delay in the presentation: I'm just glad it wasn't a scrub.  :P

The ship itself... better than I was expecting, and I was expecting very good things. One thing I thought looked great (though others differ) is the bare inner hull; I thought that looked very, well, spaceshipish. :) I know it's probably going to be covered, but it looks good to me.

One puzzling thing that caught my eye; the outer hull (the white parts of it). It seems seemless, very unlike Dragon 1. Is this even possible, or is this a temporary, non-flight part?

However, on thing makes this very clearly a non-flight-ready SpaceX spacecraft: the cheese compartment hasn't been installed - yet.  :P
 
I do hope a transcript of the Q&A appears at some point; going by what those who saw it have said, it sounds like it was fascinating.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MATTBLAK on 05/30/2014 11:52 am
Fly, my Pretty... ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 11:54 am
What are these thingies at the top of the trunk. 6 around the edges

Those look like tanks. Consumables to extend flight time ... extra propellant ... or something.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 11:55 am
Dragon 2: five stars.

Dragon 2 presentation: two stars.

Completely underwhelming. Elon has never been a 'polished' presenter, but this is disappointing for him. Where's the beef? When you gather the world's attention, you owe a bit more.

My $.02, of course.

Mine as well.  Nothing new.
Ho hum. Just your run of the mill, 7 seater, propulsively landed, reusable spacecraft.

We already knew pretty much everything shown, and propulsive landing only makes sense on planetary bodies lacking a dense atmosphere.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/30/2014 11:57 am
Anywhere mentioning what this thing might weigh, especially at landing? The final deceleration looks quite leisurely, eight SDs going to throttle really deep?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/30/2014 12:06 pm
What are these thingies at the top of the trunk. 6 around the edges

Those look like tanks. Consumables to extend flight time ... extra propellant ... or something.

Given the trunk will be drop before athmospheric reentry that might be extra propellant for the SuperDracos in case of emergency. Just guessing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lar on 05/30/2014 12:09 pm
Certainly, Lar. But indulge me a few examples, however trivial:

1. There wasn't a mention of the fins on the trunk. Yet they're entirely new for D2, and they look kinda cool. Why not point them out to the public? What would the act of doing so have told the Chinese?

2. Elon hops into a capsule that clearly has one row of seats, having just claimed it can seat seven. How about a simple: "Check it out, our seating configuration is flexible. We thought of that, look at us."

3. Sweet leather chairs, as seen in the teaser image on SpaceX.com. Elon, were they designed by your boys at Telsa? No idea. Not a word about them.

Guys, I'm not bashing SpaceX here. I wish Elon's presentation had tooted SpaceX's horn even more. They are in, what seems to me, a delicate time what with CCiCap down-select on the horizon, and of course the ULA lawsuit.

I just want this company to put its best foot forward.   :-\

I think you got some good answers but since you were directly addressing me.
1 - I agree with the "don't confuse the regular media with too much info" theory
2 - pretty definitively has 7 seats, pics confirm it
3 - probably but who cares? See #1

Two rows of seats. Bottom ones are hard to get into. Source: the lump on my head from trying.

I hate you., Helodriver :)  Also, this pretty much sorts #2 above


We already knew pretty much everything shown, and propulsive landing only makes sense on planetary bodies lacking a dense atmosphere.


Seriously? Propulsive landing doesn't make sense on Earth? Because repacking parachutes is a cheap and completely reliable process?  Because throwing away your LAS makes more sense than reusing it? Lee Jay, perhaps nothing will satisfy you.



Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 05/30/2014 12:13 pm
I've never seen Elon Musk speak before so I don't know if this is his normal style or not, but I like it.

It is. (http://shitelonsays.com/transcript/)

I do hope a transcript of the Q&A appears at some point; going by what those who saw it have said, it sounds like it was fascinating.

That'd defeat the point of a press event.

http://www.nbcnews.com/science/space/mars-ahead-spacex-unveils-dragon-v2-capsule-astronaut-trips-n118116

There's a quote from Bob Bigelow and another from Elon at the end.

http://twitter.com/jeff_foust

Jeff has a number of quotes.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/30/2014 12:15 pm
What are these thingies at the top of the trunk. 6 around the edges

Those look like tanks. Consumables to extend flight time ... extra propellant ... or something.

Given the trunk will be drop before athmospheric reentry that might be extra propellant for the SuperDracos in case of emergency. Just guessing.

That would also answer the question why the trunk would stay attached to the dragon during launch escape, besides the fins... if I recall it correctly and would stay attached... :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Star One on 05/30/2014 12:28 pm
This news article claims that Space X & Boeing are more or less neck & neck in the development of their respective capsules.

http://www.theguardian.com/technology/2014/may/30/elon-musk-unveils-dragon-v2-spacecraft-for-seven-astronuants
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 12:29 pm

They got rid  of:
- Extendable mechanism
- solar panel fairings
- large area of costly solar panels
- a very critical failure point (deploying)
- associated weight
- associated drag
- clearance issues (hypothetical narrow space for docking)

But now they have the following limitations:
- less operation time (7-10 days)
- more battery weight (probably less than the solar panels weight + drag effect)
- craft orientation is not independent of power output
Where do these first two limitations spring from?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 12:33 pm
Anywhere mentioning what this thing might weigh, especially at landing? The final deceleration looks quite leisurely, eight SDs going to throttle really deep?

From the last video of the SDs, it looks like they may have pulse-width-modulation (temporal) throttling at something like 10-20hz, not just deep fuel flow throttling.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 12:44 pm
Quote
Leather chairs
The leather chairs?  Those are placeholders for customized foam inserts designed to cushion against vibration & impact.

Quote
Fully propulsive landing only makes sense without an atmosphere

There's confusion here because you two are using the word to mean two very different things:

Fully propulsive landing from orbit, with the entire deceleration load put onto the thrusters.

Propulsive landing from terminal velocity, with maybe 7500 out of 7600 of the meters per second dV required, dissipated in aerobraking, and the thrusters used to perform slight control burns on the angle of reentry, and to descend the final 100m/s to the pad at low altitude without using a significant parachute.

The latter sort makes sense on Earth if the alternative, a parachute, would destroy the ability to do controlled, reusable landing to a pad, and if the launch abort system needed at the beginning of the mission can do double duty.
Quote
shirtsleeves control panel
This struck me because Orion explicitly disclaims it here in favor of glove-friendly consoles with edge buttons:
https://www.youtube.com/watch?v=22I7XzXCTr4
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 05/30/2014 12:48 pm
What are these thingies at the top of the trunk. 6 around the edges

Those look like tanks. Consumables to extend flight time ... extra propellant ... or something.

Given the trunk will be drop before athmospheric reentry that might be extra propellant for the SuperDracos in case of emergency. Just guessing.

I doubt that it is propellant (even though it is possible). The propellants are pressurized at 1000psi and I think it is probably too "scary" a proposition to carry that high a pressure across the umbilical "claw". Also, all the other tanks are round and I doubt they would use 2 different designs without good reason. (Feeding the superdracos directly would also need large diameter hoses, but I think there is no need to do that--regular dracos probably have better ISP for orbital maneuvers and there is no hurry).

(If you REALLY wanted more on-orbit propellant, however, you would probably prefer to vent helium on-orbit to reduce pressure, before transferring propellant slowly across at moderate pressure; It would likely be easier to put additional dracos in the trunk to make it a full service module).

... maybe its additional oxygen tanks for a "long duration option" kit...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/30/2014 12:51 pm
What are these thingies at the top of the trunk. 6 around the edges 4 sqarish one in the center and some small ones. I think they are new for V2, except maybe some of the small ones.

The things around the circumference of the trunk are probably structural lightening cut-outs.

The four boxes are probably battery packs. The Dragon-2 is largely dependent on on-board batteries but it wouldn't really make sense to load more onto the return vehicle than is really needed worst-case for descent and recovery after an abort (say 24-48 hours of normal vehicle operations at most). The rest of the battery capacity can be carried on the trunk instead, leaving more room inside the spacecraft's service bays for propellent and ECLSS consumables.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 12:52 pm
Quote
Leather chairs
The leather chairs?  Those are placeholders for customized foam inserts designed to cushion against vibration & impact.

Quote
Fully propulsive landing only makes sense without an atmosphere

There's confusion here because you two are using the word to mean two very different things:

Fully propulsive landing from orbit, with the entire deceleration load put onto the thrusters.

Propulsive landing from terminal velocity, with maybe 7500 out of 7600 of the meters per second dV required, dissipated in aerobraking, and the thrusters used to perform slight control burns on the angle of reentry, and to descend the final 100m/s to the pad at low altitude without using a significant parachute.

I'd guess they have to preserve closer to 1,000m/s of deltaV, rather than 100m/s.  My guess would be 500m/s or so, at least.  And that's a lot of propellant weight you have to carry through the entire mission.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Optimist on 05/30/2014 12:57 pm
What are these thingies at the top of the trunk. 6 around the edges

Those look like tanks. Consumables to extend flight time ... extra propellant ... or something.

Was wondering about the possibility that they can just switch "Trunks" for different missions, after reading some guesses about the Dragon V2 elsewhere here.
If so, for a lunar mission they would want a more "able" trunk, for extended life support and more fuel and so on?

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/30/2014 01:07 pm
...
One thing that intrigues me is that while the solar panels only cover half the trunk, they are not symmetrical, they are on the same side. That probably means that side will be facing the sun while the other radiates.

I was thinking of reducing the overall thermal stress on the solar arrays themselves - without the need for a coolant loop, so long as you rolled at a suitable rate. Reducing the thermal stress probably enhances the life of the solar cells. So -why isn't the whole thing covered in panels then? Maybe because there IS a cover (doubling as a radiator) which protects the cells during launch, which folds into the other half. You could make the folded protector a sleeve (free to roll about the trunk's long axis) and still have 360 degrees of panelling though. The mechanisms, despite having to be space rated - would share common heritage with the other mission critical stuff. Instead of a whole new set, add a gear and a clutch (to select which bit you want to actuate - whether nose cone, or array deploys). But even as I type this, I feel that this long since passed the point of diminishing returns. Unless...

Without the expensive extendable solar panels, the trunk is very inexpensive, no need to make it re-usable.

Come on guys - if the trunk's pretty inexpensive, the nose-cap should be a helluva lot more so. Even if it is a uniquely contoured piece of metal, it's smaller, and isn't half covered in solar cells. So why would they spend the effort to retain the nosecap, when they're ditching the trunk? Is the CBM rendered inoperable once exposed to re-entry?

Also, I'm now reminded that the interstage adapter between the first and second stages of all the Falcons thus far (and even in the animation that depicts F9R) is discarded. The aerodynamics of this adapter and a simple trunk shouldn't be too dissimilar, although the adapter doesn't really get as high or as fast. However, SpaceX terms the first-stage return as a re-entry. So... how about collaborating with NASA (further) - to attach a S/HIAD to the adapter and the trunk respectively?

Regarding glass cockpits: can radiation damage be "repaired" once you have access to the equipment after each mission? Not so much in terms of getting rid of the defects, and charge traps and things introduced into the semi-conductor, but recalibrate your sensors, and the trigger levels for your software control logic. Doesn't even have to be after each mission... you could simply keep patching glitches. I don't think the mechanical stresses of launch are the limiting criterion given the stringent test requirements that these things are supposed to clear anyway. (Many many times what would be encountered in a single mission).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 05/30/2014 01:08 pm
Very nice spacecraft.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sohl on 05/30/2014 01:11 pm
What are these thingies at the top of the trunk. 6 around the edges 4 sqarish one in the center and some small ones. I think they are new for V2, except maybe some of the small ones.

Some may be additional batteries to supplement those in the capsule, but that does not account for all.

V1 had little avionics in the trunk.

( Picture captured from the animation by spaceref.com )

I agree the six things look like tanks.  I'd lean toward O2 for extended human flight time.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 05/30/2014 01:17 pm

Come on guys - if the trunk's pretty inexpensive, the nose-cap should be a helluva lot more so. Even if it is a uniquely contoured piece of metal, it's smaller, and isn't half covered in solar cells. So why would they spend the effort to retain the nosecap, when they're ditching the trunk? Is the CBM rendered inoperable once exposed to re-entry?


The nose cap is there to protect the very expensive docking mechanism during reentry.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 01:19 pm
Quote
Leather chairs
The leather chairs?  Those are placeholders for customized foam inserts designed to cushion against vibration & impact.

Quote
Fully propulsive landing only makes sense without an atmosphere

There's confusion here because you two are using the word to mean two very different things:

Fully propulsive landing from orbit, with the entire deceleration load put onto the thrusters.

Propulsive landing from terminal velocity, with maybe 7500 out of 7600 of the meters per second dV required, dissipated in aerobraking, and the thrusters used to perform slight control burns on the angle of reentry, and to descend the final 100m/s to the pad at low altitude without using a significant parachute.

I'd guess they have to preserve closer to 1,000m/s of deltaV, rather than 100m/s.  My guess would be 500m/s or so, at least.  And that's a lot of propellant weight you have to carry through the entire mission.
100m/s is a fairly conservative estimate of terminal velocity.  For *terminal descent* to surface in general, they need that, plus I think in the neighborhood of 9.8m/s * however long they burn for / 2.  For guidance to the correct target they will need some unknown amount of dV for cross-range control and wind correction.  Others informed me, when I gave a similar estimate of 1000m/s of dV for this cross-range correction, that there is in fact a small glide ratio associated with reentry capsules that are kept at a controlled orientation (usually via drag & geometry of center of mass), which tends to be larger the more elongated the capsule is.  Propulsive orientation correction can likely provide some degree of pointing, which can be used to 'steer the arrow' in effect, in an active  control loop.  Soyuz' orientation (which is controlled by some crazy rotational drag differential scheme (http://youtu.be/-l7MM9yoxII?t=12m19s) I don't understand) is essential to controlling reentry, and apparently an uncontrolled ballistic mode (a backup option that is occasionally entered into unexpectedly through software faults or if the separation fails after deorbit burn) will result in an extra several G's of acceleration and being 20km away from the recovery teams when it pops the parachutes.

There is also the deorbit burn itself, which is substantial - 115m/s for Soyuz.  Generally, my expectation was that the stronger the deorbit burn, the steeper the descent, the more accurate (due to reduced upper atmosphere flown through) the landing - but if there's an actively controlled primarily-gliding reentry, that's not necessarily the case.  Notably, the deorbit burn may be performed from thrusters in the trunk, rather than the SuperDracos on the capsule, before separation.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CuddlyRocket on 05/30/2014 01:21 pm
CNBC's Jane Wells did a spot on the launch she attended and reported that Elon said that if SpaceX lost the Commercial Crew contract that they would 'soldier on' regardless.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: wolfpack on 05/30/2014 01:24 pm
Like the Apollo-throwback green LEDs for the MET timer. :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Dr. Strangelove on 05/30/2014 01:26 pm
I propose they rename it to "TrampolineX".
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 01:30 pm
I propose they rename it to "TrampolineX".
Or T-reX for short... eater of Soyuz... :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/30/2014 01:32 pm

Without the expensive extendable solar panels, the trunk is very inexpensive, no need to make it re-usable.

Come on guys - if the trunk's pretty inexpensive, the nose-cap should be a helluva lot more so. Even if it is a uniquely contoured piece of metal, it's smaller, and isn't half covered in solar cells. So why would they spend the effort to retain the nosecap, when they're ditching the trunk? Is the CBM rendered inoperable once exposed to re-entry?
The expectation is that this will be docked, not berthed.  From what I gather, that relies on exposed rubber/plastics to maintain a flexible connection for the soft impact against the locking mechanism.  If that is exposed in reentry plasma, there may be problems of the burning sort.

see this look at Soyuz from 21m35s:
http://youtu.be/doN4t5NKW-k?t=21m35s
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/30/2014 01:34 pm
It's probably an issue of me being brought up with Apollo heritage designs but that control console (very Star Trek - TNG, for what it's worth) just doesn't 'feel' robust enough for me. I know that the current design assumption for all the CCTs and Orion too is that the flight computer will handle the vast majority of manoeuvres either automatically or in response to a push-button/touch-screen control input. However, it just looks like too much reliance has been placed on the touch screen system whose long-term response to space thermal and radiation environments is probably imperfectly understood.

The center panel is all manual switches.  Also, there are 4 touch screens, which seems like a lot of redundancy.

Unless you need 2 for each operator, so that if one side fails, the other side can fill in
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/30/2014 01:37 pm
They needed a LAS. They wanted an integrated, reusable LAS. So the hardware and fuel is there already. Why not landing with it?
Once you realize that the same fuel can be used in different flight phases which are completely exclusive (emergency and normal) and you're going to re-use the thrusters every capsule flight (letting you fine tune the design) it's obvious.

Except of course that no one seems to have thought of it before.  :(

But making it work (especially ensuring it fail safes to "emergency" thrust level" is where it gets really tricky.

Which is probably why people thought of it before, and rejected it?

IMO, what Elon does really well, is re-assess these rejected ideas in the light of changed circumstances - viz. newer associated technological capabilities. All his current companies seem to fit that mold).

Anyway, to be [pedantic], a re-usable LAS need not be integrated with the orbital vehicle. The advantages: you don't have to take all that mass up (of the hardware and fuel). There's a cost to bringing that additional mass down too (reflected in the extent of heat shield that ablates etc.) but here the propulsive deceleration pays for some of itself by reducing/eliminating the mass of other deceleration systems.

As for being able to increase the reliability of the LAS, because you're using the same thrusters on every increment: firstly, LAS engines - de facto, have to be proved reliable (prior to use) beyond the point where everyone stops caring. So, as heretic as it sounds, an addition means little. Secondly, the use regime is different for propulsive landing and LA. I don't think you'd be able to simply extrapolate statistics from one to another. The latter would require operation when all its fuel is weighed down, while being vibrated and forced in a particular direction, against adverse aerodynamic forces, by the rest of the stack etc. Now that I mention it, having to ignite when it's falling is probably more of a challenge, given the weightlessness, and the dynamic pressure on the nozzles. Still though, overcoming some challenges in one mode might lead to a compromise in performance in the other. If the argument is that SuperDracos can be tested and continued to be validated on cargo flights - in propulsive landing mode, without requiring separate budget for developmental firings - the same thing can be said of any other LAS too. Instead of jettisoning the mechanism, activate it on every launch, but after releasing it from the capsule. It'd be a firing in the same regime atleast.
[/pedantic]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: swervin on 05/30/2014 01:41 pm
Forbes has an article (http://www.forbes.com/sites/alexknapp/2014/05/29/spacex-unveils-its-new-dragon-spacecraft/) with a clear view of all seven seats.


Anyone else notice the piping on the right side of the photo along the side wall? Function? Perhaps if we look closer we can see the design may be more mature than we think with regards to built in support, attach point, plumbing, etc for all the systems were trying to theorize about, ECLSS, a crapper, etc. ;-)

Thoughts?

Splinter
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 01:52 pm
They needed a LAS. They wanted an integrated, reusable LAS. So the hardware and fuel is there already. Why not landing with it?
Once you realize that the same fuel can be used in different flight phases which are completely exclusive (emergency and normal) and you're going to re-use the thrusters every capsule flight (letting you fine tune the design) it's obvious.

Except of course that no one seems to have thought of it before.  :(

But making it work (especially ensuring it fail safes to "emergency" thrust level" is where it gets really tricky.

Which is probably why people thought of it before, and rejected it?

IMO, what Elon does really well, is re-assess these rejected ideas in the light of changed circumstances - viz. newer associated technological capabilities. All his current companies seem to fit that mold).

Anyway, to be [pedantic], a re-usable LAS need not be integrated with the orbital vehicle. The advantages: you don't have to take all that mass up (of the hardware and fuel). There's a cost to bringing that additional mass down too (reflected in the extent of heat shield that ablates etc.) but here the propulsive deceleration pays for some of itself by reducing/eliminating the mass of other deceleration systems.
An integrated LAS provides escape possibility up to orbit. An upper stage explosive malfunction is not covered by any other system.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 02:06 pm
Darn, the main stream media sucks at reporting. This article is just painful to read! Plus the comments are absolutely terrible (it seems more important whether Tony Stark was first than what Elon Musk presented there)! Lost a bit more faith in mankind, there.
http://www.cnn.com/2014/05/29/us/spacex-new-spacecraft/index.html?hpt=hp_t2
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 02:08 pm
An upper stage explosive malfunction is not covered by any other system.


It was covered by the SM for Apollo and retrograde section for Gemini
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: butters on 05/30/2014 02:09 pm
After all the speculation, the finned trunk was the least interesting aspect of the Dragon 2 reveal. Still expendable  :(

The operable nosecone is cool (also something that's been speculated before), the SuperDraco installations look very nice on the spacecraft (and the dual-thruster individually-armored nacelles are clearly well thought-out), and the five generously-sized windows make us all jealous of those who will get to fly in it.

But the star of the show was that flip-down control panel. What a sweet piece of hardware (no to mention software)! Elon being Elon, he nervously rushed through that part, barely acknowledging the futuristic-looking control stick. Very nice industrial design. I imagine Jonny Ive nodding his head in approval.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CraigLieb on 05/30/2014 02:10 pm
Some comments about the display and control concept (10 years experience in aircraft cockpits speaking here)
1) The displays may be subject to considerable vibration and may need to have a middle support for the large span all of which may have or need some vibration isolation or control in the mounting.

2) The idea that anyone is going to reach up and touch the displays during launch or any other significant acceleration or deceleration is unlikely. This makes them displays only during those phases, but can be controls in other phases of flight like zero gee.

3) I expect the joystick will have to be lowered to the arm-rest otherwise even in zero Gee if the pilot is controlling the vehicle, thrust will feed back into unintended arm movement and a pilot induced oscillation (PIO) could occur. That is why joysticks are typically adjacent to the arm rest.

4) The primary question about this collection is, are they pilots (having actual control of the vehicle, participating in emergency recovery, guiding the vehicle in phases some phases of flight), or are they passengers? If they are pilots, they may need back-up instrumentation in the event of a full-panel display failure. Displays do fail, and even all the displays can go dark due to single point power connections failure, failure in the graphics distribution/cabling, etc. This has happened a pilot friend of mine doing ferry flight of a 767 after maintenance. That is why most air vehicles have back-up instruments that tend to be mechanically driven or at least electro-mechanically driven.  I might expect these back up instruments to be centered between the two seats. Conveniently, the SpaceX logo occupies the ideal location for that instrument collection. The large SpaceX logo is nice for marketing, but is actually a waste.  I would hope back-up instruments could be placed at that location in future vehicles or updates to this one.

5) Having redundancy of controls is a useful concept. The displays might benefit from having a remote display control device that the pilots can move across the displays. Computer users with touch screens might understand this as having a mouse in addition to the touch screen. Pilots are familiar with the Hands on Throttle and Stick (HOTAS) concept which provides for cursor controls, display selection using a number of stick mounted buttons. The stick would be the joystick shown, but in modified form.  This may not be necessary, but is could be a useful addition to reduce other concerns. I have attached an image from a commercial game joystick for example that models a relatively modern fighter stick and throttle.

6)  The graphics shown and the text shown on these screens may be notional. Text may have to be larger to remain readable in high vibration environment of launch and return. Graphic elements that act as buttons or controls on touch screens tend to be larger than a desktop mouse environment to be effective.  I would expect these elements to be around 1.5 to 2 inches across.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lar on 05/30/2014 02:17 pm
snip a very confusing post with multiple unattributed quotes

Note to all readers...

Please do not quote people without attribution. The forum makes it easy to do this right. Use the "quote" link while viewing a post, not the generic reply, and don't use the "quote" button while composing, that's just for things you are quoting from elsewhere (wikipedia or what have you)

 When citing multiple people, use the "add quote" while viewing a post you want to cite (scroll down while composing)

Do this repeatedly, and you may find your posts removed without further warning.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 05/30/2014 02:22 pm
Darn, the main stream media sucks at reporting. This article is just painful to read! Plus the comments are absolutely terrible (it seems more important whether Tony Stark was first than what Elon Musk presented there)! Lost a bit more faith in mankind, there.
http://www.cnn.com/2014/05/29/us/spacex-new-spacecraft/index.html?hpt=hp_t2 (http://www.cnn.com/2014/05/29/us/spacex-new-spacecraft/index.html?hpt=hp_t2)

With entrepreneurs like Musk interested in space it does not matter about the masses braying on about "this money should be spent on earth instead" mentality.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ThereIWas3 on 05/30/2014 02:26 pm
What struck me is that the seats look like they borrowed them from Tesla.  They do not look
supportive enough, especially of the head and legs.  And there was no shock absorbing support
visible underneath them.  So those are probably just for show.  The real seats may indeed
have integral side-mount controls for use under acceleration.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 02:36 pm
What struck me is that the seats look like they borrowed them from Tesla.  They do not look
supportive enough, especially of the head and legs.  And there was no shock absorbing support
visible underneath them.  So those are probably just for show.  The real seats may indeed
have integral side-mount controls for use under acceleration.
They don't look much less comfortable or useful than the ones in the CST-100 and Orion mockups to me.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Hauerg on 05/30/2014 02:45 pm
An upper stage explosive malfunction is not covered by any other system.


It was covered by the SM for Apollo and retrograde section for Gemini
Apollo SM engine had a T/W ratio of something like 0.27!
Ok for leaving a dying Stage 2 or 3 behind, yes, but not outrunning anything involving explosions?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 02:50 pm
An upper stage explosive malfunction is not covered by any other system.


It was covered by the SM for Apollo and retrograde section for Gemini
Apollo SM engine had a T/W ratio of something like 0.27!
Ok for leaving a dying Stage 2 or 3 behind, yes, but not outrunning anything involving explosions?

At that point, with a reduced atmosphere, the blast effects are reduced.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lar on 05/30/2014 02:53 pm
People critiquing the design choices (why take LAS fuel up and down, why have a nose cone, etc etc) need to repeat the SpaceX mantra, then reevaluate their criticism in light of that mantra.

SpaceX optimizes for cost. NOT weight savings, not efficiency, not anything else. The goal of the company is to reduce the price of access to space. If taking some stuff up that is brought down again reduces cost, they will do that. Even if other companies rejected that choice before.

Sometimes weight savings result in cost savings. But not always.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mark S on 05/30/2014 02:54 pm
I find it interesting that they have changed the iso-grid machined elements of the pressurized structure from what they use for Dragon 1. The new pattern appears to be some kind of iso-grid/hexa-grid hybrid.

1st image - Dragon 1 pattern.
2nd image - Dragon 2 pattern.

Hm, I noticed that too. But if you look closely, you will see that the pattern is still an isogrid, made of triangles, but that each triangle also has what appear to be internal stiffeners. So maybe it should be called "augmented isogrid," or maybe "Isogrid v2 (TM)". :)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/30/2014 02:54 pm
Offshoot thread idea (that I'm not going to start) would be to ask "Is Elon just doing a mashup / remix of all the other peeps stuff?"

Everything is a remix: http://everythingisaremix.info/

I'm always amazed at how many people seem to chase the "originality" unicorn.  What matters is that Elon has created a state of the art integrated system with all the best ideas and technology out there, not whether or not he was "first" with any given piece.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/30/2014 03:32 pm
Also, I'm now reminded that the interstage adapter between the first and second stages of all the Falcons thus far (and even in the animation that depicts F9R) is discarded.

No, it comes back on top of S1.

(NB this is only on-topic, insofar as it relates to disposition of Dragon's trunk.)

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/30/2014 03:34 pm
I find it interesting that they have changed the iso-grid machined elements of the pressurized structure from what they use for Dragon 1. The new pattern appears to be some kind of iso-grid/hexa-grid hybrid.

1st image - Dragon 1 pattern.
2nd image - Dragon 2 pattern.

Hm, I noticed that too. But if you look closely, you will see that the pattern is still an isogrid, made of triangles, but that each triangle also has what appear to be internal stiffeners. So maybe it should be called "augmented isogrid," or maybe "Isogrid v2 (TM)". :)

"Fractal Isogrid" sounds much cooler, IMO.

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/30/2014 04:09 pm
t that point, with a reduced atmosphere, the blast effects are reduced.

Additionally, there is the issue of an ignition source at the exact point where the vented LOX and propellent mix. That's going to be statistically rare. I'd think the big problem would be an off-axis tumble from the venting propellent/oxidiser.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bubbagret on 05/30/2014 04:14 pm
I think they should re-brand it and sell it thru Tesla as a 5 window coupe, the Tesla Trampoline.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 04:16 pm
Day after impressions...

Negatives first:
 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.
 - And the interior, it was basically just a step up from the last interior - just flashier seats and a control panel. The final flight interior will look QUITE different. Not a single iso-grid panel will be visible.
 - Even the CG model was higher fidelity, showing parachute line risers, drogue locations, and other detail.  (see image)

Positives:
 + interesting to see windows, but I wonder why they went with oval windows - but 5 large windows is excellent
 + hatch design makes more sense
 + after seeing this, and the impressive throttling/cycling of the latest SD test video, propulsive landing looks more plausible
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sublimemarsupial on 05/30/2014 04:19 pm

 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.


According to helodriver over on the updates thread (who asked elon last night), this vehicle will be going to orbit.

http://forum.nasaspaceflight.com/index.php?topic=34841.msg1206955#msg1206955
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 04:25 pm

 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.


According to helodriver over on the updates thread (who asked elon last night), this vehicle will be going to orbit.

http://forum.nasaspaceflight.com/index.php?topic=34841.msg1206955#msg1206955

Then the "flight hardware" is just the pressure vessel. I can see this being used for the abort tests perhaps, but I would expect it to be basically rebuilt from the pressurized hull to be able to fly in space.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TrueBlueWitt on 05/30/2014 04:27 pm
I find it interesting that they have changed the iso-grid machined elements of the pressurized structure from what they use for Dragon 1. The new pattern appears to be some kind of iso-grid/hexa-grid hybrid.

1st image - Dragon 1 pattern.
2nd image - Dragon 2 pattern.

Hm, I noticed that too. But if you look closely, you will see that the pattern is still an isogrid, made of triangles, but that each triangle also has what appear to be internal stiffeners. So maybe it should be called "augmented isogrid," or maybe "Isogrid v2 (TM)". :)

"Fractal Isogrid" sounds much cooler, IMO.

cheers, Martin


Here's my $.02 FWIW

It's really a creative superposition of two grid patterns optimized for different purposes.

Traditional IsoGrid I would think is well optimized for in plane and buckling loads.

The "HexaGrid" superimposed on it is probably better optimized for pressure loads. (think Geodesic Dome or Buckyball/BuckyTube)

Might have to build a quick FEA model and see.. hmmmm..
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: HIP2BSQRE on 05/30/2014 04:30 pm
Some comments about the display and control concept (10 years experience in aircraft cockpits speaking here)
1) The displays may be subject to considerable vibration and may need to have a middle support for the large span all of which may have or need some vibration isolation or control in the mounting.

2) The idea that anyone is going to reach up and touch the displays during launch or any other significant acceleration or deceleration is unlikely. This makes them displays only during those phases, but can be controls in other phases of flight like zero gee.

3) I expect the joystick will have to be lowered to the arm-rest otherwise even in zero Gee if the pilot is controlling the vehicle, thrust will feed back into unintended arm movement and a pilot induced oscillation (PIO) could occur. That is why joysticks are typically adjacent to the arm rest.

4) The primary question about this collection is, are they pilots (having actual control of the vehicle, participating in emergency recovery, guiding the vehicle in phases some phases of flight), or are they passengers? If they are pilots, they may need back-up instrumentation in the event of a full-panel display failure. Displays do fail, and even all the displays can go dark due to single point power connections failure, failure in the graphics distribution/cabling, etc. This has happened a pilot friend of mine doing ferry flight of a 767 after maintenance. That is why most air vehicles have back-up instruments that tend to be mechanically driven or at least electro-mechanically driven.  I might expect these back up instruments to be centered between the two seats. Conveniently, the SpaceX logo occupies the ideal location for that instrument collection. The large SpaceX logo is nice for marketing, but is actually a waste.  I would hope back-up instruments could be placed at that location in future vehicles or updates to this one.

5) Having redundancy of controls is a useful concept. The displays might benefit from having a remote display control device that the pilots can move across the displays. Computer users with touch screens might understand this as having a mouse in addition to the touch screen. Pilots are familiar with the Hands on Throttle and Stick (HOTAS) concept which provides for cursor controls, display selection using a number of stick mounted buttons. The stick would be the joystick shown, but in modified form.  This may not be necessary, but is could be a useful addition to reduce other concerns. I have attached an image from a commercial game joystick for example that models a relatively modern fighter stick and throttle.

6)  The graphics shown and the text shown on these screens may be notional. Text may have to be larger to remain readable in high vibration environment of launch and return. Graphic elements that act as buttons or controls on touch screens tend to be larger than a desktop mouse environment to be effective.  I would expect these elements to be around 1.5 to 2 inches across.


You may want to contact Spacex about some of your suggestions.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DMeader on 05/30/2014 04:36 pm
I have to agree with Lars_J here. Despite what was said, the whole thing struck me as a mock-up as well, or at the very most some test articles put together for the show.

Oh, and that propulsive landing thing concerns me. Have they cleared all the black zones, like a thruster failure when they are too low-and-slow to deploy the chutes?

I don't mean to throw cold water on the proceedings. I've just seen too many neato presentations over the years.  I'll get excited when something is on the pad ready to fly, but not now.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 04:37 pm

 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.


According to helodriver over on the updates thread (who asked elon last night), this vehicle will be going to orbit.

http://forum.nasaspaceflight.com/index.php?topic=34841.msg1206955#msg1206955
I have been wondering about all this as well. It looked like a mockup to me from the exterior, at least (too few openings and ridges, too smooth all over, bottom TPS not tiled). But several sources have claimed that this is not a mockup but real flight hardware. So I don't know what to believe.
Maybe the external shell is just not final yet?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 04:38 pm
Day after impressions...

Negatives first:
 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.
 - And the interior, it was basically just a step up from the last interior - just flashier seats and a control panel. The final flight interior will look QUITE different. Not a single iso-grid panel will be visible.
 - Even the CG model was higher fidelity, showing parachute line risers, drogue locations, and other detail.  (see image)

Positives:
 + interesting to see windows, but I wonder why they went with oval windows - but 5 large windows is excellent
 + hatch design makes more sense
 + after seeing this, and the impressive throttling/cycling of the latest SD test video, propulsive landing looks more plausible
The oval windows would be less prone to stress cracks than square ones is my line of thinking...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: butters on 05/30/2014 04:38 pm
Unfinished flight hardware is better than a well-manicured mockup in my book. Adding storage lockers is not such a big deal, and I expect that the insulation is between the aeroshell and the pressure vessel, not lining the interior walls. The only controls that matter during launch or reentry are the the physical buttons on the center panel. There doesn't need to be a side-stick or whatever for manual control during high-g phases. That's silly. The dash-mounted control stick is clearly intended for the docking phase of the mission.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 04:38 pm
Oh, and that propulsive landing thing concerns me. Have they cleared all the black zones, like a thruster failure when they are too low-and-slow to deploy the chutes?
Yes, it can still land safely even with two thrusters failing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 04:41 pm
My surprise was not that they chose oval over square windows - but oval over round windows.

I am very impressed by their size, though!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: aero on 05/30/2014 04:42 pm
Discussion question. Do we know the

dry mass,
wet mass and
payload

of the returning Dragon V2?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: obi-wan on 05/30/2014 04:44 pm
Day after impressions...

Negatives first:
 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.
 - And the interior, it was basically just a step up from the last interior - just flashier seats and a control panel. The final flight interior will look QUITE different. Not a single iso-grid panel will be visible.
 - Even the CG model was higher fidelity, showing parachute line risers, drogue locations, and other detail.  (see image)

(Snipped)


While I think the design is great, for me it fell short of hopes/expectations, which was for a vehicle very close to flight readiness. To me, it's currently a vehicle designed by a rocket guy and a car guy. (Well, duh...) The four "systems" Elon showed were all propulsion components, and I suspect three of them have been flying in Dragon cargo vehicles from the beginning. The inside is what a car person would use to sell a car - rich seats, cool displays - but other than that, the spacecraft was empty. What I wanted to see was to wheel out CO2 scrubbers, and air heat exchangers, and ventilating fans, and (as so many people have said) suits. (Yes, I'm a life support weenie...) My bottom line: great spacecraft, but only the smallest of baby steps towards a _manned_ spacecraft.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: butters on 05/30/2014 04:46 pm
Oh, and that propulsive landing thing concerns me. Have they cleared all the black zones, like a thruster failure when they are too low-and-slow to deploy the chutes?
Yes, it can still land safely even with two thrusters failing.

Also, Elon clarified the descent sequence: the SuperDracos will be test-fired at a high enough altitude so that the chutes can be deployed if there are any anomalies. Otherwise the vehicle proceeds with propulsive landing, and it can safely land with two thrusters out. The thruster pairs are housed in armored nacelles to minimize the risk of one thruster failure taking out the other. If there are any "black zones" (btw -- not a good phrase to use if you want to avoid coming off as a concern-troll), they aren't immediately obvious to me. Seems well thought-out.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 04:48 pm
My surprise was not that the chose oval over square windows - but oval over round windows.

I am very impressed by their size, though!
Oval would give a larger field of view fore and aft while seated I guess and would allow more of them to be placed from a structural standpoint...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 04:53 pm
If you look at the highest resolution pictures, you can see quite a few little imperfections on the surface, which makes it look a lot less like a mockup. Rivet marks, ridges, lines in the heat shield. Helodriver's photos are very high resolution and make it easy to see these imperfections.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 04:56 pm
An upper stage explosive malfunction is not covered by any other system.


It was covered by the SM for Apollo and retrograde section for Gemini
Apollo SM engine had a T/W ratio of something like 0.27!
Ok for leaving a dying Stage 2 or 3 behind, yes, but not outrunning anything involving explosions?

At that point, with a reduced atmosphere, the blast effects are reduced.

Debris generated would have been the same, and they even fly faster.  The very large exposed engine bell would be the first to get damaged. 

As Hauerg said, it was ok to leave a dead stage with.

The Dragon escape system OTOH is very well protected, since it is also designed to survive re-entry.   Therefore, a completely different, and much more capable, beast.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 05/30/2014 05:01 pm
I'm not disappointed at the state of this capsule.  Sure the interior is quite incomplete, but considering that the money invested already in this design is at 1/2 the expected cost to have a fully working, manned article - this is to be expected.   I'll give them a pass on some of those aspects considering that they have flown several older design capsules.

SpaceX could have stayed with the existing capsule design but they have made substantial revisions (though I'm curious if the pressure vessel is about the same or not, it looks fairly similar).   
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 05:07 pm
If you look at the highest resolution pictures, you can see quite a few little imperfections on the surface, which makes it look a lot less like a mockup. Rivet marks, ridges, lines in the heat shield. Helodriver's photos are very high resolution and make it easy to see these imperfections.

Really? Look closer. (Image #1) The inside structure may be flight hardware, but the coated exterior doesn't appear to be, unless they drastically changed/upgraded materials. The Draco thrusters appear to be mockups as well.

Compare with an actual flight article, the CRS-3 Dragon being mated. (Images #2 and #3)

I'm not trying to be nitpicky, but I wish they had focused less on the "flight hardware" aspect.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Hauerg on 05/30/2014 05:07 pm

 - My biggest disappointment (even as a card-carrying SpaceX fan) ;) was how was how this was just a slightly higher fidelity mockup than the previous one. Flight hardware? No, not really.


According to helodriver over on the updates thread (who asked elon last night), this vehicle will be going to orbit.

http://forum.nasaspaceflight.com/index.php?topic=34841.msg1206955#msg1206955
I have been wondering about all this as well. It looked like a mockup to me from the exterior, at least (too few openings and ridges, too smooth all over, bottom TPS not tiled). But several sources have claimed that this is not a mockup but real flight hardware. So I don't know what to believe.
Maybe the external shell is just not final yet?

Looking at high resolution pics shows that the bottem TPS is indeed tiled.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 05:07 pm

Debris generated would have been the same, and they even fly faster.  The very large exposed engine bell would be the first to get damaged. 


Debris was never the main issue, it was the blast wave effects.

The Dragon escape system OTOH is very well protected, since it is also designed to survive re-entry.   Therefore, a completely different, and much more capable, beast.


Not a real selling point.  Provides very marginal if any increase in safety over other systems.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 05/30/2014 05:10 pm
You don't put tested engines in a mock up.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Galactic Penguin SST on 05/30/2014 05:13 pm
Discussion question. Do we know the

dry mass,
wet mass and
payload

of the returning Dragon V2?

Do we even know the corresponding figures for Dragon v1?  ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 05:13 pm
You don't put tested engines in a mock up.


You do, if you aren't going to use the engines anymore.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Joel on 05/30/2014 05:16 pm
So, the Dragon is able to two SDs out? Could that be a two SDs on the same side? If so, does it mean that it can land tilted? If so, why can't it land with three SDs out?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 05:18 pm
Looking at high resolution pics shows that the bottem TPS is indeed tiled.
Indeed, it looks like they put a heavy thick coat of paint over everything that seems to cover all the fine ridges and seams. I still don't see the chute guides though.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/30/2014 05:22 pm
You don't put tested engines in a mock up.
You do, if you aren't going to use the engines anymore.

How hard is it to safe hypergolic engines after firing?  Not just to the "won't kill an astronaut" level, but to the point where you would feel comfortable having random members of the public peer into the bell?

I think the discussions here about what constitutes "flight worthy" are a bit strange.  Obviously this article is not going to go directly out to the flight test range tomorrow, just look at the published flight test schedules.  But I think we can take Elon's word that a large amount of the mass displayed will eventually be in orbit.  Sure, there might be extra holes and fittings in the outer shell, and there may (or may not) be lockers and storage and other extra stuff inside.  But this isn't a cardboard cutout just for hanging in the spacex lobby.  This is the incomplete and in-progress *actual flight test article*.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 05:28 pm

Debris generated would have been the same, and they even fly faster.  The very large exposed engine bell would be the first to get damaged. 


Debris was never the main issue, it was the blast wave effects.

The Dragon escape system OTOH is very well protected, since it is also designed to survive re-entry.   Therefore, a completely different, and much more capable, beast.


Not a real selling point.  Provides very marginal if any increase in safety over other systems.

Both your points are unsubstantiated.

The first one is completely wrong:  You just said blast waves are weaker in the upper atmosphere.  (True of pressure waves, btw, but not of the actual gas front)   But there's no doubt that an engine bell is susceptible to debris impact, that it sits front and center between the capsule and the exploding stage, and that a dented engine bell is a bad thing,

The second one is just a vague statement.  And wrong.  The system is, in fact, designed to survive reentry, and the exploding second stage is exactly in the right direction for that protection to be effective.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Prober on 05/30/2014 05:30 pm
Darn, the main stream media sucks at reporting. This article is just painful to read! Plus the comments are absolutely terrible (it seems more important whether Tony Stark was first than what Elon Musk presented there)! Lost a bit more faith in mankind, there.
http://www.cnn.com/2014/05/29/us/spacex-new-spacecraft/index.html?hpt=hp_t2

wait till you watch this video report that was on this morning.

http://www.cbsnews.com/videos/spacex-unveils-space-shuttle-replacement-the-dragon-v2/

 Michio Kaku is excellent however Charlie Rose hasn't got a clue.  Sounds like he doesn't know we have an ISS up there for 15 years.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 05/30/2014 05:35 pm
The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.


Quote
shirtsleeves control panel
This struck me because Orion explicitly disclaims it here in favor of glove-friendly consoles with edge buttons: <snip>

Orion's presentation struck me as showing a craft that has been stuck way too long in rigid development so technology has advanced and they haven't redirected.

They made two arguments for the disclaim, glove use and loose things triggering the panel in zero-g.

- Others have commented on how glove-compatible touch screens are now de facto used in some smartphones and cars.

- Quick test shows my smartphone is eminently capable of distinguishing between hardware bumps and intended pushes or slides. Likely by the acceleration profile alone, which is also how some softwares distinguish individuals. (Admittedly from longer interaction, often writing tasks, but affirming the principle.)

As I understand it SpaceX has freedom to choose the technology, and reusing Tesla technology (like for the batteries) would be their rapid development, cheap production pathway. I therefore assume we saw all the controls there ever will be.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: baldusi on 05/30/2014 05:38 pm
Did I counted right? From the front there are 3 Dracos on the side of the SD pods. On the side, there's 1 Draco on each side of each pod. And from the back, looking at the CGI docking sequence, I counted another 3 per pod, mirroring the front. Thus, 16 Dracos on each Dragon. Interesting that they had 18 on v1. But then they won't need them for deorbit burn, among other things.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/30/2014 05:44 pm
We already knew pretty much everything shown, and propulsive landing only makes sense on planetary bodies lacking a dense atmosphere.


Seriously? Propulsive landing doesn't make sense on Earth? Because repacking parachutes is a cheap and completely reliable process?  Because throwing away your LAS makes more sense than reusing it? Lee Jay, perhaps nothing will satisfy you.

Parachutes and lifting surfaces weigh much less than propellant for a propulsive landing, and until mass-to-orbit is dirt-cheap, that matters.  Mass to orbin isn't dirt-cheap.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 05:46 pm
Parachutes and lifting surfaces weigh much less than propellant for a propulsive landing..
This has been debated to death, and is far from certain.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DMeader on 05/30/2014 05:47 pm
(btw -- not a good phrase to use if you want to avoid coming off as a concern-troll)

I come across as a realist, not a amazing people, and I say it as it is. Besides, Wayne Hale uses that term. if it's good enough for him, it's good enough for me.

(and I don't appreciate being called a troll for asking a reasonable question)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 05/30/2014 05:54 pm

They got rid  of:
- Extendable mechanism
- solar panel fairings
- large area of costly solar panels
- a very critical failure point (deploying)
- associated weight
- associated drag
- clearance issues (hypothetical narrow space for docking)

But now they have the following limitations:
- less operation time (7-10 days)
- more battery weight (probably less than the solar panels weight + drag effect)
- craft orientation is not independent of power output
Where do these first two limitations spring from?

Where does the last one limitation spring from?

The maximum power output of the battery+panel package would depend on craft orientation, but if you need to use that presumably you are in trouble already.

Rather, the long term power input to the package depend on orientation. But (as I believe has been mentioned) that typically applies to ISS docking, where the craft instead is supplied externally.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 05:54 pm

Both your points are unsubstantiated.

The first one is completely wrong:  You just said blast waves are weaker in the upper atmosphere.  (True of pressure waves, btw, but not of the actual gas front)   But there's no doubt that an engine bell is susceptible to debris impact, that it sits front and center between the capsule and the exploding stage, and that a dented engine bell is a bad thing,

The second one is just a vague statement.  And wrong.  The system is, in fact, designed to survive reentry, and the exploding second stage is exactly in the right direction for that protection to be effective.


Wrong again.  Have you worked a manned spacecraft and abort systems before?   Know something before posting.  You are wrong on both accounts and have nothing repeat nothing to support your claims.   Abort systems were jettisoned after first stage separation and upperstage start because:

a.  The blast and debris effects would be reduced and the existing thrusters would be sufficient to separate the spacecraft from the problem.
b.  The potential for problems would be low at this point

The second statement is 100% deadon. Dragons integral abort system provides a very marginal increase in safety over previous abort concepts for upperstages problems.  So marginal that previous abort systems were jettisoned on the way to orbit vs waiting until orbit was achieved.





Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/30/2014 05:57 pm
SpaceX optimizes for cost. NOT weight savings, not efficiency, not anything else. The goal of the company is to reduce the price of access to space. If taking some stuff up that is brought down again reduces cost, they will do that. Even if other companies rejected that choice before.

Well put - you don't increase the operational range of an airliner by jettisoning the wheels at takeoff to reduce weight, but that's exactly how rocket science has worked up until now. It's interesting to watch the ULA and Arianne executives try to figure that out in media interviews.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 05:59 pm
The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.

Seriously? I take it you've never actually read any of the informational surveys ON Space Tourism then? Heck the biggest "concern" the airline industry has over new aircraft designs (such as the BWB) is that they lack window access which has proven to be a major "issue" with most passengers!

Quote
I therefore assume we saw all the controls there ever will be.

I don't think so. Really, it NEEDS the key-fob door opening thing! It's just screaming for one :)

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: grythumn on 05/30/2014 06:01 pm
The telemetry from the CRS-3 booster splashdown was collected by an antenna made from a pizza dish stuck in his plane's window.

That explains a lot of the bit flipping... Error 106: insufficient parmesan.

-Bob
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 06:02 pm

Both your points are unsubstantiated.

The first one is completely wrong:  You just said blast waves are weaker in the upper atmosphere.  (True of pressure waves, btw, but not of the actual gas front)   But there's no doubt that an engine bell is susceptible to debris impact, that it sits front and center between the capsule and the exploding stage, and that a dented engine bell is a bad thing,

The second one is just a vague statement.  And wrong.  The system is, in fact, designed to survive reentry, and the exploding second stage is exactly in the right direction for that protection to be effective.


Wrong again.  Have you worked a manned spacecraft and abort systems before?   Know something before posting.  You are wrong on both accounts and have nothing repeat nothing to support your claims.   Abort systems were jettisoned after first stage separation and upperstage start because:

a.  The blast and debris effects would be reduced and the existing thrusters would be sufficient to separate the spacecraft from the problem.
b.  The potential for problems would be low at this point


The basic principles don't care whether you've "worked on one".

I know enough to differentiate between the pressure wave, the expanding gas front, and the debris, and know how they're affected by altitude.

I know enough to know that engine bells can be dented pretty easily by flying debris.

I know that a dented engine bell will produce off-axis thrust, at best.

I know that if t/w is 0.25, you're only moving away from the exploding stage at, well, 0.25g.  If the engine bell is still ok.  Not enough.

As for chance for problems on second stage - yeah - but the question was whether Dragon/Falcon have an escape option all the way through flight, not whether one is necessary.   

Quote
The second statement is 100% deadon. Dragons integral abort system provides a very marginal increase in safety over previous abort concepts for upperstages problems.  So marginal that previous abort systems were jettisoned on the way to orbit vs waiting until orbit was achieved.

If ever there was an example of circular logic...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 06:04 pm
Parachutes and lifting surfaces weigh much less than propellant for a propulsive landing, and until mass-to-orbit is dirt-cheap, that matters.  Mass to orbin isn't dirt-cheap.
But the crewed Dragon does not have to do more mass to orbit than it does. That's the weight of 7 people plus 1000 pounds of cargo. More probably wont fit into the capsule anyway. So why bother with having more capability, when that only costs processing time and manpower for reusing the capsule?
Also want to point out that they need the engines and propellant for launch abort anyway. So it is not like there was any way around it. I think they might also do some of the orbital maneuvering with them.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: butters on 05/30/2014 06:05 pm
If you look at the highest resolution pictures, you can see quite a few little imperfections on the surface, which makes it look a lot less like a mockup. Rivet marks, ridges, lines in the heat shield. Helodriver's photos are very high resolution and make it easy to see these imperfections.

Really? Look closer. (Image #1) The inside structure may be flight hardware, but the coated exterior doesn't appear to be, unless they drastically changed/upgraded materials. The Draco thrusters appear to be mockups as well.

Compare with an actual flight article, the CRS-3 Dragon being mated. (Images #2 and #3)

I'm not trying to be nitpicky, but I wish they had focused less on the "flight hardware" aspect.

They did upgrade the TPS material. Elon said that this is PICA-X version 3. The flown Dragons used version 1, and he mentioned that future Dragon V1 spacecraft will use a PICA-X version 2 which was not shown. I don't know how drastically different the new versions are, but perhaps we can speculate that it's more carbon and less phenolic resin?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 06:10 pm
The telemetry from the CRS-3 booster splashdown was collected by an antenna made from a pizza dish stuck in his plane's window.

That right there is probably the most amazing and insightful bit of information ever.   

The pizza dish needs to be hung up for display at Hawthorne.

And they should seriously equip that airplane, like with a Pringles can or something, since odds are this scenario will recur.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/30/2014 06:17 pm
If you look at the highest resolution pictures, you can see quite a few little imperfections on the surface, which makes it look a lot less like a mockup. Rivet marks, ridges, lines in the heat shield. Helodriver's photos are very high resolution and make it easy to see these imperfections.

These were clearly visible on the Livestream live feed last.

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 06:21 pm
If you look at the highest resolution pictures, you can see quite a few little imperfections on the surface, which makes it look a lot less like a mockup. Rivet marks, ridges, lines in the heat shield. Helodriver's photos are very high resolution and make it easy to see these imperfections.

Really? Look closer. (Image #1) The inside structure may be flight hardware, but the coated exterior doesn't appear to be, unless they drastically changed/upgraded materials. The Draco thrusters appear to be mockups as well.

Compare with an actual flight article, the CRS-3 Dragon being mated. (Images #2 and #3)

I'm not trying to be nitpicky, but I wish they had focused less on the "flight hardware" aspect.

They did upgrade the TPS material. Elon said that this is PICA-X version 3. The flown Dragons used version 1, and he mentioned that future Dragon V1 spacecraft will use a PICA-X version 2 which was not shown. I don't know how drastically different the new versions are, but perhaps we can speculate that it's more carbon and less phenolic resin?

This is true - and I have seen better pictures now that show some panel lines (even the parachute guide line panels are visible) - but the flashy paint job that covers all of it would have to be removed/torn/ruined to allow access to do any work on the vehicle.

I have attached some contrast enhanced pictures that show more of the panel details. So my initial assessment may have to be revised a bit.

So I'm still skeptical that this is a flight article - the all-covering paint job just makes it "look" more like an item that will be trucked around to be shown at various events. But I could certainly be VERY wrong about this.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 05/30/2014 06:28 pm
The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.

Seriously? I take it you've never actually read any of the informational surveys ON Space Tourism then? Heck the biggest "concern" the airline industry has over new aircraft designs (such as the BWB) is that they lack window access which has proven to be a major "issue" with most passengers!

Seriously. But no, I wasn't aware of the airliner problem (I trust you on that one, being newbie and all), so thanks for clearing up that enigma!

New enigma: Why so _few_ windows!? Apparently, in space tourism no one can hear you scream.

Quote
I therefore assume we saw all the controls there ever will be.

I don't think so. Really, it NEEDS the key-fob door opening thing! It's just screaming for one :)

Randy

Agreed! It needs a locator and craft alarm activation too! Unfortunately ... well, see above.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 06:31 pm
An upper stage explosive malfunction is not covered by any other system.


It was covered by the SM for Apollo and retrograde section for Gemini
Apollo SM engine had a T/W ratio of something like 0.27!
Ok for leaving a dying Stage 2 or 3 behind, yes, but not outrunning anything involving explosions?

At that point, with a reduced atmosphere, the blast effects are reduced.
It is required for example in the case of a malfunction that keeps the upper stage engine running (or on an uncontrolled burn) and pushing the crew vehicle or even making it spin hard. AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RoboGoofers on 05/30/2014 06:35 pm
The edges of the superdraco cowling look like they form part of a expansion bell, like a stepped nozzle. That would be a clever design, if it is so.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 05/30/2014 06:38 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: baldusi on 05/30/2014 06:39 pm
Ok. I'm trying to count the number of Dracos (not SuperDraco) in the Dragon v2. Elon didn't mention the number in v2. In fact, he said 18 in v1 and sort of doubted about stating the number on v2.
I've not seen pictures from the back of the capsule, but looking into the side, front and the back of the CGI (which is very accurate regarding what we do see), I count either 16 or 18.
In each side of the Super Draco pods, appear to be 3 Dracos on front and back (1, 2 and 3 on the picture I numbered). Then there are clearly one on the side of each pod from the sides (5 and 6). I simply don't know if the hole on top of the side windows is a Draco or not (number ?7?). It could, but it would be the first time a Draco is arranged perpendicular to the surface. Any idea?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 06:41 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Thanks! That is a good example on how a LAS is important all the way to orbit.


Quote
The launch proceeded according to plan until T+288.6 seconds at an altitude of 145 kilometres (90 mi),[4] when the second and third stages of the booster began separation. Only three of the six locks holding the stages together released and the third stage's engine ignited with the second stage still attached below it. The third stage's thrust broke the remaining locks, throwing the second stage free but putting the booster under unanticipated strain that caused it to deviate from the proper trajectory. At T+295 seconds, the deviation was detected by the Soyuz's guidance system, which activated an automatic abort program. As the escape tower was long gone by this point, the abort had to be performed with the Soyuz's own engines. This separated the spacecraft from the third stage booster and then separated the orbital and service modules of the Soyuz from the re-entry capsule.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 05/30/2014 06:42 pm
The telemetry from the CRS-3 booster splashdown was collected by an antenna made from a pizza dish stuck in his plane's window.

The cheese is strong with this one.

But why didn't Tony Stark think of that?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 05/30/2014 06:54 pm
The telemetry from the CRS-3 booster splashdown was collected by an antenna made from a pizza dish stuck in his plane's window.

The cheese is strong with this one.

But why didn't Tony Stark think of that?

'Cause Tony Stark didn't have a whole forum full of video experts that could repair the result!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AntiAnti on 05/30/2014 06:55 pm
I wonder now about pad abort test scheduled for autumn. Does it make a sense to test abort system of Dragon V1? Or they are going to hold it off until V2 become ready for launch?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:03 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Thanks! That is a good example on how a LAS is important all the way to orbit.


Wrong, that shows the opposite that an LAS is not needed all the way to orbit, because the spacecraft thrusters can provide the same role later in the mission. (this only applies to non integral abort systems.)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:07 pm

It is required for example in the case of a malfunction that keeps the upper stage engine running (or on an uncontrolled burn) and pushing the crew vehicle or even making it spin hard. AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

wrong, see above.  Spin is not a reason, the spacecraft can detach and correct itself.  Engine not shutting down is not credible.  There are more that one way to shutdown the engines.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 05/30/2014 07:10 pm
...
We already knew pretty much everything shown, and propulsive landing only makes sense on planetary bodies lacking a dense atmosphere.
No, we suspected, assumed, and inferred much of what was shown. The exciting bit for those of us excited by this was it was now we actually know.

SpaceX thinks propulsive landing makes sense for a whole host of reasons they've listed and that have been discussed ad-nauseum.  The price of propulsive landing is burning a bit more RP-1 and LOX, which SpaceX believes is much cheaper than a disposable LAS, extra integration required, recovery operations, etc (again, discussed ad-nauseum.)

Clearly you prefer parachutes or wings.  I really don't get your argument, fuel is cheap and getting to ISS, Bigelow and other potential LEO destinations will be easily in the reach of the Dragon V2 and propulsive landing should simplify operation and reusability.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:11 pm

I made the same assumption, based on the poisoness MMH/NTO gasses, but much to my surprise the FAA/EIS seems to have no concern with it. Says the products are all H2O and N2. I tried to do some research, and could not get anything definitive, but it looked like incomplete combustion could still leave some trace gasses like nitric acid. Also SpaceX has been conducting tests at McGreggor of the SuperDracos in open air, again with no objections from anybody. Conclusion is that it is completely safe. I also found a picture from years ago by Airiane Space of MMH/NTO tests in open air.


Here are also two "open air" firings of hypergolic engines
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 07:14 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Thanks! That is a good example on how a LAS is important all the way to orbit.


Wrong, that shows the opposite that an LAS is not needed all the way to orbit, because the spacecraft thrusters can provide the same role later in the mission. (this only applies to non integral abort systems.)

I'm sorry, but that's a perfect example of the thinking paradigm of "whoo, we got out of this one alive, I guess everything was sufficient".

That incident shows that problems can occur in stage II and III. That separation event could easily have caused an explosion.  It didn't.  So what do you want to do?  Keep flying an LAS-less vehicle until you actually do have a LOC?

It's staring you right in the face.  Apollo did not have an LAS after the tower was jettisoned, and had only a very limited abort capability, pretty much sufficient to get away from a peaceful, inert, second stage.

They took the risk, and lived to tell the tale.  It doesn't mean that a modern launch system should do the same.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:14 pm
The price of propulsive landing is burning a bit more RP-1 and LOX, which SpaceX believes is much cheaper than a disposable LAS, extra integration required, recovery operations, etc (again, discussed ad-nauseum.)

Same can be said for wings.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:20 pm

I'm sorry, but that's a perfect example of the thinking paradigm of "whoo, we got out of this one alive, I guess everything was sufficient".

That incident shows that problems can occur in stage II and III. That separation event could easily have caused an explosion.  It didn't.  So what do you want to do?  Keep flying an LAS-less vehicle until you actually do have a LOC?

It's staring you right in the face.  Apollo did not have an LAS after the tower was jettisoned, and had only a very limited abort capability, pretty much sufficient to get away from a peaceful, inert, second stage.

They took the risk, and lived to tell the tale.  It doesn't mean that a modern launch system should do the same.

wrong again.  The system did what was designed to do and there was no additional risks.   Apollo was not a "limited" abort capability after LES jettison.  It was very robust.  The Apollo abort scenarios provided the same probability of survival for the post LES portion of flight as the LES did during its portion of flight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: yg1968 on 05/30/2014 07:22 pm
The price of propulsive landing is burning a bit more RP-1 and LOX, which SpaceX believes is much cheaper than a disposable LAS, extra integration required, recovery operations, etc (again, discussed ad-nauseum.)

Same can be said for wings.

Or airbags for the CST-100.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Dudely on 05/30/2014 07:24 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Thanks! That is a good example on how a LAS is important all the way to orbit.


Wrong, that shows the opposite that an LAS is not needed all the way to orbit, because the spacecraft thrusters can provide the same role later in the mission. (this only applies to non integral abort systems.)

I'm sorry, but that's a perfect example of the thinking paradigm of "whoo, we got out of this one alive, I guess everything was sufficient".

That incident shows that problems can occur in stage II and III. That separation event could easily have caused an explosion.  It didn't.  So what do you want to do?  Keep flying an LAS-less vehicle until you actually do have a LOC?

It's staring you right in the face.  Apollo did not have an LAS after the tower was jettisoned, and had only a very limited abort capability, pretty much sufficient to get away from a peaceful, inert, second stage.

They took the risk, and lived to tell the tale.  It doesn't mean that a modern launch system should do the same.

True, but in all of human spaceflight this was the only time a LAS would have been useful in orbit and it actually was not needed.

While I agree with you and think SpaceX has the right approach to integrate everything, claiming that it improves safety is just a theoretical exercise in coulda-woulda-shoulda. I think Jim's point was that this sounds like a much bigger deal than it is, which is true.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:25 pm

That incident shows that problems can occur in stage II and III. That separation event could easily have caused an explosion.  It didn't.  So what do you want to do?  Keep flying an LAS-less vehicle until you actually do have a LOC?

The same actions taken would have provided enough separation and protection to the crew in that case.  An LAS would not have provided anymore protection and actually could have put the crew at more risk.   LAS is like an ejection for an aircraft.  There is always some injury with ejection.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/30/2014 07:32 pm
a.  The blast and debris effects would be reduced and the existing thrusters would be sufficient to separate the spacecraft from the problem.
b.  The potential for problems would be low at this point
I did not know this. I had thought it was, being all solid, they were so damm heavy. You live and learn.  :)
Quote
The second statement is 100% deadon. Dragons integral abort system provides a very marginal increase in safety over previous abort concepts for upperstages problems.  So marginal that previous abort systems were jettisoned on the way to orbit vs waiting until orbit was achieved.
Could be that improving "efficiency" (I'm not sure what that means in this context) is not the design driver in this?

I'll also note that the SD thrusters are quite close to the base of the capsule they are still behind the heat shield, so (in principle) are shielded from the (notional) debris field of an exploding upper stage, unless of course the debris follows an exploding outward, then curves back in past the heat shield to clobber the SD nacelle.   :(

About the only place I've ever seen that happen is in the film "Wanted." 

IRL? I think not.  :(
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 07:38 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Thanks! That is a good example on how a LAS is important all the way to orbit.


Wrong, that shows the opposite that an LAS is not needed all the way to orbit, because the spacecraft thrusters can provide the same role later in the mission. (this only applies to non integral abort systems.)
Depends on the thrust of the spacecraft, the maximum acceleration that they can provide, vs the force applied by the upper stage.

They got lucky and still experienced very high g's.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 05/30/2014 07:42 pm
True, but in all of human spaceflight this was the only time a LAS would have been useful in orbit and it actually was not needed.
How many times was LAS used in a first stage failure? One.
How many times was LAS used in an upper stage failure? One.

Are you implying there is no need for a LAS/LES at all?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 07:45 pm

I'm sorry, but that's a perfect example of the thinking paradigm of "whoo, we got out of this one alive, I guess everything was sufficient".

That incident shows that problems can occur in stage II and III. That separation event could easily have caused an explosion.  It didn't.  So what do you want to do?  Keep flying an LAS-less vehicle until you actually do have a LOC?

It's staring you right in the face.  Apollo did not have an LAS after the tower was jettisoned, and had only a very limited abort capability, pretty much sufficient to get away from a peaceful, inert, second stage.

They took the risk, and lived to tell the tale.  It doesn't mean that a modern launch system should do the same.

wrong again.  The system did what was designed to do and there was no additional risks.   Apollo was not a "limited" abort capability after LES jettison.  It was very robust.  The Apollo abort scenarios provided the same probability of survival for the post LES portion of flight as the LES did during its portion of flight.

The original question was "how would a fragile 0.25 T/W stage be sufficient to get away from an exploding stage".

By sheer dumb luck, the third stage on that flight didn't break or spin, and so they got away ok.

Had the problem become more severe, which it had every chance to do, they would have died, where an LAS system would have saved them.

Again, you look at a set of circumstances that worked out ok at the end, and infer that therefore an LAS was not needed.

According to your method, not until you have an actual loss of crew, do you turn around and realize you needed an LAS.

Dragon is providing a unique all-the-way to orbit LAS.  If I fly on a rocket, I'd like to know that it's there, just in case the second stage does explode, or spin, or whatever.  Even if that Soyuz flight got lucky.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: baldusi on 05/30/2014 07:47 pm
The actual issue was that I had read that Dracos can't be used in atmospheric conditions. This was why SpaceX had to use a vacuum chamber for acceptance testing of the Dracos. I didn't quite understood why, and since Elon stated that v2 Dracos were improved and used for pinpoint accuracy, either the old information was wrong or this new ones can be used in atmosphere.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Halidon on 05/30/2014 07:49 pm
Guys, you might want to take it to another thread. Or perhaps just let the points already made stand and go back to discussing other aspects of the reveal.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Malderi on 05/30/2014 07:49 pm
One of the things that struck out at me is how the Dragon V2 will have to trade power for mass/on-orbit life very tightly during the development process. My understanding is that the solar arrays on the SM do not keep the capsule power-positive, and the batteries will be draining slowly while undocked.

Given that increasing solar array area would be extremely difficult, that means that hopefully SpaceX has large power margins and/or high confidence in the power requirements of the various subsystems. If they do not, then increasing load will be a matter of increasing weight significantly in the SM with larger batteries or reducing free-flight time. The systems engineers will have their hands full on that one.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 05/30/2014 07:53 pm
The price of propulsive landing is burning a bit more RP-1 and LOX, which SpaceX believes is much cheaper than a disposable LAS, extra integration required, recovery operations, etc (again, discussed ad-nauseum.)

Same can be said for wings.

Wasn't going to comment originally but what the hey :)

Actually Jim this is incorrect :) First of all because EM as head of the company has already publicly stated that HE doesn't believe this to be true so AS head of the company this is not something that SpaceX could truthfully "say" at this point :)

Secondly because "propulsive-flight-control" (focusing on the whole flight envelope rather than any one "phase" here) is by its nature a safer, more reliable system from end-to-end. Why? Parachutes and wing (lifting) flight both have unavoidable "dead-zones" where they will not function properly. Specifically they have an altitude and minimum-speed requirement respectivly below which they can't function. Propulsive is a "zero-to-maximum" system at any point. If it works at all, as long as it has propellant there are no "dead-zone" restrictions

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 07:57 pm

By sheer dumb luck, the third stage on that flight didn't break or spin, and so they got away ok.

Had the problem become more severe, which it had every chance to do, they would have died, where an LAS system would have saved them.

Again, you look at a set of circumstances that worked out ok at the end, and infer that therefore an LAS was not needed.

Wrong again,  the system is designed to separate the spacecraft from the third stage using engines at the same time an LAS would separate and fire.  however, the extra acceleration of the LAS is not needed at that point in flight.

The last sentence could not be more wrong.  The LAS is jettisoned because there are other methods of abort and it is not needed. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 05/30/2014 07:58 pm
Given that increasing solar array area would be extremely difficult, that means that hopefully SpaceX has large power margins and/or high confidence in the power requirements of the various subsystems. If they do not, then increasing load will be a matter of increasing weight significantly in the SM with larger batteries or reducing free-flight time. The systems engineers will have their hands full on that one.
I think the number given was 7 days. That seems plenty.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/30/2014 08:00 pm

Secondly because "propulsive-flight-control" (focusing on the whole flight envelope rather than any one "phase" here) is by its nature a safer, more reliable system from end-to-end. Why? Parachutes and wing (lifting) flight both have unavoidable "dead-zones" where they will not function properly. Specifically they have an altitude and minimum-speed requirement respectivly below which they can't function. Propulsive is a "zero-to-maximum" system at any point. If it works at all, as long as it has propellant there are no "dead-zone" restrictions

Randy

Not true, what dead zones will  Dream Chaser will have?  Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Kabloona on 05/30/2014 08:03 pm
The actual issue was that I had read that Dracos can't be used in atmospheric conditions. This was why SpaceX had to use a vacuum chamber for acceptance testing of the Dracos. I didn't quite understood why, and since Elon stated that v2 Dracos were improved and used for pinpoint accuracy, either the old information was wrong or this new ones can be used in atmosphere.

It may have to do with expansion ratio. Dracos have very high expansion ratios for operation in vacuum, and testing a highly expanded vacuum nozzle at atmospheric pressure can be problematic. Also, the Draco bell is truncated on a steep angle that might also cause problems in an atmospheric test.

By contrast, SuperDraco will have a much lower expansion ratio for operation near sea level, so vacuum tests are not necessary.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 08:07 pm
Ok. I'm trying to count the number of Dracos (not SuperDraco) in the Dragon v2. Elon didn't mention the number in v2. In fact, he said 18 in v1 and sort of doubted about stating the number on v2.
I've not seen pictures from the back of the capsule, but looking into the side, front and the back of the CGI (which is very accurate regarding what we do see), I count either 16 or 18.
In each side of the Super Draco pods, appear to be 3 Dracos on front and back (1, 2 and 3 on the picture I numbered). Then there are clearly one on the side of each pod from the sides (5 and 6). I simply don't know if the hole on top of the side windows is a Draco or not (number ?7?). It could, but it would be the first time a Draco is arranged perpendicular to the surface. Any idea?

There appears to be only 16 Draco thrusters. Each SD 'vane/fin' has 3 Draco on one side, and a 4th on the other side.

Dragon v1 has 18, but the extra redundancy is probably not needed, when SD's could be used in lowest throttle (pulsed very briefly) if necessary.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 05/30/2014 08:09 pm
The price of propulsive landing is burning a bit more RP-1 and LOX, which SpaceX believes is much cheaper than a disposable LAS, extra integration required, recovery operations, etc (again, discussed ad-nauseum.)

Same can be said for wings.

As has been said here before:  stick around another decade and we'll evaluate the economic data, not just the technical possibilities.

Well see than whether it takes a standing army of 10,000 persons to keep a seven-person "fully and rapidly reusable" (Elon's objective) vehicle flying just four flights per year to the ISS. 

I doubt it.

YMMV.

But we'll see, in ten years.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/30/2014 08:10 pm
The actual issue was that I had read that Dracos can't be used in atmospheric conditions. This was why SpaceX had to use a vacuum chamber for acceptance testing of the Dracos. I didn't quite understood why, and since Elon stated that v2 Dracos were improved and used for pinpoint accuracy, either the old information was wrong or this new ones can be used in atmosphere.

Note the word "acceptance".  Since the original Dracos were designed to be used *in orbit* by Dragon v1 to maneuver around the ISS, they have to be tested in those same conditions before it can be certain they will work *in orbit to maneuver around the ISS*.  That doesn't mean they won't work at sea level -- just that it didn't (at the time) make any sense to test them at sea level, since the conditions in which they were to be used were much different.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/30/2014 08:11 pm

By sheer dumb luck, the third stage on that flight didn't break or spin, and so they got away ok.

Had the problem become more severe, which it had every chance to do, they would have died, where an LAS system would have saved them.

Again, you look at a set of circumstances that worked out ok at the end, and infer that therefore an LAS was not needed.

Wrong again,  the system is designed to separate the spacecraft from the third stage using engines at the same time an LAS would separate and fire.  however, the extra acceleration of the LAS is not needed at that point in flight.

The last sentence could not be more wrong.  The LAS is jettisoned because there are other methods of abort and it is not needed.

Jim - the core issues, again:

How does the SM, which has a large, fragile, flight-critical engine bell sitting right between itself and the exploding stage, and can only accelerate at 0.25 g, how does it get away from an exploding upper stage?

How are 8 high-power hypergolic engines, arranged in redundant pairs around and behind the heat shield, not superior to that?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/30/2014 08:13 pm
Also 10+ years of space and combat vehicle design. As well as pilot. I also reacted to the design by flinching.

Some comments about the display and control concept (10 years experience in aircraft cockpits speaking here)
1) The displays may be subject to considerable vibration and may need to have a middle support for the large span all of which may have or need some vibration isolation or control in the mounting.
Launch and descent have severe vibration, oscillation, and turbulence phases. Could not see how the panel could be supported or used rigidly. Wondered if it was only meant to be retracted in those phases, and deployed/used on orbit. But even then the thrusters will oscillate/vibrate it for long burns (short ones the fly by wire control system can modulate/pulse/taper off to make proportional control).

2) The idea that anyone is going to reach up and touch the displays during launch or any other significant acceleration or deceleration is unlikely. This makes them displays only during those phases, but can be controls in other phases of flight like zero gee.
Yes. I'd also be very nervous with this big thing thrashing around over my head in launch/descent.

Your control of the vehicle in these phases are very limited in terms of options, so you are mostly passive. Exception is forced abort on launch - "I want out of here!".

The fear with Apollo/Gemini on orbit for why you want controls on the side (or near body) is like with Neil Armstrong faced with a stuck thruster - you're having to ride a sick control system and work out how to regain control of the vehicle. Test pilots faced this all the time. At a NASA center, I witnessed in the 70's a test program to autonomously do this with a single button press that in less than a second, sort out the control system and stabilize to zero spins/torques all axis, such that non-test pilots could fly a vehicle however compromised. Perhaps they don't need side controllers because of this?

You still need them in combat aircraft because you can't anticipate the means to regain control with what hasn't been shot away.

3) I expect the joystick will have to be lowered to the arm-rest otherwise even in zero Gee if the pilot is controlling the vehicle, thrust will feed back into unintended arm movement and a pilot induced oscillation (PIO) could occur. That is why joysticks are typically adjacent to the arm rest.

The placement of the stick really bothered me, along with Musk's insistence that the right command seat he was in was the pilot's seat (typically that's the copilot's) and that the controller was to his left. Having been in the ARC Apollo flight simulator in N-210, I was expecting a similar arrangement of side controllers and command module pilot (CMP) seat on the left.

4) The primary question about this collection is, are they pilots (having actual control of the vehicle, participating in emergency recovery, guiding the vehicle in phases some phases of flight), or are they passengers? If they are pilots, they may need back-up instrumentation in the event of a full-panel display failure. Displays do fail, and even all the displays can go dark due to single point power connections failure, failure in the graphics distribution/cabling, etc. This has happened a pilot friend of mine doing ferry flight of a 767 after maintenance. That is why most air vehicles have back-up instruments that tend to be mechanically driven or at least electro-mechanically driven.  I might expect these back up instruments to be centered between the two seats. Conveniently, the SpaceX logo occupies the ideal location for that instrument collection. The large SpaceX logo is nice for marketing, but is actually a waste.  I would hope back-up instruments could be placed at that location in future vehicles or updates to this one.
Could they just believe that its pilot/copilot separate systems, and ground control is the final backup?

5) Having redundancy of controls is a useful concept. The displays might benefit from having a remote display control device that the pilots can move across the displays. Computer users with touch screens might understand this as having a mouse in addition to the touch screen. Pilots are familiar with the Hands on Throttle and Stick (HOTAS) concept which provides for cursor controls, display selection using a number of stick mounted buttons. The stick would be the joystick shown, but in modified form.  This may not be necessary, but is could be a useful addition to reduce other concerns. I have attached an image from a commercial game joystick for example that models a relatively modern fighter stick and throttle.
Note - the Apollo side controllers, and Shuttle ones, are considerably different from these - check them out. Work much better for translation.

6)  The graphics shown and the text shown on these screens may be notional. Text may have to be larger to remain readable in high vibration environment of launch and return. Graphic elements that act as buttons or controls on touch screens tend to be larger than a desktop mouse environment to be effective.  I would expect these elements to be around 1.5 to 2 inches across.
Agreed. Also, the displays are sized for importance to the flight/mission phase, and they might change dynamically to reduce the pilot information overload and fatigue requirements.

Also, lack of guards on the switches/buttons also bothered me. Would also have expected such controls to have a "lock-disengage-select-lock-engage" mechanical function. Saw none of that.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Malderi on 05/30/2014 08:13 pm
Given that increasing solar array area would be extremely difficult, that means that hopefully SpaceX has large power margins and/or high confidence in the power requirements of the various subsystems. If they do not, then increasing load will be a matter of increasing weight significantly in the SM with larger batteries or reducing free-flight time. The systems engineers will have their hands full on that one.
I think the number given was 7 days. That seems plenty.

Agreed, 7 days should be. My point is that if power requirements grow over the next several years (or even from upgrades after first flight), your choices are either increasing SM mass (and probably volume/packing considerations), or shortening that from 7 days. Maybe 7 days is where their margin is, and 6 days is totally fine, and they're 100% okay with a 6-day (or 5-day or whatever) orbit lifetime. Just an observation that those trades will be important - batteries are really not mass/volume efficient, even for someone that owns Tesla. :-)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/30/2014 08:13 pm
AFAIK, that happened to a Soyuz, I remember reading on the forum some months ago.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39
Thanks! That is a good example on how a LAS is important all the way to orbit.


Wrong, that shows the opposite that an LAS is not needed all the way to orbit, because the spacecraft thrusters can provide the same role later in the mission. (this only applies to non integral abort systems.)
And by "thruster" I presume your referring to the main engine on the Apollo Service Module, Gemini SM and Soyuz SM?

A main engine that Dragon does not have  to begin with.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: plank on 05/30/2014 08:19 pm
Let Go SpaceX.  ;D  Loving the new spaceship all though I'm not really felling the new trunk design. You would think that since SpaceX is making reusable rockets the trunk would be integrated into the design atlest.  :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: adrianwyard on 05/30/2014 08:21 pm
There are also some abort-related questions on the landing phase:

As expected, Elon said in the case of a propulsive landing abort (say the SuperDracos fail their test firing for some reason) the chutes are deployed. But what sort of a landing can the crew expect?

Some possibilities:
a] It will be a hard landing (similar to that on Soyuz if the landing rockets failed) but it will be survivable and that's what counts. Some injuries allowed.
b] The chutes are big enough to make a land-landing gentle.
c] The Dragon is initially headed for water, but diverts to land when under SuperDraco power, so a chute landing is in water.
d] The legs are designed to crumple and so handle hard-landings under the chutes.
e] The landing pad is designed to somehow mitigate hard landings.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/30/2014 08:21 pm
While we're on the discussion of aborts. Even IF the Spacecraft's engines couldn't thrust fast enough - to avoid re-contact (what was/is the nominal acceleration profile of the Apollo/Soyuz 2nd stage when it's firing?) and even if the spacecraft engine bell was damaged - the heat-shield isn't exposed - being shielded itself, by the service module and the engine bell. Moreover, the capsule's designed to take some MMOD punishment. If you're picturing big scraggy pieces of tank pretty much impaling the capsule with a vengeance, then yes... there's probably not enough MMOD shielding for that macabre situation. But... these tanks are designed with a requirement to be blown up by RSO. Presumably, that requires it to shred into pieces that won't be flung toward the capsule in the case of a termination. The stress of the expanding gas front is surely less than that experienced at entry-interface. As for tumbling and non-optimal orientation of the space-craft... that affects ALL LAS equally. It's not like the SuperDracos can gimbal. Directional thrusting won't help with the moment of detachment. Any attitude steering later will use the RCS?



Also, I think Jim's point about the minimal additional benefit of the LAS wasn't that the LAS was not needed as you climbed in altitude, but that the spacecraft thrusters took over that function, and served as a lighter system capable of giving you the same abort performance. Hence, no need to carry the tower (and extra weight) any higher than they did.

The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.

1. By that logic, the Cupola is criminal. There is such a thing as crew morale.
2. Mike Foale, Valery Korzun Vasily Tsibliyev and Sasha Lazutkin apparently have something to say about that.

Humans literally develop with an oval window in their hearts. And there's one in your head (http://en.wikipedia.org/wiki/Foramen_ovale) and another one in your ear (http://en.wikipedia.org/wiki/Oval_window). It's part of who we are. So it's natural that it would find its way into what we make. (Especially given that the no-corners shape doesn't introduce any structural problems, and, as someone else said, the window allows good downrange visibility - along the major axis - during docking)


Quote
- Quick test shows my smartphone is eminently capable of distinguishing between hardware bumps and intended pushes or slides. Likely by the acceleration profile alone, which is also how some softwares distinguish individuals. (Admittedly from longer interaction, often writing tasks, but affirming the principle.)

As I understand it SpaceX has freedom to choose the technology, and reusing Tesla technology (like for the batteries) would be their rapid development, cheap production pathway. I therefore assume we saw all the controls there ever will be.

Orion is going to be going BEO, through the Van Allen belts, and staying outside them. If something goes wrong, it's not a quick ~hour ride back to safety. They've to be able to fix that stuff there. Neil and Buzz would still be on the moon if they'd used touch-screens and the software broke. That said, I'm not against introducing modern technology. NASA has that freedom too.. but they'd rather let SpaceX qualify the modern technology on SpaceX's dime - if the latter are willing to do it anyway. Plus, if two things are going to weigh the same, then I'd pick a redundant system that doesn't share failure modes with my backup. I'd duplicate only IF such a system was unavailable, or much heavier. Extra-wiring + mechanical switches (for critical functions) cost ~< mass of more touch screens.

The point about hypergols is their carbon, hydrogen, oxygen and nitrogen. So they go to varying mixtures of nitrogen, water, carbon dioxide.

It's the hypergols that are chemical weapons grade toxic not their combustion products.

Yeah, but I think the doubt was whether we could assure complete stoichiometric combustion? Remember those brown clouds that spout sometimes from a Proton launch?


Question:

Can v2's initial (or even all) landings use the parachute WITH propulsive deceleration? We've seen that the SuperDracos can pulse rapidly... So use that, as well as the minimal cross range component of thrust to "fly the canopy"? If you kept the T/W <1 for most of the time, you could do this couldn't you? This way, you have an ALL-OUT capability - and no altitude floor for safe descent.

PS - Scrolling to, and clicking the reply button on SpaceX threads is probably as hard as pressing a small touch-screen button during ascent. The traffic is TOO DAMN HIGH :D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/30/2014 08:29 pm
Can v2's initial (or even all) landings use the parachute WITH propulsive deceleration? We've seen that the SuperDracos can pulse rapidly... So use that, as well as the minimal cross range component of thrust to "fly the canopy"? If you kept the T/W <1 for most of the time, you could do this couldn't you? This way, you have an ALL-OUT capability - and no altitude floor for safe descent.

I believe some of the initial dragonfly tests are listed as rockets + parachute.  So, probably the answer is yes.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/30/2014 08:33 pm
It may have to do with expansion ratio. Dracos have very high expansion ratios for operation in vacuum, and testing a highly expanded vacuum nozzle at atmospheric pressure can be problematic. Also, the Draco bell is truncated on a steep angle that might also cause problems in an atmospheric test.

By contrast, SuperDraco will have a much lower expansion ratio for operation near sea level, so vacuum tests are not necessary.
You missed the flip side.

Musk said the chamber pressure for SD's is about 1000psi. That's very high for a pressure fed engine (it's higher than the F1 and earlier versions of the RL10. So the nozzle might not have the expansion ratio of a Draco but it's much better than it would be if they used the original chamber pressure of the thruster.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 05/30/2014 08:36 pm
Also 10+ years of space and combat vehicle design. As well as pilot. I also reacted to the design by flinching.

Some comments about the display and control concept (10 years experience in aircraft cockpits speaking here)
1) The displays may be subject to considerable vibration and may need to have a middle support for the large span all of which may have or need some vibration isolation or control in the mounting.
Launch and descent have severe vibration, oscillation, and turbulence phases. Could not see how the panel could be supported or used rigidly. Wondered if it was only meant to be retracted in those phases, and deployed/used on orbit. But even then the thrusters will oscillate/vibrate it for long burns (short ones the fly by wire control system can modulate/pulse/taper off to make proportional control).

2) The idea that anyone is going to reach up and touch the displays during launch or any other significant acceleration or deceleration is unlikely. This makes them displays only during those phases, but can be controls in other phases of flight like zero gee.
Yes. I'd also be very nervous with this big thing thrashing around over my head in launch/descent.

Your control of the vehicle in these phases are very limited in terms of options, so you are mostly passive. Exception is forced abort on launch - "I want out of here!".

The fear with Apollo/Gemini on orbit for why you want controls on the side (or near body) is like with Neil Armstrong faced with a stuck thruster - you're having to ride a sick control system and work out how to regain control of the vehicle. Test pilots faced this all the time. At a NASA center, I witnessed in the 70's a test program to autonomously do this with a single button press that in less than a second, sort out the control system and stabilize to zero spins/torques all axis, such that non-test pilots could fly a vehicle however compromised. Perhaps they don't need side controllers because of this?

You still need them in combat aircraft because you can't anticipate the means to regain control with what hasn't been shot away.

3) I expect the joystick will have to be lowered to the arm-rest otherwise even in zero Gee if the pilot is controlling the vehicle, thrust will feed back into unintended arm movement and a pilot induced oscillation (PIO) could occur. That is why joysticks are typically adjacent to the arm rest.

The placement of the stick really bothered me, along with Musk's insistence that the right command seat he was in was the pilot's seat (typically that's the copilot's) and that the controller was to his left. Having been in the ARC Apollo flight simulator in N-210, I was expecting a similar arrangement of side controllers and command module pilot (CMP) seat on the left.

4) The primary question about this collection is, are they pilots (having actual control of the vehicle, participating in emergency recovery, guiding the vehicle in phases some phases of flight), or are they passengers? If they are pilots, they may need back-up instrumentation in the event of a full-panel display failure. Displays do fail, and even all the displays can go dark due to single point power connections failure, failure in the graphics distribution/cabling, etc. This has happened a pilot friend of mine doing ferry flight of a 767 after maintenance. That is why most air vehicles have back-up instruments that tend to be mechanically driven or at least electro-mechanically driven.  I might expect these back up instruments to be centered between the two seats. Conveniently, the SpaceX logo occupies the ideal location for that instrument collection. The large SpaceX logo is nice for marketing, but is actually a waste.  I would hope back-up instruments could be placed at that location in future vehicles or updates to this one.
Could they just believe that its pilot/copilot separate systems, and ground control is the final backup?

5) Having redundancy of controls is a useful concept. The displays might benefit from having a remote display control device that the pilots can move across the displays. Computer users with touch screens might understand this as having a mouse in addition to the touch screen. Pilots are familiar with the Hands on Throttle and Stick (HOTAS) concept which provides for cursor controls, display selection using a number of stick mounted buttons. The stick would be the joystick shown, but in modified form.  This may not be necessary, but is could be a useful addition to reduce other concerns. I have attached an image from a commercial game joystick for example that models a relatively modern fighter stick and throttle.
Note - the Apollo side controllers, and Shuttle ones, are considerably different from these - check them out. Work much better for translation.

6)  The graphics shown and the text shown on these screens may be notional. Text may have to be larger to remain readable in high vibration environment of launch and return. Graphic elements that act as buttons or controls on touch screens tend to be larger than a desktop mouse environment to be effective.  I would expect these elements to be around 1.5 to 2 inches across.
Agreed. Also, the displays are sized for importance to the flight/mission phase, and they might change dynamically to reduce the pilot information overload and fatigue requirements.

Also, lack of guards on the switches/buttons also bothered me. Would also have expected such controls to have a "lock-disengage-select-lock-engage" mechanical function. Saw none of that.

I'm not sure, but I suspect there may be a mismatch between the sort of specific use cases that SpaceX is envisioning for a modern 2010s space capsule design, with all the capabilities in technology that has over the 1960s-vintage requirements for test pilots to fly the capsule in real time, at multiple phases of the mission, and what might be needed for control of a non-UAV aircraft.

Just a guess, but I'm thinking that autonomous-capable space capsules today really don't need a lot of input from their occupants.  (even though I realize that pilots, and military pilots in particular, will want to be able to fly the thing.)  Of course, they'll need some, and you are quite correct that if G loads and vibration don't allow working the notional controls in the unveil, they'll surely be changed.

Ultimately, SpaceX will build what they need for their private purposes, and they'll of course (quite rightly) want to have on it any set of controls that NASA requirements dictate for the subset of missions they fly with USG astronauts on it.  If NASA wants different controls that would satisfy the USAF pilots association, I imagine NASA will so state that in their requirements, and SpaceX will build to that requirement if they want the carbon-based transport work.   ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: arachnitect on 05/30/2014 08:45 pm
Did they say why the side hatch changed?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 08:50 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/30/2014 08:55 pm
A main engine that Dragon does not have  to begin with.

So they go around in a hyperloop. Propulsive landing -> Hence, integrate the mandatory LAS rather than have a separate, reusable, staged LAS -> hence propulsive landing. All based on the presumption that propulsive landing lowers costs. But hey, Elon's got solid industrial business credentials, and I'm sitting at home typing this on my laptop... so yeah, wait and watch (for a few years) atleast. Lest it be inferred otherwise, I'm rooting for them too!


At a NASA center, I witnessed in the 70's a test program to autonomously do this with a single button press that in less than a second, sort out the control system and stabilize to zero spins/torques all axis, such that non-test pilots could fly a vehicle however compromised. Perhaps they don't need side controllers because of this?

You still need them in combat aircraft because you can't anticipate the means to regain control with what hasn't been shot away.

Are you cheekily referring to aircraft with relaxed static stability? And to a button, pressed by an instructor, that delivers a shock to a student and gets him to take hands off all controls? But seriously that sounds very cool. Details? Why would the mounting a stick on a side help? Is it simply the arm-rest and the stability of the pilot's hand?

Given that increasing solar array area would be extremely difficult, that means that hopefully SpaceX has large power margins and/or high confidence in the power requirements of the various subsystems. If they do not, then increasing load will be a matter of increasing weight significantly in the SM with larger batteries or reducing free-flight time. The systems engineers will have their hands full on that one.
I think the number given was 7 days. That seems plenty.

Agreed, 7 days should be. My point is that if power requirements grow over the next several years (or even from upgrades after first flight), your choices are either increasing SM mass (and probably volume/packing considerations), or shortening that from 7 days. Maybe 7 days is where their margin is, and 6 days is totally fine, and they're 100% okay with a 6-day (or 5-day or whatever) orbit lifetime. Just an observation that those trades will be important - batteries are really not mass/volume efficient, even for someone that owns Tesla. :-)

SolarCity provided solar-panels, forming a Tesla supercharger network in orbit, delivered by and catering to SpaceX vehicles. (Solar panels detach from trunk, and remain in orbit. New dragons rendezvous with solar panels on orbit - for independent orbit operations). When there are no dragons, solar cells transmit energy via microwaves to ground/other space assets.

#NextStepsForElon :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: obi-wan on 05/30/2014 09:07 pm
Also 10+ years of space and combat vehicle design. As well as pilot. I also reacted to the design by flinching.

(Snipped)

3) I expect the joystick will have to be lowered to the arm-rest otherwise even in zero Gee if the pilot is controlling the vehicle, thrust will feed back into unintended arm movement and a pilot induced oscillation (PIO) could occur. That is why joysticks are typically adjacent to the arm rest.

The placement of the stick really bothered me, along with Musk's insistence that the right command seat he was in was the pilot's seat (typically that's the copilot's) and that the controller was to his left. Having been in the ARC Apollo flight simulator in N-210, I was expecting a similar arrangement of side controllers and command module pilot (CMP) seat on the left.

(Snipped)

By long heritage at NASA, the right-hand seat is the pilot's - the left-hand seat is for the Commander. (Even back in Gemini, there was no "copilot" - it was Command Pilot and Pilot.

I would echo the concern about the stick, both in placement and quantity. Spacecraft flight control involves six degrees of freedom, traditionally via two 3DOF hand controllers (rotation inthe right hand, translation in the left.) 6DOF controllers from computer interfaces have way too much cross-coupling to accept in vehicle flight control applications.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/30/2014 09:10 pm
I wonder if landing leg bay is also full of PICA-X, not just the feet pads? I am thinking of Columbia. Any weakness in the heat shield, and plasma gets in, and it's a bad day.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 09:14 pm
I wonder if landing leg bay is also full of PICA-X, not just the feet pads? I am thinking of Columbia. Any weakness in the heat shield, and plasma gets in, and it's a bad day.

There are already gaps in the PICA-X on the existing Dragon - for the 6 trunk attachment points.

And if the design stays as shown yesterday, the leg pad will be made from PIXA-X, and as will the material that is wrapped behind the leg. (around the piston)

I don't think it is a significant problem. Capsules have even flown with hatches in the heat shield before.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RoboGoofers on 05/30/2014 09:16 pm
Also 10+ years of space and combat vehicle design. As well as pilot. I also reacted to the design by flinching.

Some comments about the display and control concept (10 years experience in aircraft cockpits speaking here)
1) The displays may be subject to considerable vibration and may need to have a middle support for the large span all of which may have or need some vibration isolation or control in the mounting.
Launch and descent have severe vibration, oscillation, and turbulence phases. Could not see how the panel could be supported or used rigidly. Wondered if it was only meant to be retracted in those phases, and deployed/used on orbit. But even then the thrusters will oscillate/vibrate it for long burns (short ones the fly by wire control system can modulate/pulse/taper off to make proportional control).
sengage-select-lock-engage" mechanical function. Saw none of that.

When Elon gets out of the seat, he fiddles with a toggle. Watching it again, it's clear that the instrument panel locks into place. I also think the instrument panel looks a lot heavier than it is; the screens and hardware used to drive them, along with redundancy, is probably no more than 5 pounds, and i'm sure the panel body itself is carbon fiber and as light as can be.

as for the lack of button fail safe guards, there are many ways to make the buttons fail safe without having to need guards. maybe a rapid triple-click, or using multiple buttons like ctrl-alt-del, or use  separate 'arm' and 'confirm' button
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/30/2014 09:23 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 09:28 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Herb Schaltegger on 05/30/2014 09:31 pm
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

Two in the same "pod" or "fin" or whatever you call it may be an unsurvivable point on the curve but we just don't know.  Alternately, it's conceivable that perhaps just this possibility was one of the drivers to mount the SuperDraco "pods" in the X-configuration rather than the more tradition 90º cardinal points. Perhaps they can use differential throttling, combined with whatever marginal deceleration a late 'chute deploy provides, to create a survivable hard landing, even at the cost of loss of capsule.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/30/2014 09:32 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

Sure, it would be hard to recover from. But so would a stuck aerodynamic surface on a winged craft, and so on. You retire as much risk as you can, but life is not risk free.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/30/2014 09:34 pm
6)  The graphics shown and the text shown on these screens may be notional. Text may have to be larger to remain readable in high vibration environment of launch and return. Graphic elements that act as buttons or controls on touch screens tend to be larger than a desktop mouse environment to be effective.  I would expect these elements to be around 1.5 to 2 inches across.
I can't comment for the rest of your post but I do recall that NASA has standards for text and graphics for size and color and contrast.

While flat panel dot matrix displays can generate pretty much any kind of text and graphics I'm pretty sure they will be sticking to those standards.

I was pretty surprised about some of the other stuff in the presentation given that I thought a number of NASA astronauts had acted as advisers on the cabin layout. The obvious one being the lack of guards over the various switches and buttons, especially when I checked some of the high res pix and saw they controlled some major elements which you'd really want to avoid triggering accidentally.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sublimemarsupial on 05/30/2014 09:36 pm


Also, lack of guards on the switches/buttons also bothered me. Would also have expected such controls to have a "lock-disengage-select-lock-engage" mechanical function. Saw none of that.

The only other crew control hardware SpaceX has put up in orbit is the Dragon CUCU unit in the ISS Cupola robotics workstation - and it has switch guards and such. Either the current controls are a mockup for the media  and all of those practicalities will be added later (likely in my mind), or NASA has said they don't need them (less likely).

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/30/2014 09:39 pm


At a NASA center, I witnessed in the 70's a test program to autonomously do this with a single button press that in less than a second, sort out the control system and stabilize to zero spins/torques all axis, such that non-test pilots could fly a vehicle however compromised. Perhaps they don't need side controllers because of this?

You still need them in combat aircraft because you can't anticipate the means to regain control with what hasn't been shot away.

Are you cheekily referring to aircraft with relaxed static stability? ... Details?
Nope, a spacecraft. Which shall remain nameless. The idea was a coupled inertial platform with a software model that pulsed thrusters to both "learn" the orthonormal translation vectors of the working pattern of thrusters dynamically, then compute an eigenstate of a cancellation burn, then updated with a second order null out of residuals.

As to aircraft, a GA program did develop a similar idea to single button put a aircraft into stable, level flight. Very different control dynamics, and it worked over a much longer interval, because you have to take into account weather/flight conditions. Perhaps you heard about it?

Both were about providing a "reset" button of sorts for a less experienced pilot to recover to a stable, safe state they could take it from there. The first was assuming a emergency, possibly anoxic / hypoxic evac situation, the second was  to make GA safer for "sunday driver" pilots ...


Why would the mounting a stick on a side help? Is it simply the arm-rest and the stability of the pilot's hand?

If you're in a spin/torque situation, you can't move controls further out due to angular momentum, but you can move your wrists to control the craft. You feel like you're wrapped in a blanket, cut off from taking action with your arms pinned.

Worse, you might have multiple planes of such orthogonal, and they couple paradoxically. So when you are on the simulator or craft, you can easily make the situation worse by false moves. You work out of it by damping torques as you re establish stability such that you can comprehensively understand your situation, possibly with external cues.

If the controls are closer to your body CG, you expend more energy with the controls and less fighting to control your body flailing.

You don't need any distractions.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/30/2014 09:41 pm
Some corner case on the SD powered landing would only be a problem if it happens  below minimum altitude for the parachutes to deploy. I don't know where that is, but someone should know. I would hazard a guess around 1000m is the optimal point of no return, but maybe it could be around 500m in the last ditch attempt to survive.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 09:43 pm
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

Two in the same "pod" or "fin" or whatever you call it may be an unsurvivable point on the curve but we just don't know.  Alternately, it's conceivable that perhaps just this possibility was one of the drivers to mount the SuperDraco "pods" in the X-configuration rather than the more tradition 90º cardinal points. Perhaps they can use differential throttling, combined with whatever marginal deceleration a late 'chute deploy provides, to create a survivable hard landing, even at the cost of loss of capsule.
Perhaps a ballistic parachute...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 09:45 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

Sure, it would be hard to recover from. But so would a stuck aerodynamic surface on a winged craft, and so on. You retire as much risk as you can, but life is not risk free.
Lars, you’re a philosopher... ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: astaldaran on 05/30/2014 09:47 pm

SolarCity provided solar-panels, forming a Tesla supercharger network in orbit, delivered by and catering to SpaceX vehicles. (Solar panels detach from trunk, and remain in orbit. New dragons rendezvous with solar panels on orbit - for independent orbit operations). When there are no dragons, solar cells transmit energy via microwaves to ground/other space assets.

#NextStepsForElon :P

If only it was that easy:) This sounds like a scheme from Scott Manning in KSP:)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/30/2014 09:48 pm
Some corner case on the SD powered landing would only be a problem if it happens  below minimum altitude for the parachutes to deploy. I don't know where that is, but someone should know. I would hazard a guess around 1000m is the optimal point of no return, but maybe it could be around 500m in the last ditch attempt to survive.
Maybe someone from SpaceX is reading this and get back to us... :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 05/30/2014 09:57 pm
I think we are beyond the point in avionics technology where anybody realistically expects someone to fly a spacecraft in a truly manual way.    Commercial and military aircraft have been using fly-by-wire flight controls for some time.  At its most basic, manual inputs on any new capsule will go through avionics software.   The systems and automated piloting systems are old, reliable and proven technologies, unlike the Apollo days. 

A lot of powerful, but simplified flight authorities can be selected from touch screens or a 3D joystick.     If that approach doesn't work out in development, then more traditional controls should make their way in.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/30/2014 09:58 pm
Also 10+ years of space and combat vehicle design. As well as pilot. I also reacted to the design by flinching.

(Snipped)

3) I expect the joystick will have to be lowered to the arm-rest otherwise even in zero Gee if the pilot is controlling the vehicle, thrust will feed back into unintended arm movement and a pilot induced oscillation (PIO) could occur. That is why joysticks are typically adjacent to the arm rest.

The placement of the stick really bothered me, along with Musk's insistence that the right command seat he was in was the pilot's seat (typically that's the copilot's) and that the controller was to his left. Having been in the ARC Apollo flight simulator in N-210, I was expecting a similar arrangement of side controllers and command module pilot (CMP) seat on the left.

(Snipped)

By long heritage at NASA, the right-hand seat is the pilot's - the left-hand seat is for the Commander. (Even back in Gemini, there was no "copilot" - it was Command Pilot and Pilot.
Always found that weird. The CMP position in Apollo was, BTW, in the center, with the mission commander on the left and the LM pilot on the right. Comes from AF authority structure, which may not be correct here. If we are making this "commercial" like a airliner her referred to, perhaps NASA heritage isn't the correct metaphor for the two positions.

My point is that clearly there are two pilot positions, possibly mimicking an aircraft, thus the pilot/copliot, if you can get over the fact that your sharing a single control in between with switched sides - for reflex manoeuvres, you'd have to be ambidextrous and trained both ways.

Also, you've now got two other positions surrounding the control positions on the "flight deck", either can be the "commander". So much for blurring PIC!

Admittedly, flying a helicopter requires two hands, two feet, and a tail for the radios/nav, and I don't see any of that either. So it looks like totally automated landing for the flight termination.

As a pilot, I like to maintain proficiency regardless of technology - where would I train for something like this?

Push the button and trust? Not me.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/30/2014 10:11 pm
Also 10+ years of space and combat vehicle design. As well as pilot. I also reacted to the design by flinching.

Some comments about the display and control concept (10 years experience in aircraft cockpits speaking here)
1) The displays may be subject to considerable vibration and may need to have a middle support for the large span all of which may have or need some vibration isolation or control in the mounting.
Launch and descent have severe vibration, oscillation, and turbulence phases. Could not see how the panel could be supported or used rigidly. Wondered if it was only meant to be retracted in those phases, and deployed/used on orbit. But even then the thrusters will oscillate/vibrate it for long burns (short ones the fly by wire control system can modulate/pulse/taper off to make proportional control).
sengage-select-lock-engage" mechanical function. Saw none of that.

When Elon gets out of the seat, he fiddles with a toggle. Watching it again, it's clear that the instrument panel locks into place. I also think the instrument panel looks a lot heavier than it is; the screens and hardware used to drive them, along with redundancy, is probably no more than 5 pounds, and i'm sure the panel body itself is carbon fiber and as light as can be.

It needs to be rigidly anchored at the ends of the panel to the outside of the craft, otherwise it will flex/wobble/warp through modes as the forces on the capsule induce different modes on the panel. Not good enough to constrain with two attachments in the center/edges - at least it will "flap" on the ends.

If its 5 lbs, breaks off at 5G+, its still gonna hut my head :)


as for the lack of button fail safe guards, there are many ways to make the buttons fail safe without having to need guards. maybe a rapid triple-click, or using multiple buttons like ctrl-alt-del, or use  separate 'arm' and 'confirm' button

Then I've a delay or ambiguity in control function. With multifunction switches its muscle-memory reflex like with martial arts, and you can do it while you are being bounced around.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: starsilk on 05/30/2014 10:13 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

gun the remaining engines (or at least, opposed pairs) to push the capsule back above chute deploy altitude. back to using them as a LAS. (Launch/Landing Abort System)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/30/2014 10:13 pm
Nope, a spacecraft. Which shall remain nameless. The idea was a coupled inertial platform with a software model that pulsed thrusters to both "learn" the orthonormal translation vectors of the working pattern of thrusters dynamically, then compute an eigenstate of a cancellation burn, then updated with a second order null out of residuals.

Machine learning? IN THE 70s? Mind = blown. Doing that in real time, with modern computing sounds challenging enough, not to mention measuring the rates themselves.

As to aircraft, a GA program did develop a similar idea to single button put a aircraft into stable, level flight. Very different control dynamics, and it worked over a much longer interval, because you have to take into account weather/flight conditions. Perhaps you heard about it?

This sounds like a rhetorical question lol, but no, I haven't. Should I have?

If you're in a spin/torque situation, you can't move controls further out due to angular momentum, but you can move your wrists to control the craft. You feel like you're wrapped in a blanket, cut off from taking action with your arms pinned.

I was comparing a side with a centre stick, and it didn't seem that you'd have to stretch further... but now I know otherwise.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/30/2014 10:39 pm
Nope, a spacecraft. Which shall remain nameless. The idea was a coupled inertial platform with a software model that pulsed thrusters to both "learn" the orthonormal translation vectors of the working pattern of thrusters dynamically, then compute an eigenstate of a cancellation burn, then updated with a second order null out of residuals.

Machine learning? IN THE 70s? Mind = blown. Doing that in real time, with modern computing sounds challenging enough, not to mention measuring the rates themselves.
Yes, with MSI logic minicomputers. We did a lot that didn't get flown.  Fear of the machine. Some at the time didn't believe in "fly by wire". Same idi ots who told me they could  hear the bits of digital audio and that analog would last forever ...

The "learning" was a limited/bounded nonlinear statistical filter with three samples of a stepped pulse. Inline coded.

As to aircraft, a GA program did develop a similar idea to single button put a aircraft into stable, level flight. Very different control dynamics, and it worked over a much longer interval, because you have to take into account weather/flight conditions. Perhaps you heard about it?

This sounds like a rhetorical question lol, but no, I haven't. Should I have?
It was demonstrated on TV news once. Many saw it. Thought you were referring to it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space OurSoul on 05/30/2014 11:05 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

Elon was careful to say that you can lose "up to" two SDs. I.e. you can lose two as long as they're not in the same pod.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: somepitch on 05/30/2014 11:18 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

gun the remaining engines (or at least, opposed pairs) to push the capsule back above chute deploy altitude. back to using them as a LAS. (Launch/Landing Abort System)

If you throttled up the two remaining opposing pairs for deceleration would the Dracos have enough authority to keep it level for a less precise (but survivable) landing?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/30/2014 11:34 pm
I need some clarity... So landing sequence is SD powered up if you lose more than two, chute deploy.
If you are below safe chute deploy under SD power, what if you lose two on the same corner, will the remaining three sets (corners) be able to stabilize for landing?

As I heard it from Elon's talk:

SD are tested at high altitude. If they work, powered landings are initiated at the appropriate altitude. If they have an anomaly of any kind, the SD landing attempt will be aborted and the chutes will deploy at the appropriate altitude. If they are on a powdered descent, they can still lose two SD's and have a powered landing as the other SD's will compensate.
Yes, that is what I heard as well, but two on the same corner below safe chute deploy altitude is what I need to wrap my head around...

These are effectively ballistic parachutes. There is a decision deck altitude where you make a call on propulsive landing or shut off engines and go for parachute, but there is no "safe chute deploy" altitude. If manure hits the fan below below your decision deck, you simply deploy anyway and pray.
In skydiving, the equivalent ( unlikely ) situation would be your main canopy ripping in half suddenly - you pull your reserve without thinking about it, no matter the altitude.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: adrianwyard on 05/30/2014 11:59 pm
Yes, if in doubt deploy and pray, but the lower you deploy the chutes, the harder the landing. A very hard landing could breach those tanks of toxic hypergolic liquids and add considerable drama...

As I mentioned upthread, even deploying parachutes at a high enough altitude to reach terminal velocity (i.e. minimum) will likely end with a hard landing:

http://forum.nasaspaceflight.com/index.php?topic=34828.msg1207126#msg1207126

In fact the risk of a breach might be high enough that it would make sense to burn off the propellant while descending under parachutes - using whatever thrusters make sense force-wise. And rather than a chutes-only hard-landing, retain just enough fuel to soften the impact with one last big burn. You might be able to achieve that with only two functioning SuperDracos if they were on opposite sides of the vehicle.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/31/2014 12:12 am
Yes, if in doubt deploy and pray, but the lower you deploy the chutes, the harder the landing. A very hard landing could breach those tanks of toxic hypergolic liquids and add considerable drama...

Absolutely, and your once nicely reusable spacecraft is likely designed to be a total writeoff after a hard landing. They'll probably have a nice CDW on it.
But this is an emergency scenario, and the hopefully already low probability of something like that happening should start rapidly decreasing after initial flights and systems are better understood.

EDIT: I meant, i am pretty sure they have designed for the hard landings including last second chute deployment, including crumpling  the legs, the seats etc. 
The exact decision tree for the flight computer acting in emergency mode would be pretty hard to guess as there is a myriad of different situations that could occur - depending on altitude, velocity, failure location and type, too, spin , etc.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: adrianwyard on 05/31/2014 12:18 am
...well rather than an accounting problem I was worried about a deadly explosion and/or fireball.

The good news in the DragonFly test program sounds extensive - tens of flights - so with any luck these emergency scenarios will be tested out and confidence gained (e.g. using whatever SDs remain functional to soften the impact of a parachute land landing).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/31/2014 12:41 am
Thanks for your comments so far everyone about a total SD corner failure below decision height and PD commit...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: robertross on 05/31/2014 02:14 am
In reading through this thread I have noticed some people being  bit too critical of the unveiling (imo).
I think there needs to be some context put on this:

The US is looking for its next downselect to fund commercial crew, and with the political situation brewing with Russia, it is clear that the US is facing a dilema. So what better way to help your own cause then showcase what you re working on?

I'm sure all the other players are feeling jealous and perhaps concerned that SpaceX beat them to the punch - perhaps not with a fully functional crew-capable spacecraft (for which nobody has at this stage), but an actual flight article to showcase.

This is salesmenship to the politicos who make the decisions & write the cheques. Elon knows this, and I am certain the reason for his timing.

As for the spacecraft: lack of interior insulation & padding only helps to 'sell' how roomy the spacecraft looks on the inside. It also helps to show the amount of available space for cargo should a full crew complement not be there (as has been noted on here), and likely helped him get in & out of the seat (for which getting out of actually did cause a slight issue, but that's nothing, especially when you see a crew extraction from Soyuz after 6 months in space: they will all need help coming out of their seats).

Solar array design, radiators, fins, docking covers, oval windows: these are the concepts to be proven out in the testing phase. What really matters is they have a pressure hull, SuperDraco engines, and a safety system concept (with working heritage from Dragon V1).

The display screen is a great concept, but I too have concerns about strength at G forces. But if there is an issue, SpaceX will obviously re-design it, like so many things that get changed in this business. I saw it more as a great 21st century concept, and hope they can make something like that work, even if it is re-designed many times.

Another big plus is that they have a financial backer willing to put his own money into this to get things moving. So many companies (specific heavy-weights too), are interested more in the bottom line and year end profits for shareholders, hoping to win out on another government contract with serious lobying behind the scenes, that they fail to take the long view and should be more concerned with being forward-thinking and reaching for the next technology even if government funding isn't there.

SO let's all be happy that SpaceX is taking the initiative with some forward-thinking concepts, getting the word out there, being bold (as if they haven't been doing a good job at that since the start), and trying to get the US back into launcing its people into orbit with domestic capabilities.


Disclaimer: Although I am fully happy with SpaceX progress & acheivements, I am no 'fan-boy'. I just love spaceflight, this site, and want everyone to succeed in market that I believe has room for all (or at least many) of them.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 05/31/2014 02:19 am
Full transcript of the unveiling (http://shitelonsays.com/transcript/spacex-unveils-dragon-2-2014-05-29) and of the Q&A (http://shitelonsays.com/transcript/spacex-dragon-2-unveil-qa-2014-05-29).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/31/2014 02:27 am
Garrett Reisman says Dragon 2 will do same-day ISS flights instead of 3 days.

From the pic below, there's a ton of headroom in there too.

http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA (http://"http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA")

Quote
>
Reisman said SpaceX is aiming to launch crews on Dragon spacecraft and complete an autopilot docking with the International Space Station on the same day.
>
>
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mongo62 on 05/31/2014 02:59 am
Regarding loss of both Superdracos in the same pod, it appears that the Superdracos are massively overpowered for their jobs, and by total thrust alone, could lose at least half their number and still have sufficient remaining thrust to complete a successful landing. So if both Superdracos in a pod were to fail, why not shut down both opposing Superdracos and double the thrust level of the four active Superdracos? Would differential throttling of the remaining Superdracos (plus perhaps use of the Draco thrusters) provide sufficient control authority to allow for a soft touchdown?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: somepitch on 05/31/2014 03:59 am

I'm sure all the other players are feeling jealous and perhaps concerned that SpaceX beat them to the punch - perhaps not with a fully functional crew-capable spacecraft (for which nobody has at this stage), but an actual flight article to showcase.
Blue Origin flew something not too much different than the Dragon v2 mockup as early as 2007.  I think SpaceX is playing catchup, but they have a high popularity coefficient that is graphed using the formula P=(gt^2)/radius of the earth.

Blue Origin has been relatively low key/secretive. But you can find a few of their videos on YouTube.

Just an opinion, but perhaps SpaceX takes the lead if they put a crew into Dragon v2 and go fly.  I don't think Blue Origin has done anything manned, but they probably want to.  I'd guess SpaceX is five-seven years out to flying a manned Dragon v2 (based on how long it takes to develop an experimental aircraft under the FAA).  One year out seems too sporty.


Ummmmm I'm pretty sure that vehicle hasn't been anywhere near space yet, whereas V2 has a solid lineage of space-proven technology behind it.  Sure SpaceX gains a bit of attention due to popularity, but to say they're playing catch-up to Blue Origin...?

If SpaceX is 4-6 years off in their predictions of having a manned V2 ready as you say, given where they've got to already with Dragon, that will be indicative of faaaar more serious issues with the company, and manned spaceflight will have become the least of their concerns IMO...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/31/2014 04:01 am
The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.

"No... no window? What about the hatch?"

https://www.youtube.com/watch?v=C-qEmmpGYvA
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Darkseraph on 05/31/2014 04:05 am
Garrett Reisman says Dragon 2 will do same-day ISS flights instead of 3 days.

From the pic below, there's a ton of headroom in there too.

http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA (http://"http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA")

Quote
>
Reisman said SpaceX is aiming to launch crews on Dragon spacecraft and complete an autopilot docking with the International Space Station on the same day.
>
>

In some cases it will even do same-hour flights to the Atlantic ocean!!  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/31/2014 04:10 am
Regarding loss of both Superdracos in the same pod, it appears that the Superdracos are massively overpowered for their jobs, and by total thrust alone, could lose at least half their number and still have sufficient remaining thrust to complete a successful landing. So if both Superdracos in a pod were to fail, why not shut down both opposing Superdracos and double the thrust level of the four active Superdracos? Would differential throttling of the remaining Superdracos (plus perhaps use of the Draco thrusters) provide sufficient control authority to allow for a soft touchdown?

While there would likely be enough thrust, without the other SDs you would have almost no roll and/or translation capability. Dracos don't have that much thrust - a slight breeze might overpower them.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ThereIWas3 on 05/31/2014 04:16 am
Push the button and trust? Not me.

It used to be that elevators required trained operators.  I can remember those.  A manual lever
controlled speed and direction.  Bringing the car to a gentle stop, with the floor of the car
matching that of the floor outside the door, was entirely up to the training of the operator.

Now you just get in, push the button, and trust.  Even though you are still in a little box suspended
over a drop of possibly hundreds of feet.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/31/2014 04:36 am
It used to be that elevators required trained operators.  I can remember those.  A manual lever controlled speed and direction.  Bringing the car to a gentle stop, with the floor of the car matching that of the floor outside the door, was entirely up to the training of the operator.

Now you just get in, push the button, and trust.  Even though you are still in a little box suspended over a drop of possibly hundreds of feet.

Except in the Capitol Building in Sacramento, California where the administration refused to end the  sinecures of the elevator operators for thirty full years after the installation of automatic elevators in the building, until 2008 under Schwarzenegger. (Don't blame me, I voted for McClintock.) The inertia of large organizations can be staggering.

(http://www.newsreview.com/imager/going-up/b/original/44089/0a47/fifteen-16629.jpeg) (http://www.newsreview.com/sacramento/going-up/content?oid=44089)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/31/2014 07:16 am
These are effectively ballistic parachutes. There is a decision deck altitude where you make a call on propulsive landing or shut off engines and go for parachute, but there is no "safe chute deploy" altitude. If manure hits the fan below below your decision deck, you simply deploy anyway and pray.
In skydiving, the equivalent ( unlikely ) situation would be your main canopy ripping in half suddenly - you pull your reserve without thinking about it, no matter the altitude.

This holds for Dragon (and airframes that don't produce substantial lift at low speeds), but not necessarily for all ballistic parachute systems. If you're already below the minimum altitude (and concomitantly, above the maximum speed) that would allow your parachute to deploy and bring you to the ground - you might actually be reducing the lift you're getting from your (possibly damaged) aircraft - depending on the geometry and attitude changes caused by a ballistic recovery system deployment. It might've been better to not deploy, and use whatever control authority you had to perform an aerodynamic manoeuvre that reduced your vertical speed at the last instant. Relevant if they're going to put a BRS on Dreamchaser maybe.

It used to be that elevators required trained operators.
...
Now you just get in, push the button, and trust.  Even though you are still in a little box suspended
over a drop of possibly hundreds of feet.

This isn't a fair comparison. Almost no one complains about the use of auto-pilot on commercial flights - but everyone would be up in arms if airlines didn't carry a crew for emergency situations. It's augmenting and complementing, not substituting. As regards the elevator - the emergency brakes used are still very similar to Otis' original. Entirely mechanical, and designed to not require human intervention from the very first iteration.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CJ on 05/31/2014 10:26 am
I'd like to start off by thanking Quantum G for the links and transcripts, and also thanking Helodriver for the incredible pics, firsthand account, and for asking great questions.

I hope, going forward, that the pad abort and MaxQ abort tests go well, and are fairly soon.

The first orbital flight will probably be unmanned, and I have a very strong hunch that there will be cheese. :)



   
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: malu5531 on 05/31/2014 10:34 am
The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.

"No... no window? What about the hatch?"

https://www.youtube.com/watch?v=C-qEmmpGYvA

I love that scene! :) I wonder which way SpaceX will go? It seems to me they are moving towards fully automatic flight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/31/2014 11:17 am
I think we are beyond the point in avionics technology where anybody realistically expects someone to fly a spacecraft in a truly manual way.    Commercial and military aircraft have been using fly-by-wire flight controls for some time.  At its most basic, manual inputs on any new capsule will go through avionics software.   The systems and automated piloting systems are old, reliable and proven technologies, unlike the Apollo days. 
Funny you should say that as the first NASA experiments with an unstable aircraft kept stable by a computer with the pilot only requesting control surface motion was done with a left over Apollo Guidance Computer, as that was the most reliable computer they could find (that they could afford  :))
Quote
A lot of powerful, but simplified flight authorities can be selected from touch screens or a 3D joystick.     If that approach doesn't work out in development, then more traditional controls should make their way in.
I think it's the idea that pilots develop a bunch of reflexes that relate their spacial awareness to what they want to do.

Basically its the difference between playing a game on a console with the right hand controller and playing it on your mobile.

Quote
as for the lack of button fail safe guards, there are many ways to make the buttons fail safe without having to need guards. maybe a rapid triple-click, or using multiple buttons like ctrl-alt-del, or use  separate 'arm' and 'confirm' button

Then I've a delay or ambiguity in control function. With multifunction switches its muscle-memory reflex like with martial arts, and you can do it while you are being bounced around.
I think this may be the problem.

Some people think this an interface to computer software that connected to "stuff."

Some people think it's a flight control system that happens to have an embedded computer behind it that makes it work.

In transport vehicles the UI is actually a major part of the design. It's so standardize for most vehicles you don't actually realize there is one. For example some early cars had rudders, not steering wheels, as their developers thought that was more "intuitive." Likewise I doubt any American could actually start a Ford Model T without being shown first or reading the manual.

Despite the astronauts claimed input to the design I'd say Spacex still think of this as a UI for some software, and I think that's a wrong approach.

Either this is a vvery early development model or there are likely to be a few complaints at launch.  :(

"No... no window? What about the hatch?"
I love that scene! :) I wonder which way SpaceX will go? It seems to me they are moving towards fully automatic flight.
I'd forgotten what a good collection of actors were in "The Right Stuff."

Another part of the US Space programme that Ed Harris has been in.  :)

But to return to topic..
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/31/2014 11:24 am
Full transcript of the unveiling (http://shitelonsays.com/transcript/spacex-unveils-dragon-2-2014-05-29) and of the Q&A (http://shitelonsays.com/transcript/spacex-dragon-2-unveil-qa-2014-05-29).
Is that really a Q&A? I got the sense it was more some additional "after presentation" remarks expanding on the presentation.

Just my impression.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/31/2014 11:35 am
Garrett Reisman says Dragon 2 will do same-day ISS flights instead of 3 days.

From the pic below, there's a ton of headroom in there too.

http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA (http://"http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA")

Quote
>
Reisman said SpaceX is aiming to launch crews on Dragon spacecraft and complete an autopilot docking with the International Space Station on the same day.
>
>
I could not get the direct linke to work but found the page eventually. Good point about about the 1 day to ISS trajectory. Also the "artists impression" seems to confirm that "flattened" top I though I saw in the unveiling.

I expect D2 will have a lot better L/D than D1.

BTW 7 day endurance + solar top up on trunk + high power engines with enough fuel --> Apollo 8 cirumlunar flight?

Just a thought.  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mlindner on 05/31/2014 11:47 am
The discussions on this site are fueled off information, and there's nothing better than that which arrives straight from the horse's mouth, so to speak. I wish Elon had shared more detail regarding this amazing piece of work.

I imagine so do... Boeing... the Chinese... Roscosmos...  etc.

I'm cool with what we got.

Certainly, Lar. But indulge me a few examples, however trivial:

1. There wasn't a mention of the fins on the trunk. Yet they're entirely new for D2, and they look kinda cool. Why not point them out to the public? What would the act of doing so have told the Chinese?

2. Elon hops into a capsule that clearly has one row of seats, having just claimed it can seat seven. How about a simple: "Check it out, our seating configuration is flexible. We thought of that, look at us."

3. Sweet leather chairs, as seen in the teaser image on SpaceX.com. Elon, were they designed by your boys at Telsa? No idea. Not a word about them.


Guys, I'm not bashing SpaceX here. I wish Elon's presentation had tooted SpaceX's horn even more. They are in, what seems to me, a delicate time what with CCiCap down-select on the horizon, and of course the ULA lawsuit.

I just want this company to put its best foot forward.   :-\

2. You didn't watch very closely. There's very clearly 2 rows of seats.

There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected. No politician would push for it and they wouldn't lose it on technical merit. It's more a question of "if two companies are chosen, who's the other company?"
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Burninate on 05/31/2014 12:14 pm
Garrett Reisman says Dragon 2 will do same-day ISS flights instead of 3 days.

From the pic below, there's a ton of headroom in there too.

http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA (http://"http://spaceflightnow.com/news/n1405/29dragonv2/#.U4k5acvD_qA")

Quote
>
Reisman said SpaceX is aiming to launch crews on Dragon spacecraft and complete an autopilot docking with the International Space Station on the same day.
>
I could not get the direct linke to work but found the page eventually. Good point about about the 1 day to ISS trajectory. Also the "artists impression" seems to confirm that "flattened" top I though I saw in the unveiling.

I expect D2 will have a lot better L/D than D1.

BTW 7 day endurance + solar top up on trunk + high power engines with enough fuel --> Apollo 8 cirumlunar flight?

Just a thought.  :)
>

Shotwell said explicitly that the Falcon Heavy was a lot smaller than they'd need to launch crew to the Moon or Mars.

Perhaps a no-landing lunar flyby + return from a Crew Dragon 2.0 via Falcon Heavy, launched with 4 seats, extra life support(chapter 7: Space Toilets), and a Propulsion Module in the trunk, could work,  if such a mission wasn't seen as pointless.  Or launch it with 7 people and a genuine habitation module attached to the front, but that's a whole other conversation.

Could we find two people willing to pay $200M each to perform a lunar flyby as passengers in a closet-sized volume?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/31/2014 12:35 pm

There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected. No politician would push for it and they wouldn't lose it on technical merit. It's more a question of "if two companies are chosen, who's the other company?"

Unsubstantiated.   What technical merit?  You have no insight into the workings of the vehicle.  What "public"?  They wouldn't care except for the amazing people?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Garrett on 05/31/2014 12:58 pm
Some people are looking for the parachutes on Dragon v2 (were they included in the v2 design?  Donno?). 

There will be design changes from what we saw a couple days ago to what will eventually fly.
Parachutes included in v2, mentioned by Elon. V2 parachute drop test also completed.

No more significant design changes. Integrated critical design review completed in April. They're on the home stretch now.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Blackstar on 05/31/2014 01:16 pm
There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected.

Can you cite the last space-related riot? I cannot remember any.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/31/2014 01:45 pm

There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected. No politician would push for it and they wouldn't lose it on technical merit. It's more a question of "if two companies are chosen, who's the other company?"

Unsubstantiated.   What technical merit?  You have no insight into the workings of the vehicle.  What "public"?  They wouldn't care except for the amazing people?
I agree with Jim; the general public doesn't care about space.  NSF represents a cross section of propeller heads err... space enthusiasts *some of whom still have slide rules and actually had propeller beanies -NSF doesn't represent the general public.
If today a down select were forced by congress to a single provider the choice would go to CST100(Orion) because that program has the political momentum to sustain it.
NASA doesn't want to down select, and hopefully this won't happen for a few years, but a down select may occur sooner if the ISS goes away in 2020. That is my real fear but my arms are tired.



Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mr. mark on 05/31/2014 01:56 pm
One thing not considered is that some of the spacecraft internals might be company propritary and SpaceX might not want them shown at this point. Just a thought. So we may not really know how far they are along in the process.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/31/2014 02:10 pm
Some people are looking for the parachutes on Dragon v2 (were they included in the v2 design?  Donno?). 

There will be design changes from what we saw a couple days ago to what will eventually fly.
Parachutes included in v2, mentioned by Elon. V2 parachute drop test also completed.

No more significant design changes. Integrated critical design review completed in April. They're on the home stretch now.

Awesome! (You are saying they secretly flew v2 and it worked)...

Garret said that V2's parachute system has been tested.

Helicopter drop. It was publicised, complete with pics / video. Definitely not secret.

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 05/31/2014 02:16 pm

There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected. No politician would push for it and they wouldn't lose it on technical merit. It's more a question of "if two companies are chosen, who's the other company?"

Unsubstantiated.   What technical merit?  You have no insight into the workings of the vehicle.  What "public"?  They wouldn't care except for the amazing people?

Why the frequent resort to ad hominem argument, Jim? 

Don't you realize that such arguments are fallacious (http://c2.com/cgi/wiki?FallaciousArgument)?  ... and lead to you being taken less seriously than if you engaged in standard rhetoric.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/31/2014 02:29 pm

Why the frequent resort to ad hominem argument, Jim? 

a.  I did not call him a fanboi.
b.  The statement stands.  The general public couldn't care less except for a small segment that doesn't use logic that make their choices.
c.  he made a claim that isn't based on any relevant data

So show me the ad hominem part of the argument?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mmeijeri on 05/31/2014 02:33 pm
There is always some injury with ejection.

Always some injury or always some risk of injury?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Herb Schaltegger on 05/31/2014 02:33 pm

There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected. No politician would push for it and they wouldn't lose it on technical merit. It's more a question of "if two companies are chosen, who's the other company?"

Unsubstantiated.   What technical merit?  You have no insight into the workings of the vehicle.  What "public"?  They wouldn't care except for the amazing people?

Why the frequent resort to ad hominem argument, Jim? 

Don't you realize that such arguments are fallacious (http://c2.com/cgi/wiki?FallaciousArgument)?  ... and lead to you being taken less seriously than if you engaged in standard rhetoric.

Is it ad hominem to point out a poster's clear lack of knowledge of a subject? People who DO work in the field, or used to do so in a capacity relevant to the points being discussed, have earned the right to call BS when they see it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: kevinof on 05/31/2014 02:34 pm
Was looking a video posted maybe yesterday by someone here on the ISS and they had a "tour" of the Soyuz. I never realised how small and cramped they are. Would do my head in to be stuck in one for a couple of days.  Dragon 2 is positively huge in comparison. And yes I do realized there are 2 parts to the Soyuz but still.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IslandPlaya on 05/31/2014 02:35 pm
The ad hominem part was you claiming he had "no insights of the working of the vehicle"
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/31/2014 02:37 pm
The ad hominem part was you claiming he had "no insights of the working of the vehicle"

That would be ad hominem only if insights of the working of the vehicle would be irrelevant to the argument at hand.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IslandPlaya on 05/31/2014 02:39 pm
Which of course we have no insights to the vehicles internal working. Hence a strawman argument.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 05/31/2014 02:42 pm
Which of course we have no insights to the vehicles internal working. Hence a strawman argument.

Wrong. No one here has the insights to the workings of any vehicle to make such a judgement that Spacex should win based on technical merit. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IslandPlaya on 05/31/2014 02:47 pm
Granted. I like your use of unsubstantiated now... I think I'm finally coming round to your way of thinking!
You maybe could be a bit more verbose and explain yourself to us noobs though!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/31/2014 03:14 pm

There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected. No politician would push for it and they wouldn't lose it on technical merit. It's more a question of "if two companies are chosen, who's the other company?"

Unsubstantiated.   What technical merit?  You have no insight into the workings of the vehicle.  What "public"?  They wouldn't care except for the amazing people?
I agree with Jim; the general public doesn't care about space.  NSF represents a cross section of propeller heads err... space enthusiasts *some of whom still have slide rules and actually had propeller beanies -NSF doesn't represent the general public.
If today a down select were forced by congress to a single provider the choice would go to CST100(Orion) because that program has the political momentum to sustain it.
NASA doesn't want to down select, and hopefully this won't happen for a few years, but a down select may occur sooner if the ISS goes away in 2020. That is my real fear but my arms are tired.

And don't pretend that all of you old hands really know whats up either. Some of you consistently cross the line and are bullies - especially to people who are clearly not industry insiders. Keep patting yourselves on the back for a lot of jargon and exclusive banter.

I just want to voice some defense for those of us who don't spend our holidays with a slide rule.
My goodness, do I owe an apology for stating potential political outcomes?
Space politics is yucky, but that's where the money comes from to do wonderful and exciting things such as Dragon V2. Reality is what it is.
Spend a holiday or lifetime learning how every element of your tablet or pc works. Grok your tools.
How could life be satisfying without an understanding of how things work?
Some of us old farts really do understand modern manufacturing engineering methodology, project and enterprise management because we invented the technology as soon as the microprocessor became available.
Consider the EOS laser sintering system used in constructing an inconel engine.
http://www.eos.info/en (http://www.eos.info/en)

We have done a 100 things you cannot dream of and the collective result of our engineering efforts over the last 30 years are brought forth by new companies such as Tesla and SpaceX which are not burdened by the inertia of ramping up an organization to modern paradigms technology now affords.
That is our legacy to you.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 03:32 pm
Agree. The idea that this presentation indicates they "must" be chosen for commercial crew is absurd.  We saw a flashy craft and one that will no doubt fly...somewhere. But NASA has set the objective of selecting something for ISS they essentially they see as proven, reliable and simple; this craft, In striving to be "revolutionary," proves that they seem to prioritize flash and salesmanship, which may actually hurt their prospects, in the opinion of some. 

There are several technologies here that remain to be flight tested and could well prove problematic, some of which have historically been considered and discouraged, such as hatches in the heat shield.  Lots of flight test work to be done here. Lots of potential for problems to arise in the timeframe available.  So much for being "ahead." 

The amazing peoples say Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction.  While the original ARES mantra of " safe, simple, soon" carries a lot of negative connotations, the fact is, that slogan sums up nicely what NASA was and is seeking in finding an orbital taxi candidate -- a role that candidly is not particularly flashy or complex.  This presentation shows Musk can innovate, but was that what NASA requested?  ( and paid for through the commercial crew process -- something the fans appear to forget or conveniently ignore too often). 

DC is often considered sufficiently evolutionary for its design to be considered by many to put them in position for a partial award for "developmental" purposes.  The "boring" design that gets the least media attention may well be the one that most aligns with the mission that has been defined by NASA.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/31/2014 04:02 pm
(If this is still a party thread)

What's wrong with the view counts for the images in Helodriver's  3rd image dump (http://forum.nasaspaceflight.com/index.php?topic=34841.msg1207324#msg1207324)? :P
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 05/31/2014 04:06 pm
Granted. I like your use of unsubstantiated now... I think I'm finally coming round to your way of thinking!
You maybe could be a bit more verbose and explain yourself to us noobs though!

Channeling Blaise " I would have written a shorter letter, but I did not have the time." Pascal.
Jim might find he actually saved himself some time if his responses contained more data.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/31/2014 04:16 pm
Jim might find he actually saved himself some time if his responses contained more data.

You have to learn to read between the bytes.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 05/31/2014 04:18 pm
I'll say this much: SpaceX are taking an enormous risk with this strategy. Dragon-2 is different enough from Dragon-1 to be considered untested and this could give NASA grounds to deny it the Commercial Crew missions. If they're hoping that issues with RD-180 and, consequently, Atlas-V will tilt the field in their favour, that is a big and extremely risky assumption on which to base their strategy.

Personally, I would have developed a Dragon-1 crew variant and used the income from that to fund development of Dragon-2. Something broadly similar to the cargo Dragon would mean a lot of pre-tested systems, structures and procedures and greatly increased customer confidence in the type (not just NASA either). Dragon-2 is a shot-in-the-dark and is going to be a hard sell.

SpaceX just seems to be rushing ahead and causing themselves difficulties because of it. There have been delays due to the core landing gear (not big ones yet, thankfully). Having to prove what must be a mostly-new vehicle to get crew missions will be another cause of major delays.

Maybe I'm too cautious but this strikes me as taking a bit too much of a risk for the sake of taking a risk. Elon strikes me as more and more a real-world Moist von Lipwig (http://en.wikipedia.org/wiki/Moist_von_Lipwig), a wild, daredevil personality who is never happier than when taking enormous technical and personal risks out of a combination of adrenaline addiction and a desire to prove himself able to outsmart the entire world.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/31/2014 04:25 pm
Jim might find he actually saved himself some time if his responses contained more data.

You have to learn to read between the bytes.

Huh? No need, just read the bytes. All the silly detour via ad hominem and strawmen claims lead to Jim stating his original argument in generalized form. Lo and behold now it got accepted. The debate in between belongs to xkcd strip. Maybe he needs to copypaste his responses twice for people who like to read more words.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ncb1397 on 05/31/2014 04:31 pm
There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected.

Can you cite the last space-related riot? I cannot remember any.

Cassini launch?

Quote
CAPE CANAVERAL, Florida (CNN) -- A Saturday protest against NASA's upcoming launch of a plutonium-powered spacecraft ended with the arrests of several dozen people.

Hundreds gathered outside the fence surrounding the pad where the Cassini probe is scheduled to be launched October 13 for a seven-year trip to Saturn. At the end of the rally, five members of the group Grandmothers for Peace walked through the main gates of the facility and were arrested by Air Force guards.

Other protesters threw pieces of carpet over the barbed-wire fence, and about 20 people were arrested when they attempted to climb over.

http://www.cnn.com/TECH/9710/04/cassini/
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Paul_G on 05/31/2014 04:32 pm
Did anyone who attended the unveil and sat inside the capsule take a look up inside, to see how the docking hatch fits into the overall design?

Paul

Just seen Helodriver's first batch of photos in the unveil topic, there is one looking up at the hatch.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 05/31/2014 04:33 pm
Since I brought up the possibility of a corner failure mode (two SD) and unless a demonstrated recovery mode for a safe PD landing during testing, it might be possible that NASA will not request this type of landing for its crew as an option...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 05/31/2014 04:33 pm
Also, i dont think the most amazing bit of technology that they unveiled here has been noticed in this thread at all.

Watch the three seconds of video very closely : OMG how did they do that !?

  http://bit.ly/1kbXe6X
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: su27k on 05/31/2014 04:34 pm
But NASA has set the objective of selecting something for ISS they essentially they see as proven, reliable and simple;

If that's all the criteria they'll use, their best bet is Soyuz.

Quote
this craft, In striving to be "revolutionary," proves that they seem to prioritize flash and salesmanship, which may actually hurt their prospects, in the opinion of some. 

In the opinion of whom? I have yet to see anyone in the media (general or space specific) express this opinion.

Quote
There are several technologies here that remain to be flight tested and could well prove problematic,

What else besides the heat shield issue?

Quote
some of which have historically been considered and discouraged, such as hatches in the heat shield.

You do realize they don't have to put legs on this thing to make it work?

Quote
Lots of flight test work to be done here. Lots of potential for problems to arise in the timeframe available.  So much for being "ahead."

And they have a schedule for doing these tests, where is the schedule for the other contenders if you think they're ahead?

Quote
The amazing peoples say Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction. 

There is no contradiction, V2 may be x% different from V1, while the other (100-x)% can still be flight tested hardware, the point is x is pretty high and 100-x is not zero.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 05/31/2014 04:39 pm
Garret said that V2's parachute system has been tested.

Helicopter drop. It was publicised, complete with pics / video. Definitely not secret.

cheers, Martin
Looks like a v1 drop test (yes I already know you're going to say its v2).
http://m.space.com/24337-spacex-wet-drop-tests-human-rated-crew-capsule-at-sea-video.html


It is the V2 parachute system. Also note the nose cone that is attached - something that threw us for a loop at the time. I made this parachute system comparison at the time, highlighting the difference between the V1 and V2 parachute systems:
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ronsmytheiii on 05/31/2014 04:44 pm
NASA has set the objective of selecting something for ISS they essentially they see as proven, reliable and simple; this craft, In striving to be "revolutionary," proves that they seem to prioritize flash and salesmanship, which may actually hurt their prospects, in the opinion of some.

The technologies for Dragon's propulsive landing are not "revolutionary" The Superdraco's are primarily intended for launch aborts, SpaceX only added the ability to throttle.  The primary abort landing mode, landing by parachute in the Atlantic, is still conservative, proven, and reliable (ie Dragon 1 does it)  Much like Falcon 9 V 1.1, Dragon 2 still has a conservative design that can be used in a conventional method or the new method once it is proven.

Quote
There are several technologies here that remain to be flight tested and could well prove problematic, some of which have historically been considered and discouraged, such as hatches in the heat shield.  Lots of flight test work to be done here. Lots of potential for problems to arise in the timeframe available.  So much for being "ahead."

Hatches on heat shields have flown before, see the below image.  Also, SpaceX can test designs in an arc jet facility, no need for "many" flight tests. 

Quote
DC is often considered sufficiently evolutionary for its design to be considered by many to put them in position for a partial award for "developmental" purposes.  The "boring" design that gets the least media attention may well be the one that most aligns with the mission that has been defined by NASA.

I hope DC is picked as a backup, but that is not assured at all.  In the end, it is about the business case (Boeing has struggled on this end) and technical merit. Boeing might be ahead in the latter, but that is not because of the "revolutionary" features in Dragon 2.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 05/31/2014 04:50 pm
Also, i dont think the most amazing bit of technology that they unveiled here has been noticed in this thread at all.

Watch the three seconds of video very closely : OMG how did they do that !?

  http://bit.ly/1kbXe6X
OMG! Senator Shelby was right when he was speaking of SpaceX magic!
-this is a party thread after all.
Very good catch savuporo!
We'll need some Kremlinology on this too!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/31/2014 04:52 pm
I have no explanation for the white mist around the vehicle. It must be witchcraft.

edit: and reeling curtains sorcery!

DragonV2 must be dipped into lake until these abominations are gone.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJA on 05/31/2014 04:54 pm
Also, i dont think the most amazing bit of technology that they unveiled here has been noticed in this thread at all.

Watch the three seconds of video very closely : OMG how did they do that !?

  http://bit.ly/1kbXe6X (http://bit.ly/1kbXe6X)
OMG! Senator Shelby was right when he was speaking of SpaceX magic!
-this is a party thread after all.
Very good catch savuporo!
We'll need some Kremlinology on this too!

Here (http://forum.nasaspaceflight.com/index.php?topic=34841.msg1207500#msg1207500)

I think you should tweet Molly and ask. :P

EDIT: Helodriver, if you're reading this - did you check out those curtain-vacuums?
At 3:19 in the YouTube video, you can see a string.. attached to the curtain somewhere along the middle/even the top. Let it drop, then reel it in mega-fast.

Cassini launch?

Property damage: None.
Casualties: None
So.. protest maybe, but not a riot.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Blackstar on 05/31/2014 05:01 pm
Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction. 

And that's a really good point.

Imagine what would happen if NASA rejected the design because of the retrorocket approach? That would be a conservative engineering decision, but I suspect that it might result in a lot of kvetching here...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Blackstar on 05/31/2014 05:03 pm
There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected.

Can you cite the last space-related riot? I cannot remember any.

Cassini launch?



Ah, good one!

But that was an anti-space-related (near) riot.

Can anybody cite a pro-space-related riot?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/31/2014 05:05 pm
Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction. 

And that's a really good point.

Imagine what would happen if NASA rejected the design because of the retrorocket approach? That would be a conservative engineering decision, but I suspect that it might result in a lot of kvetching here...

Dragon 2 can land with chutes, and will, long before NASA would allow propulsive landings with their cargo/people.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alkan on 05/31/2014 05:08 pm
Agree. The idea that this presentation indicates they "must" be chosen for commercial crew is absurd.  We saw a flashy craft and one that will no doubt fly...somewhere. But NASA has set the objective of selecting something for ISS they essentially they see as proven, reliable and simple; this craft, In striving to be "revolutionary," proves that they seem to prioritize flash and salesmanship, which may actually hurt their prospects, in the opinion of some. 

There are several technologies here that remain to be flight tested and could well prove problematic, some of which have historically been considered and discouraged, such as hatches in the heat shield.  Lots of flight test work to be done here. Lots of potential for problems to arise in the timeframe available.  So much for being "ahead." 

The amazing peoples say Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction.  While the original ARES mantra of " safe, simple, soon" carries a lot of negative connotations, the fact is, that slogan sums up nicely what NASA was and is seeking in finding an orbital taxi candidate -- a role that candidly is not particularly flashy or complex.  This presentation shows Musk can innovate, but was that what NASA requested?  ( and paid for through the commercial crew process -- something the fans appear to forget or conveniently ignore too often). 

DC is often considered sufficiently evolutionary for its design to be considered by many to put them in position for a partial award for "developmental" purposes.  The "boring" design that gets the least media attention may well be the one that most aligns with the mission that has been defined by NASA.

I think they should change their slogan from "safe, simple, soon" to "safe, reliable, soon." Simplicity implies that they desire reliability, but reliability does not necessarily entail simplicity.

Who care's if SpaceX advertises themselves in the presentation. They're a company, that's what companies do: advertise. What should they do, cast doubt on their own craft? Of course they're going to be optimistic about themselves, and create a public image of optimism, because that helps ensure that they keep seeing money.

While I wouldn't be willing to take a ride in this craft until it was proven safe with a long track record, I see no reason to think that the most likely outcome will be that it shows itself to be a safe, reliable craft, that will be ready soon given the speed at which SpaceX develops their crafts.

And seriously, this company has the world's cheapest rockets of its size, and they're a company that started in 2002. Their whole approach has worked very well so far, so I don't see the need to cast doubts. Healthy skepticism goes as far as "they haven't proven it yet, I'll believe it when it passes all tests."

And that's my position: they haven't proven it yet, but they probably will given their incredible track record. I don't see any reasonable point of debate here, actually. Either it works or it doesn't. Arguing about it won't change whatever the outcome is.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Giovanni DS on 05/31/2014 05:10 pm
About hatches on heat shields, shouldn't the fuel lines and the landing gear openings in STS (and DC) be classified as such? if so, there is a lot of flight history.

Giovanni
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Will on 05/31/2014 05:10 pm
Agree. The idea that this presentation indicates they "must" be chosen for commercial crew is absurd.  We saw a flashy craft and one that will no doubt fly...somewhere. But NASA has set the objective of selecting something for ISS they essentially they see as proven, reliable and simple; this craft, In striving to be "revolutionary," proves that they seem to prioritize flash and salesmanship, which may actually hurt their prospects, in the opinion of some. 

There are several technologies here that remain to be flight tested and could well prove problematic, some of which have historically been considered and discouraged, such as hatches in the heat shield. 

Every Space Shuttle that went to space had hatches in the heat shield.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Barrie on 05/31/2014 05:24 pm
Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction. 

And that's a really good point.

Imagine what would happen if NASA rejected the design because of the retrorocket approach? That would be a conservative engineering decision, but I suspect that it might result in a lot of kvetching here...

Dragon 2 can land with chutes, and will, long before NASA would allow propulsive landings with their cargo/people.

and I'd like to think Dragonfly can do a lot to build confidence at reasonable cost.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 05/31/2014 05:34 pm
The landing are not the design risk IMO, but if anything is going to trip up Dragon 2 , it is the LAS. Even EM has said this is what slows them down.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Dave G on 05/31/2014 05:40 pm
Also, i dont think the most amazing bit of technology that they unveiled here has been noticed in this thread at all.

Watch the three seconds of video very closely : OMG how did they do that !?

  http://bit.ly/1kbXe6X
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Barrie on 05/31/2014 06:05 pm
There is actually little doubt they're going to be not selected. The general public would riot if they weren't selected.

Can you cite the last space-related riot? I cannot remember any.

Cassini launch?



Ah, good one!

But that was an anti-space-related (near) riot.

Can anybody cite a pro-space-related riot?

No, but public opinion seemed to play a part in Poland becoming a member of ESA, against the judgment of the Minster of Finance.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/31/2014 06:08 pm
SpaceX has time to prove out Dragon v2. And remember, NASA has optics on what they are doing.

NASA in April bought Soyuz seats through end of 2017 and Soyuz life-boat and return functions through 2018.

-Dragon V2 will run 30  Propulsive landing tests beginning towards the end of 2014 and throughout 2015
-Dragon V2 will have 2 Abort tests. Pad Abort in 2014, In-flight abort in 2015
-Dragon V2 will have both un-crewed and crewed orbital test flights in 2015 - 2016
-They have control over Pad39A, one of only 2 human launch sites in the country
-They continues to develop critical mission experience with the ISS
-I believe NASA is extremely supportive of pinpoint accurate propulsive landing
-I believe SpaceX is offering the least expensive per-seat price
-F9V1.1 is a competitively inexpensive launcher to produce and operate
-Etc..

In my educated "opinion", SpaceX will be selected. Frankly, I believe Dragon V2 has already been selected in the minds of those who matter, although nobody would admit that yet. 

(I personally hope to hell DC makes it as well though)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 05/31/2014 06:23 pm
Garret said that V2's parachute system has been tested.

Helicopter drop. It was publicised, complete with pics / video. Definitely not secret.

cheers, Martin
Looks like a v1 drop test (yes I already know you're going to say its v2).
http://m.space.com/24337-spacex-wet-drop-tests-human-rated-crew-capsule-at-sea-video.html


It is the V2 parachute system. Also note the nose cone that is attached - something that threw us for a loop at the time. I made this parachute system comparison at the time, highlighting the difference between the V1 and V2 parachute systems:

Nice, thanks.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alkan on 05/31/2014 06:45 pm
Agree. The idea that this presentation indicates they "must" be chosen for commercial crew is absurd.  We saw a flashy craft and one that will no doubt fly...somewhere. But NASA has set the objective of selecting something for ISS they essentially they see as proven, reliable and simple; this craft, In striving to be "revolutionary," proves that they seem to prioritize flash and salesmanship, which may actually hurt their prospects, in the opinion of some. 

There are several technologies here that remain to be flight tested and could well prove problematic, some of which have historically been considered and discouraged, such as hatches in the heat shield. 

Every Space Shuttle that went to space had hatches in the heat shield.

(http://exploration.grc.nasa.gov/education/rocket/gallery/shuttle/Landing.jpg)

Oh no! We have to go back in time to get rid of the landing gear and scrap the Space Shuttle because it had hatches in the heat shield!

I think it's funny how people point out problems that aren't problems to act like they know what they're talking about.

FFS, I know when I don't know what I'm talking about, generally. That's why I can't see any problems with the new spacecraft. Sure, maybe there are problems, but how the hell would I know when something is a problem?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 05/31/2014 07:23 pm
SpaceX has time to prove out Dragon v2. And remember, NASA has optics on what they are doing.

NASA in April bought Soyuz seats through end of 2017 and Soyuz life-boat and return functions through 2018.

-Dragon V2 will run 30  Propulsive landing tests beginning towards the end of 2014 and throughout 2015
-Dragon V2 will have 2 Abort tests. Pad Abort in 2014, In-flight abort in 2015
-Dragon V2 will have both un-crewed and crewed orbital test flights in 2015 - 2016
-They have control over Pad39A, one of only 2 human launch sites in the country
-They continues to develop critical mission experience with the ISS
-I believe NASA is extremely supportive of pinpoint accurate propulsive landing
-I believe SpaceX is offering the least expensive per-seat price
-F9V1.1 is a competitively inexpensive launcher to produce and operate
-Etc..

In my educated "opinion", SpaceX will be selected. Frankly, I believe Dragon V2 has already been selected in the minds of those who matter, although nobody would admit that yet. 

(I personally hope to hell DC makes it as well though)

Many believes you have... ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 07:36 pm
The inherent weaknesses of the shuttle systems are exactly why we are havin this debate at all.  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.if there is a newfound emphasis on safety and simplicity/ reliability,specifically in the wake of a catastrophic burnthrough, this should not be a surprise. It is added risk.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: john smith 19 on 05/31/2014 07:41 pm
SpaceX has time to prove out Dragon v2. And remember, NASA has optics on what they are doing.

NASA in April bought Soyuz seats through end of 2017 and Soyuz life-boat and return functions through 2018.

-Dragon V2 will run 30  Propulsive landing tests beginning towards the end of 2014 and throughout 2015
-Dragon V2 will have 2 Abort tests. Pad Abort in 2014, In-flight abort in 2015
-Dragon V2 will have both un-crewed and crewed orbital test flights in 2015 - 2016
-They have control over Pad39A, one of only 2 human launch sites in the country
-They continues to develop critical mission experience with the ISS
-I believe NASA is extremely supportive of pinpoint accurate propulsive landing
-I believe SpaceX is offering the least expensive per-seat price
-F9V1.1 is a competitively inexpensive launcher to produce and operate
-Etc..

In my educated "opinion", SpaceX will be selected. Frankly, I believe Dragon V2 has already been selected in the minds of those who matter, although nobody would admit that yet. 

(I personally hope to hell DC makes it as well though)
I think the truth is that no once can say who will win down select.

My hope is that all 3 designs can be certified so that any of them could go to outside funders and say "NASA confirms we are safe enough that we could dock to the ISS without them worrying," which would be a very good thing to have, if for example other destinations were to appear.

Whatever you think of Spacex's technical design it's clear they are the only one racking up live operational experience of anything like a similar vehicle with the ISS. That IMHO should figure in any weighting criteria NASA will use in judging for a down select. In Powerpoint everything runs like clockwork, but they know that IRL things happen. How to cope with them (and how to fine tune the system so you don't get flummoxed next time) you only really learn by doing.

Boeing's ISS experience is Shuttle based and IIRC would be what was left over from the staff they retained from USA. I'm talking actual "sharp end" experience of people directly planning and operating trips to space.

SNC have none. OTOH they would give design diversity both in design (LB Vs capsule), Materials (composite Vs Aluminum) and propulsion (hybrid Vs hypergols).

The CTS100 looks like the "safe pair of hands" option, but look a little closer...

Boeing's capsule experience is what 4 decades old?  IIRC it's business plan was basically "CCiCAP for NASA," with no plans to look for outside business. NASA did not rate that approach highly.  I personally did not like the way they appeared to be leasing space at the Cape while saying in effect "If we don't win CCiCAP they'll be no jobs." I don't like petulant threatening behavior, especially from multi billion dollar corporations, although perhaps they just had bad PR and that's the way it came out.  :(

Incidentally I don't think we've heard anything about what Boeing's using for a TPS. Are they in line for the next batch of re-constituted Avcoat after MPCV? Or have the mad fools decided to throw caution to the wind and use an ablator that wasn't developed 60 years ago (but did protect the fastest man made object ever to reenter Earth's atmosphere) ?

As they say of pool "The game's not over till the last balls down." Spacex may not win the down select, but I think they have a very strong hand and I'd be equally surprised if they didn't.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Herb Schaltegger on 05/31/2014 07:57 pm
Boeing's ISS experience is Shuttle based and IIRC would be what was left over from the staff they retained from USA. I'm  talking actual "sharp end" experience of people directly planning and operating trips to space.

That is completely incorrect. Boeing itself designed, built and provides operational support engineering for all U.S. pressurized elements of the ISS, and they provided design integration, technical oversight and requirements compliance control over the European and Japanese modules as well. For that matter, all the exterior truss systems were integrated and overseen by McDonnell Douglas, which is of course now Boeing as well.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Giovanni DS on 05/31/2014 08:02 pm
Propulsive landing is difficult, never mind he hatches issue. It involves serious tradeoffs of weight and fuel.

The Dragon v2 has parachutes too, isn't that nice? a backup system should be great safety I think.

The hatch has not yet become an issue, is there any evidence of that?

Tradeoffs of weight and fuel are not important for safety, only for performance, anyway, they use the same fuel and engines dedicated to the escape system if I understood it right. I imagine they must have evaluated their tradeoffs years ago.

Not an expert anyway, please forgive any obvious error.

Giovanni
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: WindyCity on 05/31/2014 08:04 pm
I have been an unabashed fan of human spaceflight from the time I watched the first Mercury flights on television when I was a boy, and I am currently a huge fan of Elon Musk and SpaceX. What I am not is an industry insider or an aerospace engineer. The derogatory term “amazing people,” I gather, is used to refer to an individual who rattles off enthusiastically, or overly optimistically, about technical issues regarding which he (or she) has erroneous or insufficient knowledge.  Why such forum behavior would frustrate or inflame those who do have the requisite education or experience to render informed opinion on rockets, spacecraft, or human spaceflight is not difficult to comprehend. That said, a party thread is not L2 where Chris Bergin and the other managers maintain high technical standards for posts. Therefore, a spirit of patience and indulgence on the part of the pros toward the occasionally ignorant or misinformed post on the open side, submitted innocently by space-loving laity, would be, I think, kind. After all, what the country desperately needs is a galaxy of such fans who will pressure their representatives to support NASA and other space-ward enterprises. Am I right, or am I right? Phew! End of rant.

Now I would like to offer a—I assure you, non-technical—thought on the subject of the readiness of the Dragon V2 for flight and the possibility that SpaceX won’t be chosen to be NASA’s space taxi.

It seems overwhelmingly reasonable to me that many unresolved technical issues remain to be dealt with before SpaceX will be ready to fly its new capsule. It wouldn’t surprise in the least if significant changes to its design cropped up over the next two years involving the hatch, the oval windows, the landing legs, the instrument panel, the couches, and the dock cover, just to name a few. It would be a gross mistake, in my opinion, to look at the craft that went on display the day before yesterday as a finished product. Informed individuals in this forum have raised a number of serious concerns about a variety of its features. Given SpaceX’s success so far in building flight-worthy vehicles, however, what reason is there to conclude that the company won’t succeed again? Musk has said that even if the Dragon V2 failed to be chosen by NASA to ferry astronauts to the ISS, his company would “soldier on” in its development. I took him to mean that he would rely on internal funding to pay for its continued R&D and bring it, eventually, to a launch pad. Assuming that to be true,  it would shock and greatly disappoint me if the craft never reached orbit.

Now a bit of speculation:  Suppose NASA passed SpaceX over and chose either of or both Boeing’s or SNC’s entries instead, and SpaceX, undeterred, moved forward with Dragon V2. If Musk’s concept were to succeed, might not it be at least as safe, and cheaper to build and launch, than either of its competitors? If it turned out that the Dragon V2 worked spiffily, and cost an armload less than the DC or the CST-100, would it be unreasonable if down the road NASA were to switch to it? Musk might be stubborn enough to gamble on such an outcome. Also, let's not forget Bigelow. Space tourists or researchers could be flying happily on a Dragon to an inflatable space station that made the ISS look like this: (http://ih1.redbubble.net/work.6186668.1.flat,800x800,070,f.jpg). This is a party thread, right?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/31/2014 08:12 pm
Elon strikes me as more and more a ...wild, daredevil personality who is never happier than when taking enormous technical and personal risks out of a combination of adrenaline addiction and a desire to prove himself able to outsmart the entire world.

>>he may outsmart himself. LET HIM BUILD AND FLY HIS TOY. But NASA is looking to hire a taxi to LEO.

I think this is a misunderstanding of SpaceX's entire raison d'être: make the lowest-cost "safe space taxi" possible.  You guys think he's just a wild daredevil, when in fact he's a steely-eyed cost-cutter. ;)  This is something American manufacturing has not historically been good at.  My experience is in electronics manufacturing, and I can tell you that my Chinese co-workers are continually refining processes and finding new suppliers to squeeze out every last penny and they are very good at it.  Apple has also proven to be extremely good at this, in part through strategic investment in manufacturing capabilities. As a result Apple can make healthy profits selling a $700 device while its competitors find themselves (a) pressured to undercut Apple on price, and (b) barely making a profit at $700.   *Anyway...*

SpaceX is making design decisions now that affect its per-flight costs into the indefinite future.  If they can retire the technical risk (and their track record to date is pretty good) they will have the lowest-cost way to get people to space.  After a while, capitalism does the rest.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 05/31/2014 08:13 pm
Soyuz does on-land landings via parachute --- but they often land hundreds of miles off course

Being that much off course is not due parachutes, the error has happened in re-entry guidance. If Dragon begins descent that much off-course SuperDracos aren't going to propel it back to original target.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/31/2014 08:19 pm
Soyuz does on-land landings via parachute --- but they often land hundreds of miles off course

Being that much off course is not due parachutes, the error has happened in re-entry guidance. If Dragon begins descent that much off-course SuperDracos aren't going to propel it back to original target.

My point is just that parachutes do not allow "pinpoint guidance" -- which is especially important in abort situations (as in the linked Soyuz example).  SuperDracos aren't enough to bring the capsule back to the landing point in all situations, but they certainly offer enough control  (a) ensure that you land in the correct country (Soyuz 18-a almost landed on the wrong side of the Russia/China border w/ military secrets on board), and (b) ensure that you can choose an appropriate landing site to prevent you from rolling off a cliff after touchdown!  For wings fans, this is usually called something like "crossrange capability on abort".

(I'm actually very curious about what the UI for an abort would look like.  Visibility 'down' isn't great.  One would hope that the on-board pilot could select from a largish number of pre-programmed landing spots, and perhaps do some manual guidance with a moving map display in the worst case.)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 08:21 pm
Has the case been made in regards to the real benefit involved in propulsive landing beyond convenience?  Nasa may well regard it more valuable to expend extra propellant on ISS reboost rather than "pinpoint" landing given than landing on chutes seems to accomplish what they need reasonably well. Carrying chutes and propellant works but is it the best answer for the mission requirements?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/31/2014 08:24 pm
Has the case been made in regards to the real benefit involved in propulsive landing beyond convenience?  Nasa may well regard it more valuable to expend extra propellant on ISS reboost rather than "pinpoint" landing given than landing on chutes seems to accomplish what they need reasonably well. Carrying chutes and propellant works but is it the best answer for the mission requirements?

Again: the real benefit is cost.  Elon wants to turn that capsule around the same day, and doesn't want to have to wait/pay for someone to fish it out of the ocean, refurb it, or even truck it across the country.  If pinpoint landings (and thus fast turnaround) enable Elon to offer "single digit millions" costs per-passenger -- isn't that benefit enough?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 05/31/2014 08:25 pm
Cassini launch?

Property damage: None.
Casualties: None
So.. protest maybe, but not a riot.

I was at the SEDS pro-Cassini rally in front of the White House back in September '97. Drove out from Michigan to attend - it was fun! Someone saw my Apple-LaserWriter-printed sign and thought it was professionally produced, and so accused us of being on the payroll of some shadowy puppetmaster.  ;D That whole situation is why to this day I revile and loathe Michio Kaku - *spit*  >:( I still take a bit of personal pride at the magnificence of Cassini's datastream.  :D

I'll have to see if I can dig up my photos.

http://archive.seds.org/spaceviews/cassini/9710-01.html
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Giovanni DS on 05/31/2014 08:26 pm
Has the case been made in regards to the real benefit involved in propulsive landing beyond convenience?  Nasa may well regard it more valuable to expend extra propellant on ISS reboost rather than "pinpoint" landing given than landing on chutes seems to accomplish what they need reasonably well. Carrying chutes and propellant works but is it the best answer for the mission requirements?

Is station boost part of the requirements for the LEO taxi?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 05/31/2014 08:31 pm
More amazing people excuse making and dismissing of risk. This is how NASA GOT ASTRONAUTS KILLED. [...] Parachutes are lighter and simpler.

I think you are forgetting that water-based parachute landings are also rather dangerous: https://en.wikipedia.org/wiki/Splashdown#Disadvantages

Soyuz does on-land landings via parachute --- but they often land hundreds of miles off course and have their own set of dangers: one almost rolled off a cliff! https://en.wikipedia.org/wiki/Soyuz_7K-T_No.39#Mission_highlights

There's always a trade-off.

CST-100 will land on land with airbags.

That Soyuz mission, well that's actually an interesting example. First of all, assuming a launch from the Cape, Dragon will come down on water in the case of an abort, in all likelihood. Second, that Soyuz actually came down on a snow-covered slope! How do you intend to make a proper landing on legs if there is no flat, open, clean terrain in close proximity? In such a case I'd rather land with parachute and airbags.

Musk wants to land on Mars at some point, I think that was his main motivation for choosing retropropulsion (and maybe he sees a big market for tourism).

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/31/2014 08:32 pm
[quote author=Ben the Space Brit
I'll say this much: SpaceX are taking an enormous risk with this strategy. Dragon-2 is different enough from Dragon-1 to be considered untested and this could give NASA grounds to deny it the Commercial Crew missions.

>>i tried to make this point and the knives came out. Don't let facts get in the way, i guess.



V-2 is a shot-in-the-dark and is going to be a hard sell.

>>yes, the amazing peoples are forgetting that the buyer is NASA. Not the attendees at the next Star Trek convention. The fact is, its a very different animal than v-1. Space x has proven they are great with launchers. A crew vehicle is a success by getting its crew where they need to go and back safely. Space X so far, has zero experience on that, and putting a new vehicle into the field is more of a reset than some folks here apparently are able to admit to themselves.  Frankly, DC, because of its HL-20 heritage seems to be a more known product than the " tesla in the sky" approach.


SpaceX just seems to be rushing ahead and causing themselves difficulties because of it...Maybe I'm too cautious but this strikes me as taking a bit too much of a risk for the sake of taking a risk.

>>nasa us looking to reduce risk. And frankly, musk does himself no favors by the nasa bashing.  They are paying for the bulk of his venture.

 Elon strikes me as more and more a ...wild, daredevil personality who is never happier than when taking enormous technical and personal risks out of a combination of adrenaline addiction and a desire to prove himself able to outsmart the entire world.

>>he may outsmart himself. LET HIM BUILD AND FLY HIS TOY. But NASA is looking to hire a taxi to LEO.  This presentation only further convinces me that the way forward is for a full award to Boeing for crew vehicle but exploring their idea or letting Space X do what it has proven it does well -- providing launch service for that vehicle, and continue driving costs down, while a developmental award goes to DC  to get us a winged option further down the road.

I just want to make sure I understand your rationalization?

amazing people self delusions + Start Trek conventioneers + risk for risk sake-wild-daredevil-adrenaline addicted personality complex + NASA bashing + building and flying toys = Boeing is the only viable option forward.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/31/2014 08:37 pm
Musk wants to land on Mars at some point, I think that was his main motivation for choosing retropropulsion (and maybe he sees a big market for tourism).

No, he has explicitly stated that the reason for retropropulsion, both for the first stage and for Dragon, is to allow same-day turnaround by flying back to the launch point.

I'm sure he'd agree that the ability to land on Mars is a nice added benefit, but I have heard him state this as an explicitly economic case.  (Maybe someone can help me by finding the quote on QuantumG's site?)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: arachnitect on 05/31/2014 08:37 pm
IIRC it's business plan was basically "CCiCAP for NASA," with no plans to look for outside business. NASA did not rate that approach highly.

I think the whole "outside business" thing is a charade, but if we're going to talk about it, I'll note that BA is partnered with Bigelow.

Incidentally I don't think we've heard anything about what Boeing's using for a TPS. Are they in line for the next batch of re-constituted Avcoat after MPCV? Or have the mad fools decided to throw caution to the wind and use an ablator that wasn't developed 60 years ago (but did protect the fastest man made object ever to reenter Earth's atmosphere) ?

Latest info is Avcoat.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 05/31/2014 08:39 pm
Musk wants to land on Mars at some point, I think that was his main motivation for choosing retropropulsion (and maybe he sees a big market for tourism).

No, he has explicitly stated that the reason for retropropulsion, both for the first stage and for Dragon, is to allow same-day turnaround by flying back to the launch point.

I'm sure he'd agree that the ability to land on Mars is a nice added benefit, but I have heard him state this as an explicitly economic case.  (Maybe someone can help me by finding the quote on QuantumG's site?)

Well you don't need such fast turnaround except you see a truly big market for orbital spaceflight (i.e. tourism). Retropropulsion for the first stage is needed because its too big/fragile for airbags.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 05/31/2014 08:44 pm
Propulsive landing is also a testbed for propulsive Mars EDL. The same reason NASA wanted to fly their P3 to observe the F9 CRS-3 stage reentry. ISTM these converging imterests at least partially negates the notion NASA frowns on Dragon V2 using it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 08:54 pm
>>It is clearly a benefit, and an exciting one...but is it the benefit NASA seeks for  mission requirement now?  Will emphasizing this development increase schedule risk since the overriding goal is to get a domestic LEO taxi in place  in time for expiration of their commitment to Soyuz in 2018.    And a lesser question: does there then need to be another solution found for station reboost as a result, incurring more cost and technical expense and schedule risk? Cost is important long term. It is not the critical factor in reaching the current time-constrained goal of providing an alternative to Soyuz as taxi.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 09:03 pm
It is not currently a requirement, however Boeing originally stated that its pusher LAS would expend its propellant load on reboost if unused for abort. Currently done by station thrusters, which are resupplied by Progress regularly. Reboost option  Lessens dependence further on Russians. Not sure if this is still in the plan.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ThereIWas3 on 05/31/2014 09:04 pm
...but is it the benefit NASA seeks for  mission requirement now?

I think Elon views NASA as a short term customer.  He is looking further ahead than they are.  And rather than wait
for congressional concensus before doing reasearch and development on going to Mars, he is doing it now, while
also meeting NASA's short term requirements.

I don't think NASA has any requirements that a CCDev supplier not do something.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sanman on 05/31/2014 09:10 pm
Just from the music alone, I feel like I'm listening to a car commercial:

https://www.youtube.com/watch?v=69QoybIdZ_o
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 09:16 pm
>>Roughly speaking, my point is that Space X enthusiasm (bordering on blind fanaticism for some) is no excuse for ignoring that v-2 is far from the "leading" or "obvious winner" among the entrants BECAUSE IT SEEMS TO BE AIMING AT A DIFFERENT GOAL.  V-2 represents quite a departure from the Ccdev selection process's original intent. It's an exciting vehicle for sure. But it has a ways to go in developmental cycle with lots of question marks, and it does not reflect what NASA Has stated as its goal: a quick-build, reliable , proven technologies-based taxi service to ISS by 2018.  Candidly, DC is a stretch as well, but it has enough shuttle heritage and NASA likes the winged option as an alternative to capsule.  I agree with many that Boeing is the safe choice to ensure we have an ISS taxi by 2018, but i hope Space x and Sierra Nevada can find markets and missions for their fine vehicles as well.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 09:24 pm
Musk may see NASA AS "a short term customer" but likewise, NASA may view musk as a short term contender for their contract if he heads down a path that jeopardizes their time constrained goal of fielding a taxi when soyuz commitment runs out and before ISS is splashed. He can develop a more advanced craft once the taxi requirement is safely met.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 05/31/2014 09:27 pm
Well see that is the thing EM does not share the goals and responsibilities for defending the nation (AF) or science (NASA) he wants to make humanity a multi- planet species. And his acolytes will tell you that capitalism drives the whole thing, like as if capitalism doesn't drive Boeing. That's the really funny part.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Alkan on 05/31/2014 09:32 pm
The amount of people talking out of their ass on this thread is kind of getting annoying.

Saying that hatches in the heat shield is some type of new risk is just wrong. It might be a risk, but look at the shuttle. It NEVER failed from the wheel well seams in the heat shield. It failed from a piece debris knocking off a tile that cause disintegration of the craft. It never failed at the wheel well.

This isn't even as different as the space shuttle was. This new capsule is coming off of improvements to existing technology. It's completely incremental, even though the overall effect achieved is supposed to be revolutionary. The shuttle flew 135 times, out of which two failed. And those two failures were both from issues that happened during launch. Even though one broke up during reentry, it was due to a piece of foam striking the heat shield on launch.

I think people some people like to be contrarian for the sake of being contrarian. If you're going to be a cynic, you might want to back up your cynicism with facts, knowledge and expertise, instead of pointing at something that you know nothing about, and proceed to pretend to know the level of risk associated with it.

I don't know how risky the new craft is. I can see that it's still a capsule and is likewise less of a jump than the Space Shuttle, but has more of an emphasis on safety than the Space Shuttle ever had. SpaceX itself is in danger if their new craft doesn't work, so they've gotta be extra careful about it.

Beyond that I can't say much on the safety of the craft. No one really can yet because the thing is untested. But I think it's reasonably likely to work and to be very safe with lots of refinement and testing.

So, I don't see what all the cynicism is about. It's like there's a straw-man that all the people (including myself) excited about the new capsule think that it's just going to be ready to go without extensive, rigorous testing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 05/31/2014 09:33 pm
Musk may see NASA AS "a short term customer" but likewise, NASA may view musk as a short term contender for their contract if he heads down a path that jeopardizes their time constrained goal of fielding a taxi when soyuz commitment runs out and before ISS is splashed. He can develop a more advanced craft once the taxi requirement is safely met.

I don't think Elon or Nasa needs to hear what we think about this.  Elon has his timeline; if he is first to flight it really doesn't matter how much risk he did/did not buy down along the way.   It's not worth arguing about; let's just wait and see.

Well see that is the thing EM does not share the goals and responsibilities for defending the nation (AF) or science (NASA) he wants to make humanity a multi- planet species. And his accolytes will tell you that capitalism drives the whole thing, like as if capitalism doesn't drive Boeing. That's the really funny part.

It's not "capitalism" -- it's reducing *cost per person*.  SpaceX is not a publicly-traded company, there's no requirement that it makes any money at all (except enough to allow Elon to continue funding his R&D aims).   Elon has his own reasons for reducing cost, he's *not* doing it in order to improve his position in the marketplace or enhance his chances of winning the NASA contract, per se.

*Cost* is the driver, not *profit*.   Hence, not "capitalism", strictly speaking.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 05/31/2014 09:41 pm
Well see that is the thing EM does not share the goals and responsibilities for defending the nation (AF) or science (NASA) he wants to make humanity a multi- planet species. And his accolytes will tell you that capitalism drives the whole thing, like as if capitalism doesn't drive Boeing. That's the really funny part.

I would hardly call government bedfellows legitimate capitalists. Real capitalism implies no coercion or government protected oligopolies.

It is cushy and clubby? Yes. Is it capitalist? You betcha!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: WindyCity on 05/31/2014 09:44 pm
Well see that is the thing EM does not share the goals and responsibilities for defending the nation (AF) or science (NASA) he wants to make humanity a multi- planet species. And his accolytes will tell you that capitalism drives the whole thing, like as if capitalism doesn't drive Boeing. That's the really funny part.

In the case of Musk, I believe his idealism drives his company as much as the profit motive. If SpaceX doesn't receive the CCtCap grand prize, he stated that he would "soldier on" in Dragon V2's R&D. That means he would spend his company's, or his personal capital, on a product that didn't have an obvious buyer. That's bad business, no? It would seem to me that his true-believing "acolytes" would say something like this: "The Great and All-Powerful Musk will build a new branch of civilization on Mars, and profit be damned, leaving money-hungry, hidebound traditionalists in his gaseous wake." Yes, gaseous wake means exactly what you think it does.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space Ghost 1962 on 05/31/2014 09:49 pm
Back to why the "X" pattern of duplicate SD thrusters not being at 90 degrees.

You may be getting advantages:
 1. Less mechanical interference for parachute deploy from thruster housings
 2. More redundancy on entire thruster corner outage - you might compensate for the asymmetric thrust pattern with a complementary asymmetric throttling of the remaining 3.
 3. More "flight deck" visibility for vertical landings - crew arrangement is oriented around "long" axis in plane, can "look around" at windows.

What bothers me about this is the hypersonic stability of the system is like a asymmetric top, the passive stability is affected on ascent - it will act differently than Dragon 1 especially at Max Q. Fins?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 05/31/2014 09:56 pm

Lets not forget that the capsule can still do a "traditional" landing on water if the retropropulsion isn't to NASA's liking. If I understood correctly.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 09:56 pm


"Astronauts died not because they were using advanced technology.  Astronauts died because people ignored almost-accidents.  Both Shuttle accidents were preventable if middle managers would not have waived aside anomalies because the ultimate outcome was non-fatal."


You have missed the point while seeming to simultaneously cite it. Stating that we need not worry about hatches in heat shields because they didn't directly cause the shuttle failures, AS SEVERAL FOLKS HAVE REPEATED, is no better than saying, "well the scorched o rings didn't actually fail so we can still fly on them"  or "ice hasn't destroyed the heat shield before so it won't happen this TIME." But shuttle did use hatches in the heat shield and they have always been a cause for worry about thermal breeching and burn-through. That concern has been elevated enormously by the columbia burnthrough catastrophe,( even though the landing gear wells were eventually cleared as the cause..but many experts immediately focused on them as a potential cause specifically as the "logical" weak point, especially once bad telemetry originally indicated the gear door was opened during reentry.)  Hatches in the TPS do require greater attention and maintenance, as well as more actuation to utilize, and include a failure risk, mechanical and thermal, that NASA does not have to accept if it does not want to. Trivializing any addition of risk just does not cut it now. It is another tradeoff to consider.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CJ on 05/31/2014 10:01 pm
Not trying to denigrate Boeing or SNC at all, but how does CST-100 or DC even compare to Dragon V2?

Genuine question to people who know more technical specs on these spacecraft: Whats a feature or specification on CST-100 or DC that beats DV2 head to head?

I've been wondering about that as well, though in my case I've been thinking along the lines of the huge differences in LAS abilities. DC, for example, doesn't meet NASA's published human-rating guidelines because it doesn't have a full LAS. It can only separate from the LV after thrust termination; it can't boost free of an out of control LV, nor can it do a pad abort. (It can't, its two engines have nowhere near the thrust needed for those abort modes). Also, so far as I know, if it tried to land on water it'd be dicey at best from a survival POV. I have no qualms about DC having these limitations, but I wonder what impact this will have on selection.   

Another factor that might be (and surely should be) considered as one of the factors in selection is the launch vehicle problem for both DC and CST-100: Atlas 5. Specifically, the availability of its engine. I think it's clear that the RD-180 engine supply is at best uncertain. They could probably use Delta IV, but human-rating that LV would be a major and time-consuming undertaking at best.

As for a way DC or CST-100 has an ability beyond D2, DC has more crossrange ability, but that's the only one I can think of offhand. 

I see mentions in the thread of the hatches-in-the-heatsheild "issue". IMHO, this is a rather moot issue; DC has landing gear, and thus, like Shuttle, hatches in the heat shield (Shuttle also had ones for main engine fuel lines and also structural attach points that had to close in space or reentry would be unsurvivable, just like a landing gear deployment in space or during reentry would be unsurvivable - shuttle's gear could not retract in flight). CST-100 has air bags, which require either shield hatches or jettisoning the entire heat shield. (A heat shield that jettisons opens up failure modes, just as a hatch does). So, none of the three candidates has an unbroken, permanently attached heat shield.

I'm very concerned regarding the probable downselect, I personally strongly oppose the idea of downselecting to one provider, no matter which one. For both fiscal and reliability reasons (I'm old enough to remember both multi-year Shuttle flight hiatuses) I think going with one provider would be a very bad idea, but my guess is that's what they'll do. I hope I'm wrong.

If they do choose one provider, I think SpaceX is the closest to having manned capability, doesn't have the Atlas 5 Russian-engine problem, and costs less per seat, so would be the logical choice. I therefor think a downselect to one would probably result in picking Boeing as the CCP sole provider, because this decision, I fear, will be based more on politics than logic. I very much hope I'm wrong.

I was delighted to hear that Dragon 2 will fly whether they get axed from CCP or not.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 05/31/2014 10:18 pm
As for a way DC or CST-100 has an ability beyond D2, DC has more crossrange ability, but that's the only one I can think of offhand. 

That's a huge one.  DC can usually be on the ground at an airport in an hour, in an emergency.  It can always do it in 6 hours.  CST-100 and Dragon are more like 24-48 hours, typically.  In an emergency (think what would have happened if Luca had suffered secondary drowning due to the suit issue), that's an enormous difference.

Further, DC can enter without exceeding 1.5 times the force of gravity, while Dragon and CST-100 are going to be more like 4g's.  Again, that's a huge difference to some experiments, and to an injured astronaut.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/31/2014 10:21 pm


"Astronauts died not because they were using advanced technology.  Astronauts died because people ignored almost-accidents.  Both Shuttle accidents were preventable if middle managers would not have waived aside anomalies because the ultimate outcome was non-fatal."


You have missed the point while seeming to simultaneously cite it. Stating that we need not worry about hatches in heat shields because they didn't directly cause the shuttle failures, AS SEVERAL FOLKS HAVE REPEATED, is no better than saying, "well the scorched o rings didn't actually fail so we can still fly on them"  or "ice hasn't destroyed the heat shield before so it won't happen this TIME." But shuttle did use hatches in the heat shield and they have always been a cause for worry about thermal breeching and burn-through. That concern has been elevated enormously by the columbia burnthrough catastrophe,( even though the landing gear wells were eventually cleared as the cause..but many experts immediately focused on them as a potential cause specifically as the "logical" weak point, especially once bad telemetry originally indicated the gear door was opened during reentry.)  Hatches in the TPS do require greater attention and maintenance, as well as more actuation to utilize, and include a failure risk, mechanical and thermal, that NASA does not have to accept if it does not want to. Trivializing any addition of risk just does not cut it now. It is another tradeoff to consider.

Here's the differentiation as I see it.

In the case of openings through the TPS, the risk associated with them are considered during design.  So it is not "hand waving" to allow these risks.

In the case of foam hits, for example, there was no design that allows the shuttle to fly with holes in it.  Previous foam hits have caused damage, but were ignored, since the Shuttle survived.  That was the failing.

Not the acceptance of risk in the design.  It was the rejection of evidence of possible failure, because it wasn't proven.

So back to Dragon V2, I don't see the propulsive landing as a risk.  There's redundancy to the engines (just like on ascent) and even if the redundancy is exercised, that's by design.

But if, for example, two SD's fail when the DV2 is 10' above ground, and by luck the DV2 still manages to land on its feet, I wouldn't be saying "see?  it wall worked as planned, therefore the design was robust" - which is exactly what was done with STS, and in a recent conversation here, with the Soyuz abort scenario and LAS-till-orbit capability.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 05/31/2014 10:25 pm
As for a way DC or CST-100 has an ability beyond D2, DC has more crossrange ability, but that's the only one I can think of offhand. 

That's a huge one.  DC can usually be on the ground at an airport in an hour, in an emergency.  It can always do it in 6 hours.  CST-100 and Dragon are more like 24-48 hours, typically.  In an emergency (think what would have happened if Luca had suffered secondary drowning due to the suit issue), that's an enormous difference.


That's actually a misconception.  DC (and winged vehicles in general) have more cross range capability after they start aeordynamic flight, but all vehicles can execute a rather small phasing or lateral burn and within and orbit or two they've shifted their landing spot by hundreds of miles.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 05/31/2014 10:26 pm
I wonder, won't the superdracos be exposed to the hot reentry flow, especially when the capsule "steers" a little? Or can they easily handle it uncooled?

DC, for example, doesn't meet NASA's published human-rating guidelines because it doesn't have a full LAS. It can only separate from the LV after thrust termination; it can't boost free of an out of control LV, nor can it do a pad abort. (It can't, its two engines have nowhere near the thrust needed for those abort modes). Also, so far as I know, if it tried to land on water it'd be dicey at best from a survival POV. I have no qualms about DC having these limitations, but I wonder what impact this will have on selection.   

CST-100 has air bags, which require either shield hatches or jettisoning the entire heat shield. (A heat shield that jettisons opens up failure modes, just as a hatch does).

I'm afraid DC won't win because of some of the reasons you mention.

CST-100 drops the entire shield when it hangs in the chutes, like Soyuz and many other reentry vehicles have.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Halidon on 05/31/2014 10:47 pm
Ike, apologies but I'm having a hard time understanding your mini-crusade against Dragon V2's landing legs deploying through the heat shield. DC deploys its landing gear through "hatches" in the aircraft's thermal protection system just as I believe the vast majority of spaceplanes built or envisioned have. And while CST-100's heat shield remains in one piece, as with Soyuz exposing its landing thrusters the entire thing must be jettisoned cleanly for the air bags to deploy. If "thou shalt not muck with the TPS" is one of your spacecraft commandments, I'm afraid you are grounded.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 10:53 pm
>>we keep hearing about who is "ahead" or who is "closest to complete." I don't think this frames the issue correctly as the process has set milestones and deadlines that get everyone there. We don't halt the Indy 500 at mile 250 because we know who is ahead...The real question being asked throughout this phase  is "are they able to track well enough in meeting milestones and to continue achieving milestones ON SCHEDULE based on what we know?"  Now, If there is an early downselect the focus on measurement of progress may change. Who has more milestones met is important, and yet, maybe not all that matters.  If Space X adds more development risk by introducing new technologies, then are they really ahead by being on schedule or even ahead of schedule?  Schedule risk will be near the top of NASA's concerns.  In an early downselect scenario, The solution of leaning on tried-and-true may actually trump everything else. A contender who appears to be "behind" could get the nod if the steps in front of them involve less uncertainty. This is why the declarations of who is "ahead" probably mean less than i believe a lot of folks think.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 05/31/2014 10:56 pm
I think it's been very educational. For instance, I learned that if you aren't afraid of propulsive landings with a parachute backup, you're a fanboi. I also learned that that the term "tried and true" technology only applies to technologies not included in the Dragon, once a technology is in the Dragon, it's scary and has only ever worked because of luck. Decades and decades of luck. I've learned that rather than take the word of people investing all their time and money in something, you should make up conspiratorial "real reasons and motivations" for their actions. I've also learned that being excited about something that someone else is not excited about makes you delusional and that the rational thing to do is go to a forum full of people excited about that thing and call them names, concern troll and generally be abusive "for their own good."

Best party thread ever.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: douglas100 on 05/31/2014 11:06 pm

That's actually a misconception.  DC (and winged vehicles in general) have more cross range capability after they start aeordynamic flight, but all vehicles can execute a rather small phasing or lateral burn and within and orbit or two they've shifted their landing spot by hundreds of miles.

Dragon has cross range ability, but it achieves it aerodynamically, like DC does, but DC has better cross range than Dragon. To make up the difference propulsively  would take quite a bit of extra prop, since you would have make the burn out of plane.

However, I don't think DC's extra cross range ability is as great a selling point as has been made out. It would be a more comfortable ride, but if there were a medical emergency requiring bringing a crew member back rapidly to Earth, I doubt any of the VV's could do it within 2 hours. It's a very unlikely scenario anyway, IMO.

This point came up earlier, and I wanted to raise it again. Having eight SuperDracos firing with just the wall between them and  the crew makes for a very noisy environment indeed. Without good protection I think there would be serious risk of ear damage. The metal isogrid wall shown during the V2 reveal would of course be covered by some kind of insulation. What would be enough? Would noise cancelling ear protectors be good enough in such a severe acoustic environment?

I think acoustically, I'd rather ride in DC!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 05/31/2014 11:08 pm


Saying that hatches in the heat shield is some type of new risk is just wrong. It might be a risk, but look at the shuttle. It NEVER failed from the wheel well seams in the heat shield. It failed from a piece debris knocking off a tile that cause disintegration of the craft. It never failed at the wheel well.



No one said it is a new risk. It was stated that the risk is receiving renewed attention from NASA POST columbia.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rcoppola on 05/31/2014 11:27 pm


>>Roughly speaking, my point is that Space X enthusiasm (bordering on blind fanaticism for some) is no excuse for ignoring that v-2 is far from the "leading" or "obvious winner" among the entrants BECAUSE IT SEEMS TO BE AIMING AT A DIFFERENT GOAL.  V-2 represents quite a departure from the Ccdev selection process's original intent. It's an exciting vehicle for sure. But it has a ways to go in developmental cycle with lots of question marks, and it does not reflect what NASA Has stated as its goal: a quick-build, reliable , proven technologies-based taxi service to ISS by 2018.  Candidly, DC is a stretch as well, but it has enough shuttle heritage and NASA likes the winged option as an alternative to capsule.  I agree with many that Boeing is the safe choice to ensure we have an ISS taxi by 2018, but i hope Space x and Sierra Nevada can find markets and missions for their fine vehicles as well.

As written by NASA: "The objective of the CCP is to facilitate the development of a U.S. commercial crew space transportation capability with the goal of achieving safe, reliable and cost-effective access to and from the International Space Station and low Earth orbit."

Safe, reliable and cost-effective. However, schedule has increasingly become a priority as well for obvious reasons.

Let's rationally try to take these one at a time. (Although not in excruciating detail and feel free to add subtract and be prepared to have this moved into a more appropriate thread)

1. Safety - Each system has risks to retire. i.e. Avionics, Pusher escape systems, TPSs, airbags, propulsive landing, non-powered controlled flight landings etc. (For the record, according to NASA, DC in the last round of funding was considered to have the most risk to retire before becoming fully operational)

But of all 3 systems, SpaceX has actually demonstrated, multiple times, successful reentry with core technologies such as  their PICA-X TPS, avionics and Draco thrusters. (not including Dragon's currently proven pressure vessel as that will undergo more stresses in the new design)

SpaceX has done one successful test of their new quick-releaase parachutes, CST-100 has done a successful airbag test and DC one autonomous free-flight and landing.

SpaceX has qualified their Super Draco abort and propulsive landing engines through a rigorous testing regimen. They have 30 tests lined up in TX with DragonFly to prove out the software / hardware over the next year as well as both Pad and in-flight abort tests. Again mitigating more risk. (I am unaware of a robust abort testing schedule from either Boeing or SNC at this time. Please fill it in if you know)

Net, net, through current flight hardware and software and a more transparent and robust plan for testing design ready hardware, I find it hard to understand how SpaceX could be considered as having to reduce more risk then systems that have no "Current" orbital flight experience.

2. Reliability:  I'm not comfortable rendering an opinion on that quite yet. That needs to be assessed once these systems are operational. IMO.

3. Cost-effective: Having a robust commercial launch manifest, almost complete vertically integrated design, production and operations, an inexpensive launcher, an inexpensive-long term lease with modification plans wrt Pad 39A, SpaceX is most likely able to offer the most cost effective CCP proposal.

4. Schedule to market: Each company feels confident they can make the 2017 deadline, although determinative of funding levels. So the real question may become, who can get there first and least expensively. (All systems have a lot of work to do, no question about it.)

SpaceX, by their own account, says the vehicle we just saw, D2, is flight design hardware and will go orbital in 2015. Crewed flight and subsequently fully operational in 2016.

Boeing as of a few weeks ago said they are receiving parts at their KSC assembly facility, from hundreds of subcontractors from around the country and continue to build their initial flight design vehicle.

SNC has contracted Lockheed Martin to build the first actual flight design DC. Latest is it is taking shape and looking like a real spacecraft.

So net-net, it would seem, that although indeed Dragon V2 departs enough from D1 to be considered a new development and flight vehicle, risk mitigation with regard to key enabling technologies have either already been significantly reduced through D1 operations or will be reduced from a robust and timely testing regimen.

However, in all fairness, I can not properly do a one-to-one comparison of risk mitigation and schedule as neither Boeing or SNC have outlined what SpaceX has wrt their DragonFly, abort and orbital testing programs. Perhaps that in and of itself says something about SpaceXs confidence in their proposal.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jtrame on 05/31/2014 11:47 pm
This is the third worst party I've ever been to.
I think it's been very educational. For instance, I learned that if you aren't afraid of propulsive landings with a parachute backup, you're a fanboi. I also learned that that the term "tried and true" technology only applies to technologies not included in the Dragon, once a technology is in the Dragon, it's scary and has only ever worked because of luck. Decades and decades of luck. I've learned that rather than take the word of people investing all their time and money in something, you should make up conspiratorial "real reasons and motivations" for their actions. I've also learned that being excited about something that someone else is not excited about makes you delusional and that the rational thing to do is go to a forum full of people excited about that thing and call them names, concern troll and generally be abusive "for their own good."

Best party thread ever.

Perhaps because a "discussion thread" is to be a discussion, not a circle jerk.

I think mme made a good point.  Regardless or whether this is a discussion thread or party thread, if you take in the entire history of the thread there is probably (IMO, YMMV) way too much hubris being thrown back and forth.  And in your defense, you haven't been treated very well on the quoting issue.  But both typical in my experience on this forum.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: r4mir3zx on 05/31/2014 11:56 pm
Just something on risk. The very first men who got off the trees and headed for the savannah, took a risk that the others didn't. Latters still are on the trees in Africa (or in some zoo around the world). Colombus took the risk to head for west with his fragile tiny boats, found America and some hundred years for Spain to be one of the powers of the world. Pilgrims took the risk to settle in a completely new and hostile world without being sure they would stay alive even after the first winter. All the history tells us stories of people taking risk - of course, the clever way - and earning the reward.

OTOH this, of course doesn't mean that it shouldn't be done anything to reduce the risk, of course. e.g.: Colombus started with 3 ships instead of 1, etc.

And even the Apollo Project was a huge risk itself, but it earned much - without it now we wouldn't discuss about the risk NASA would take selecting Dragon over CST-100 or DC. So if NASA still what is it for - exploration and about to widen the boundaries of Humanity - then it won't achieve its goals without taking some risk and with overthinking. Just look at the last ~20 years. No competition, no taking risk. No american human space access. (trampoline?) So I think with taking the risk now SpaceX is what sometime in the 1960s NASA was.

Just an outsider opinion - or a amazing people opinion maybe :D. Of course I know this sounds a little bit ideological and maybe naive, but this is an aspect, too. BTW I would like to see all the three vehicle to fly and mostly to evolve, and compete each other. That would be the best for NASA and for the human space projects.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Carl G on 05/31/2014 11:58 pm
Looks like a number of mods have trimmed this thread, but I'll add the warning.

Yes, this includes a party thread, but you must still think before posting. Quotes need to be "reply with quote" by quoting the post you are responding to, otherwise the whole thread breaks. Images should be attached, not embedded. Any post with a width breaking embedded image will be deleted.

Thread trimmed of nonsense and pointless posts, and posts responding to such posts.

100,000 views for this thread. The quality is not good enough in parts. We have increased the quality with a trim.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 12:01 am
As for a way DC or CST-100 has an ability beyond D2, DC has more crossrange ability, but that's the only one I can think of offhand. 

That's a huge one.  DC can usually be on the ground at an airport in an hour, in an emergency.  It can always do it in 6 hours.  CST-100 and Dragon are more like 24-48 hours, typically.  In an emergency (think what would have happened if Luca had suffered secondary drowning due to the suit issue), that's an enormous difference.

Not true.  In an emergency, Dragon V2 can land on any body of water at all or anyplace on land where there's a flat spot, such as the parking lot of any hospital on the planet.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 06/01/2014 12:05 am
Wrong again.

Wrong

wrong, see above.

wrong again.

Wrong again,

Wrong.

It'd be a fun drinking game if it wasn't so tiresome.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 06/01/2014 12:07 am
As for a way DC or CST-100 has an ability beyond D2, DC has more crossrange ability, but that's the only one I can think of offhand. 

That's a huge one.  DC can usually be on the ground at an airport in an hour, in an emergency.  It can always do it in 6 hours.  CST-100 and Dragon are more like 24-48 hours, typically.  In an emergency (think what would have happened if Luca had suffered secondary drowning due to the suit issue), that's an enormous difference.

Not true.  In an emergency, Dragon V2 can land on any body of water at all or anyplace on land where there's a flat spot, such as the parking lot of any hospital on the planet.
Chris, we might have to be a bit careful with hypergolics on board...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 12:08 am
The inherent weaknesses of the shuttle systems are exactly why we are havin this debate at all.  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.if there is a newfound emphasis on safety and simplicity/ reliability,specifically in the wake of a catastrophic burnthrough, this should not be a surprise. It is added risk.

Nonsense.  Provide a reference that says NASA has ever, even once, rejected a design in whole or in part because of hatch openings.

More amazing people excuse making and dismissing of risk. This is how NASA GOT ASTRONAUTS KILLED.  It seems someone learned something from these tragedies, but a lot of folks are still very capable of fooling themselves.  Propulsive landing is difficult, never mind he hatches issue. It involves serious tradeoffs of weight and fuel. Parachutes are lighter and simpler.  if Elon wants a higher risk craft, that is his right. But it is NASA's right to choose something old school and maybe a bit too boring for the armchair enthusiasts who are fixated on the "cool factor" of propulsive landing.

More nonsense.  "Different from before" does not equal "riskier".

Parachute landings have a lot of risk.  They can fail to deploy at all.  They can deploy and then get tangled.  Even if they deploy and don't get tangled, the craft can be carried by wind to an unpredictable landing site.  This doesn't matter if landing in the water, but then landing in the water has additional risks.

Propulsive landings haven't been done much, so there is design risk that needs to be retired, but SpaceX plans to do that with many flights of DragonFly.  Once that testing has been completed, and given that parachutes are still available as a backup, it seems to me propulsive landings are much less risky than parachute landings.

I'll say this much: SpaceX are taking an enormous risk with this strategy. Dragon-2 is different enough from Dragon-1 to be considered untested and this could give NASA grounds to deny it the Commercial Crew missions.

>>i tried to make this point and the knives came out. Don't let facts get in the way, i guess.

No, the facts are not on your side here.  There are some significant new things in Dragon V2, but there are also some significant carry-overs from Dragon V1.  So Dragon V2 is partly tested, not untested.  And that's a lot better than either of its competitors, neither of which has had a V1 tested in orbital flight at all.

V-2 is a shot-in-the-dark and is going to be a hard sell.

>>yes, the amazing peoples are forgetting that the buyer is NASA. Not the attendees at the next Star Trek convention. The fact is, its a very different animal than v-1. Space x has proven they are great with launchers. A crew vehicle is a success by getting its crew where they need to go and back safely. Space X so far, has zero experience on that, and putting a new vehicle into the field is more of a reset than some folks here apparently are able to admit to themselves.  Frankly, DC, because of its HL-20 heritage seems to be a more known product than the " tesla in the sky" approach.


SpaceX just seems to be rushing ahead and causing themselves difficulties because of it...Maybe I'm too cautious but this strikes me as taking a bit too much of a risk for the sake of taking a risk.

>>nasa us looking to reduce risk. And frankly, musk does himself no favors by the nasa bashing.  They are paying for the bulk of his venture.

 Elon strikes me as more and more a ...wild, daredevil personality who is never happier than when taking enormous technical and personal risks out of a combination of adrenaline addiction and a desire to prove himself able to outsmart the entire world.

>>he may outsmart himself. LET HIM BUILD AND FLY HIS TOY. But NASA is looking to hire a taxi to LEO.  This presentation only further convinces me that the way forward is for a full award to Boeing for crew vehicle but exploring their idea or letting Space X do what it has proven it does well -- providing launch service for that vehicle, and continue driving costs down, while a developmental award goes to DC  to get us a winged option further down the road.

You really don't have any evidence to back up any of this.  Everything you've said comes down to your personal opinions about SpaceX.  These opinions are at odds with everything SpaceX has accomplished so far.  If Elon Musk is simply a wild daredevil, how has Cargo Dragon successfully been resupplying the ISS?  How has Falcon 9 been successfully putting payloads into orbit?  How did SpaceX soft-land a first stage?  How did SpaceX win a NASA CCDev contract?  How did they pass all their intensive reviews of their CCDev entry by NASA?  Why did NASA lease them LC39A for 30 years?

All the actual evidence conflicts with your opinions.

Roughly speaking, my point is that Space X enthusiasm (bordering on blind fanaticism for some) is no excuse for ignoring that v-2 is far from the "leading" or "obvious winner" among the entrants BECAUSE IT SEEMS TO BE AIMING AT A DIFFERENT GOAL.  V-2 represents quite a departure from the Ccdev selection process's original intent.

Not at all.  The intent of CCDev was to create a system to transport crew to and from the ISS as safely and cheaply as possible.  Dragon V2 seems to be an excellent system for doing just that.

It's an exciting vehicle for sure. But it has a ways to go in developmental cycle with lots of question marks,

It's farther along in its development cycle than any of the other CCtCap hopefuls.  It's set to do a launch abort test later this year and a max-Q abort test not long after that, with an uncrewed orbital flight next year, with the very same hardware Musk showed off this week.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 06/01/2014 12:09 am
SpaceX's proven history with NASA flying Dragon V1 likely gives them a huge advantage in this 3 way competition. I will be shocked if SpaceX is not picked as the winner.

In terms of generating interest in space, Boeing and Dream Chaser will be huge disappointments. I can imagine the hate mail that NASA will get if they don't pick SpaceX Dragon V2. Does anyone think the same level of NASA hate would happen by Boeing or Dream Chaser losing? So does a tie go to SpaceX in this competition? :-) I am sure that will be a topic of discussion in this process. It may not be on the official list of items to evaluate, but it will be discussed.

SpaceX wins the tie because of the extra public interest in space they bring to the table. No bucks without Buck Rogers / Iron Man (aka Elon Musk). Just my opinion.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 12:10 am
As for a way DC or CST-100 has an ability beyond D2, DC has more crossrange ability, but that's the only one I can think of offhand. 

That's a huge one.  DC can usually be on the ground at an airport in an hour, in an emergency.  It can always do it in 6 hours.  CST-100 and Dragon are more like 24-48 hours, typically.  In an emergency (think what would have happened if Luca had suffered secondary drowning due to the suit issue), that's an enormous difference.

Not true.  In an emergency, Dragon V2 can land on any body of water at all or anyplace on land where there's a flat spot, such as the parking lot of any hospital on the planet.
Chris, we might have to be a bit careful with hypergolics on board...

That's true.  We wouldn't want to land in a parking lot on a routine basis.  But we're talking about an emergency here, where someone needs to get to a hospital in an hour or he or she is likely to die.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 12:21 am
Can we turn this back into a party?

To me, the question of 2 DreamChaser missions a year to ISS versus 2 CST-100 missions a year to ISS versus 2 Dragon V2 missions a year to ISS isn't interesting enough to have a party about.  It's still 2 missions a year.  Do we really not aspire to more than that, 50 years into the space age?

Dragon V2 is exciting because it is built on the premise of more than 2 missions a year.  It's built on the premise that it can be used over and over.  It's built on the premise that it doesn't take long to go from landing to re-launch.  It's built on the premise of using a launcher that is itself quickly and cheaply reusable.  It's built on the premise of taking many people to and from space, and taking them often.

Now that is worth partying about!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 12:28 am
The windows remains enigmatic to me. No need when you have cameras and displays, little added value for space tourism.

1. By that logic, the Cupola is criminal. There is such a thing as crew morale.
2. Mike Foale, Valery Korzun Vasily Tsibliyev and Sasha Lazutkin apparently have something to say about that.

Humans literally develop with an oval window in their hearts. And there's one in your head (http://en.wikipedia.org/wiki/Foramen_ovale) and another one in your ear (http://en.wikipedia.org/wiki/Oval_window). It's part of who we are. So it's natural that it would find its way into what we make. (Especially given that the no-corners shape doesn't introduce any structural problems, and, as someone else said, the window allows good downrange visibility - along the major axis - during docking)

Seriously? Windows in hearts and ears, relevant how? Eyes are windows, not exactly cameras with the visual processing exactly as virtual screen?

Then I'm taking back the obviated need for references re windows in planes. Did they really compare with camera and screens as windows?

Same goes for ISS, I would assume other windows are small et cetera, and it was more awesome to install windows instead of the same perspective with surround screens. Which gets me back to the "little added value" enigma.

Sure, we have a long history of windows. We had a long history of sending letters too. YMMV.

Quote
- Quick test shows my smartphone is eminently capable of distinguishing between hardware bumps and intended pushes or slides. Likely by the acceleration profile alone, which is also how some softwares distinguish individuals. (Admittedly from longer interaction, often writing tasks, but affirming the principle.)

As I understand it SpaceX has freedom to choose the technology, and reusing Tesla technology (like for the batteries) would be their rapid development, cheap production pathway. I therefore assume we saw all the controls there ever will be.

Orion is going to be going BEO, through the Van Allen belts, and staying outside them. If something goes wrong, it's not a quick ~hour ride back to safety. They've to be able to fix that stuff there. Neil and Buzz would still be on the moon if they'd used touch-screens and the software broke.

"Software broke"!?

And by the way, as if it takes longer to patch software remotely than to send the missing screw from Earth. =D

Interesting point on radiation vs new technology. Touch screens work capacitively (e.g. the iPhone) which is likely far less sensitive to radiation than the processors that the hardware controls. (More precisely, the screen capacitances should be much larger than the CMOS ones so need more radiation to bit flip. But I'll have to check that.)

That said, I'm not against introducing modern technology. NASA has that freedom too.. but they'd rather let SpaceX qualify the modern technology on SpaceX's dime - if the latter are willing to do it anyway.

As long as we agree that, due to the long development time and the absence of keeping up with new technology, Orion is not only not state-of-the-art, it is obsolete and in need of catching up at best.  :D

Plus, if two things are going to weigh the same, then I'd pick a redundant system that doesn't share failure modes with my backup. I'd duplicate only IF such a system was unavailable, or much heavier. Extra-wiring + mechanical switches (for critical functions) cost ~< mass of more touch screens.

"More" touch screens? They will want to use all of them. If nothing else, it saves on weight when they need to play Kerbal during delays.

I think software guys have a different outlook on backup. The number of backup processors and threads on that thing (F9R + Dragon) is unprecedented, and 3 backup screens are 2 backups more than just "my [one] backup".

Again, I don't think customer preference weighs heavily on details but on service delivered. Think of CC as choosing between rental car services, not as between cars to buy.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 06/01/2014 12:29 am
It's built on the premise of taking many people to and from space, and taking them often.

Now that is worth partying about!

I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market. So far as I've heard, it's all government space agency customers, all the time. So far as I've heard, NASA remains opposed to private astronauts riding along to the ISS. So far as I've heard, SpaceX isn't interested in space tourism. I have no doubt that at least one of these things I've heard is wrong - I just wish SpaceX would set us straight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DMeader on 06/01/2014 12:41 am
In terms of generating interest in space, Boeing and Dream Chaser will be huge disappointments. I can imagine the hate mail that NASA will get if they don't pick SpaceX Dragon V2. Does anyone think the same level of NASA hate would happen by Boeing or Dream Chaser losing? So does a tie go to SpaceX in this competition? :-) I am sure that will be a topic of discussion in this process. It may not be on the official list of items to evaluate, but it will be discussed.

That isn't the mission. The objective of all this is to find an affordable way for the US to get crews to LEO. If Boeing or DC wins, extremely avid SpaceX fans are the only persons NASA will get hate mail from.

SpaceX wins the tie because of the extra public interest in space they bring to the table. No bucks without Buck Rogers / Iron Man (aka Elon Musk). Just my opinion.

And that isn't the mission either. You've reduced the whole thing to nothing more than a PR exercise.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 12:45 am
It seems overwhelmingly reasonable to me that many unresolved technical issues remain to be dealt with before SpaceX will be ready to fly its new capsule. It wouldn’t surprise in the least if significant changes to its design cropped up over the next two years involving the hatch, the oval windows, the landing legs, the instrument panel, the couches, and the dock cover, just to name a few. It would be a gross mistake, in my opinion, to look at the craft that went on display the day before yesterday as a finished product.

I think you're not aware of how many design iterations and reviews Dragon V2 has already gone through, including a number of reviews with NASA.  These reviews are part of NASA's CCiCap milestones.  The way they work is NASA sends dozens of experts to SpaceX and SpaceX presents their designs in great detail.  The NASA personnel ask any questions they want, and SpaceX's answers have to satisfy them.  Until each and every NASA participant has been satisfied by the answers, the milestone isn't complete and SpaceX isn't paid for it.

SpaceX's Dragon V2 has successfully passed a Ground Systems and Ascent Preliminary Design Review, a Pad Abort Test Review, a Human Certification Plan Review, an On-Orbit and Entry Preliminary Design Review, and In-Flight Abort Test Review, and a Safety Review.

The Dragon V2 revealed this week wasn't the start of a long design process, it was the culmination of a long design process.  The revealed article is the one built to be sent into orbit for the first uncrewed orbital test sometime next year.

http://www.parabolicarc.com/2014/02/26/spacex-commercial-crew-milestone-status-february/
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 06/01/2014 12:47 am
Wrong again.

Wrong

wrong, see above.

wrong again.

Wrong again,

Wrong.

It'd be a fun drinking game if it wasn't so tiresome.

Without Jim the quality of this forum would be considerably lower. We should be thankful for his corrections.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/01/2014 12:51 am
It's built on the premise of taking many people to and from space, and taking them often.

Now that is worth partying about!

I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market. So far as I've heard, it's all government space agency customers, all the time. So far as I've heard, NASA remains opposed to private astronauts riding along to the ISS. So far as I've heard, SpaceX isn't interested in space tourism. I have no doubt that at least one of these things I've heard is wrong - I just wish SpaceX would set us straight.

From the SpaceX Press Center (http://www.spacex.com/press/2012/12/19/spacex-and-bigelow-aerospace-join-forces-offer-crewed-missions-private-space)
Quote
MAY 10, 2012

SPACEX AND BIGELOW AEROSPACE JOIN FORCES TO OFFER CREWED MISSIONS TO PRIVATE SPACE STATIONS

And while not a Dragon mission, Bigelow is on the manifest (http://www.spacex.com/missions)

Quote
BIGELOW AEROSPACE   CAPE CANAVERAL    FALCON 9

I assume we'll hear more when there's more to hear. My assumption is that SpaceX will be glad to support the space tourism market, but are not interested in creating that market themselves.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 06/01/2014 12:53 am
And while not a Dragon mission, Bigelow is on the manifest (http://www.spacex.com/missions)

.. and? Bigelow is aiming at the foreign space agency market.

I assume we'll hear more when there's more to hear. My assumption is that SpaceX will be glad to support the space tourism market, but are not interested in creating that market themselves.

Which is the same as saying they're not saying anything, which is what I said.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jabe on 06/01/2014 12:55 am
It's built on the premise of taking many people to and from space, and taking them often.

Now that is worth partying about!

I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market. So far as I've heard, it's all government space agency customers, all the time. So far as I've heard, NASA remains opposed to private astronauts riding along to the ISS. So far as I've heard, SpaceX isn't interested in space tourism. I have no doubt that at least one of these things I've heard is wrong - I just wish SpaceX would set us straight.
Robert Bigelow was at the unveiling so some behind the scenes discussions must be going on..no point asking him to show up if there was no interest in other markets.. and for Spacex to make their own spacesuit also shows other interest than just Nasa..well in my view :)
but it would be nice for spacex to  "set us straight"
jb
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 12:56 am
It's built on the premise of taking many people to and from space, and taking them often.

Now that is worth partying about!

I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market. So far as I've heard, it's all government space agency customers, all the time. So far as I've heard, NASA remains opposed to private astronauts riding along to the ISS. So far as I've heard, SpaceX isn't interested in space tourism. I have no doubt that at least one of these things I've heard is wrong - I just wish SpaceX would set us straight.

From the SpaceX Press Center (http://www.spacex.com/press/2012/12/19/spacex-and-bigelow-aerospace-join-forces-offer-crewed-missions-private-space)
Quote
MAY 10, 2012

SPACEX AND BIGELOW AEROSPACE JOIN FORCES TO OFFER CREWED MISSIONS TO PRIVATE SPACE STATIONS

And while not a Dragon mission, Bigelow is on the manifest (http://www.spacex.com/missions)

Quote
BIGELOW AEROSPACE   CAPE CANAVERAL    FALCON 9

I assume we'll hear more when there's more to hear. My assumption is that SpaceX will be glad to support the space tourism market, but are not interested in creating that market themselves.

I agree.  I see it as analogous to the satellite launch market.  Their short-term plan is to serve the already-existing market, but by lowering costs greatly, they hope to stimulate the development of a much larger market.  In human spaceflight, the existing market is only the government, so they will first serve that market, but by lowering costs, they hope to spur a greater market.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 01:06 am
Robert Bigelow was at the unveiling so some behind the scenes discussions must be going on..

That's an excellent sign!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 01:09 am
If today a down select were forced by congress to a single provider the choice would go to CST100(Orion) because that program has the political momentum to sustain it.

Except that CST-100 and Orion are totally different capsules being built by different companies.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Coastal Ron on 06/01/2014 01:12 am
Robert Bigelow was at the unveiling so some behind the scenes discussions must be going on..

That's an excellent sign!

Well we have to remember that Bigelow already quotes prices for using SpaceX to get customers to their private stations (Boeing too), so Bigelow has already done about as much as he can at this point - he's waiting for at least two certified crew transportation systems so that he can start his space station service.

And what happens with Bigelow if only one provider is certified by NASA?  I'm sure he's thought about it, but we won't know the answer publicly until that happens.  Let's hope Congress provides enough funding for at least two operational crew transportation systems...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 06/01/2014 01:16 am
There has been a bit of discussion lately about the risks of the Dragon V2 vis a vis the upcoming NASA competition.    I really liked the new design of Dragon V2 - it looks like a logical, progressive update of Dragon V1.  That said, the comments stating that the new approaches (propulsive landing, different aerodynamics, pop out landing pegs, etc..) DO raise risks for the competition compared to a modest update to a 4X flight proven article.  (I do think they are reasonable risks, though).  So, based on that, I think the real question here is: 

Why is SpaceX taking additional risk with a substantially different D2 vs. D1 for a human rated system?

I can think of a few possibilities, some or all of which may be true (or not):

1. SpaceX thinks a man-rated D1 isn't going to be competitive with the Boeing/Sierra Nevada bids

2. SpaceX wants to win with a much superior design and this superiority makes the new development risk worth it. (though they have been vetting designs during milestones with NASA).

3. SpaceX doesn't really care that much about NASA because they want this design for their own purposes.  (at least one of the two suppositions here is definitely true).

4. There may be more in common with D1 vs. D2 than we realize from SpaceX's take on NASA's perspective.

5. That big trunk!  What could you do if it were beefed up inside?  Could they be competing with Orion beyond short term?

6. Commonality of approach with their reusable rocket infrastructure and logistics.

7. Your reason here..............................
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/01/2014 01:22 am
And while not a Dragon mission, Bigelow is on the manifest (http://www.spacex.com/missions)

.. and? Bigelow is aiming at the foreign space agency market.

I assume we'll hear more when there's more to hear. My assumption is that SpaceX will be glad to support the space tourism market, but are not interested in creating that market themselves.

Which is the same as saying they're not saying anything, which is what I said.

From the (admittedly two year old) press release (http://www.spacex.com/press/2012/12/19/spacex-and-bigelow-aerospace-join-forces-offer-crewed-missions-private-space) in my original response:
Quote
Hawthorne, CA, and Las Vegas, NV– Space Exploration Technologies (SpaceX) and Bigelow Aerospace (BA) have agreed to conduct a joint marketing effort focused on international customers. The two companies will offer rides on SpaceX’s Dragon spacecraft, using the Falcon launch vehicle to carry passengers to Bigelow habitats orbiting the earth.
I wasn't trying to contradict you, just pointing out that unless something has changed, SpaceX and Bigelow already publicly announced they intend to use the Dragon.  I don't understand why it matters if they are "international customers," sorry if I'm being dense.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 01:22 am
Well we have to remember that Bigelow already quotes prices for using SpaceX to get customers to their private stations (Boeing too), so Bigelow has already done about as much as he can at this point - he's waiting for at least two certified crew transportation systems so that he can start his space station service.

Waiting for NASA to certify two crew transportation systems isn't "about as much as he can at this point".  If he really wanted to, he could sign a contract with one or more crew transport providers.  If there were really a lot of demand for Bigelow's stations, it's hard to believe he would just sit around and wait for NASA, and leave money on the table in the meantime.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 01:23 am
Wrong again.

Wrong

wrong, see above.

wrong again.

Wrong again,

Wrong.

It'd be a fun drinking game if it wasn't so tiresome.

Without Jim the quality of this forum would be considerably lower. We should be thankful for his corrections.

I would like to say "wrong, see above". But that is likely a loosing proposition.  :o
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Coastal Ron on 06/01/2014 01:24 am
In terms of generating interest in space, Boeing and Dream Chaser will be huge disappointments. I can imagine the hate mail that NASA will get if they don't pick SpaceX Dragon V2. Does anyone think the same level of NASA hate would happen by Boeing or Dream Chaser losing? So does a tie go to SpaceX in this competition? :-) I am sure that will be a topic of discussion in this process. It may not be on the official list of items to evaluate, but it will be discussed.

That isn't the mission. The objective of all this is to find an affordable way for the US to get crews to LEO. If Boeing or DC wins, extremely avid SpaceX fans are the only persons NASA will get hate mail from.

Good reminder - the goal is affordable transportation to LEO, and ideally we want that to be a redundant transportation system with at least two providers.

I'm a big SpaceX fan, and I also think that there is only a small chance that SpaceX will not be awarded some amount of money for the CCtCap program.  But because the NASA COTS and Commercial Crew contract awards have been pretty well decided recently, and they have provided background on how they arrived at their decisions, I'd hope that if for some reason SpaceX did not get a contract - and the reasons were non-political and merit based - that I would accept the results.

But as of today I think there is only a slim chance that SpaceX won't get a CCtCap contract.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/01/2014 01:24 am
I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market.

Don't forget Elon's not-so-subtle "single digit millions if volume is high enough" statements.  I don't think he'd be saying that unless he thought there was a chance the volume might actually increase.  And I think we can all agree that NASA is only thinking 4 missions/year max.  So, coupled with Bigelow's presence...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 01:27 am
I would like to say "wrong, see above". But that is likely a loosing proposition.  :o

Wrong again. It's a losing proposition
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/01/2014 01:31 am
Trying to make more of a party here:

Anyone here wonder what Elon might fly on the first Falcon Heavy flight?  I don't remember hearing about a (brave) customer for it, yet, although Elon has hinted that they're still willing to entertain a "last minute" paying customer.  But it doesn't seem SpaceX's style to send up another mass simulator.  Any chance we might see a Dragon v2 with some mouse-tronauts thrown on a lunar free return trajectory?  Or another mars shot?  Given the topic of this thread, let me hear some creative Dragon V2 long shots!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 01:32 am
Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction. 

And that's a really good point.

Imagine what would happen if NASA rejected the design because of the retrorocket approach? That would be a conservative engineering decision, but I suspect that it might result in a lot of kvetching here...
If NASA communicates that to SpaceX, then SpaceX merely has to go back to parachutes and splashdown, which Dragon v2 is certainly still capable of (and was recently tested). And parachutes and splashdown are the most conservative approach of any of the landing methods. So that is no problem at all.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Coastal Ron on 06/01/2014 01:34 am
Well we have to remember that Bigelow already quotes prices for using SpaceX to get customers to their private stations (Boeing too), so Bigelow has already done about as much as he can at this point - he's waiting for at least two certified crew transportation systems so that he can start his space station service.

Waiting for NASA to certify two crew transportation systems isn't "about as much as he can at this point".  If he really wanted to, he could sign a contract with one or more crew transport providers.  If there were really a lot of demand for Bigelow's stations, it's hard to believe he would just sit around and wait for NASA, and leave money on the table in the meantime.

If Bob Bigelow were more like Elon Musk maybe he would be more proactive, but I think we're all forgetting how much money this has already cost him and how much more it will take before he starts generating revenue (much less profit).  And without crew transportation he has no business.

So I don't blame Bob Bigelow for not doing more, since besides Elon Musk he has been the most pro-space business person in the world (Branson is only sub-orbital, and no one knows what goals Bezos has for space).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 01:35 am
Trying to make more of a party here:

Anyone here wonder what Elon might fly on the first Falcon Heavy flight?
We did a thread on that (http://forum.nasaspaceflight.com/index.php?topic=24734.0) a long time ago. My vote remains on a yellow bulldozer, christened "Prostetnic Vogon Jeltz"
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 01:39 am


"Astronauts died not because they were using advanced technology.  Astronauts died because people ignored almost-accidents.  Both Shuttle accidents were preventable if middle managers would not have waived aside anomalies because the ultimate outcome was non-fatal."


You have missed the point while seeming to simultaneously cite it. Stating that we need not worry about hatches in heat shields because they didn't directly cause the shuttle failures, AS SEVERAL FOLKS HAVE REPEATED, is no better than saying, "well the scorched o rings didn't actually fail so we can still fly on them"  or "ice hasn't destroyed the heat shield before so it won't happen this TIME." But shuttle did use hatches in the heat shield and they have always been a cause for worry about thermal breeching and burn-through. That concern has been elevated enormously by the columbia burnthrough catastrophe,( even though the landing gear wells were eventually cleared as the cause..but many experts immediately focused on them as a potential cause specifically as the "logical" weak point, especially once bad telemetry originally indicated the gear door was opened during reentry.)  Hatches in the TPS do require greater attention and maintenance, as well as more actuation to utilize, and include a failure risk, mechanical and thermal, that NASA does not have to accept if it does not want to. Trivializing any addition of risk just does not cut it now. It is another tradeoff to consider.
well, if NASA doesn't like it, SpaceX can just seal up the heatshield and go to splashdown.

Also, Dreamchaser has landing gear which have bigger hatches and CST-100 has airbags so if we're going by portion of the heatshield that has a configuration change, then Dragon V2 wins by miles.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Coastal Ron on 06/01/2014 01:41 am
I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market.

Don't forget Elon's not-so-subtle "single digit millions if volume is high enough" statements.  I don't think he'd be saying that unless he thought there was a chance the volume might actually increase.  And I think we can all agree that NASA is only thinking 4 missions/year max.  So, coupled with Bigelow's presence...

For new markets it helps if you can provide some guidance on what they can expect in the future, and since the cost of flying to space has been prohibitive so far, showing that the price could drop to the singe-digit millions might provide some momentum on the demand side of the market - that companies, individuals and entrepreneurs can start figuring out what they would do if it cost less than $10M to get a human to LEO.

Essentially, with that casual comment Elon Musk just did a TON of marketing for their future crew transportation service.  And he knew he was doing it too...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CJ on 06/01/2014 01:43 am
It's built on the premise of taking many people to and from space, and taking them often.

I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market. So far as I've heard, it's all government space agency customers, all the time. So far as I've heard, NASA remains opposed to private astronauts riding along to the ISS. So far as I've heard, SpaceX isn't interested in space tourism. I have no doubt that at least one of these things I've heard is wrong - I just wish SpaceX would set us straight.

Just my take on this; It was said at the unveil that they'd carry on with Dragon 2 even if they don't get a CCP (and thus no government astronauts). Therefor, they must have some other potential customers in mind? One that comes to my mind is the potential of a manned Dragon Lab for commercial customers. Another is space tourism with SpaceX playing the role of airline rather than resort operator. 

BTW, I'd like to take this opportunity to thank you again for the links and all the transcribing you do.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 01:45 am
the goal is affordable transportation to LEO, and ideally we want that to be a redundant transportation system with at least two providers.

Two providers decreases the chances of a period when transportation is unavailable due to an accident investigation, but it increases the chances of loss of crew.

That's because now instead of a crew being killed if there's a fatal design flaw in one vehicle, a crew will be killed if there's a fatal design flaw in either of two vehicles.

Say, for example, the odds of a fatal design flaw in any given vehicle that isn't caught in testing is 20%, and if there is a fatal design flaw, the odds of it killing a crew on any particular mission is 10%.  With one vehicle, the chance a crew dies is 13%.  With two vehicles, each flying 5 missions, the chance a crew dies is 15.7%.

The exact numbers used don't matter -- spreading the same missions over two different vehicles always gives a higher chance of killing a crew than using the same vehicle for all the missions, unless the one vehicle chosen has a higher chance of a design flaw than the other vehicle -- but in that case, choosing the other vehicle and giving it all the missions reduces the chances of loss of crew.

No two ways about it.  The math is irrefutable.  Using two providers instead of one for commercial crew increases the risk of killing a crew.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 01:56 am
Well we have to remember that Bigelow already quotes prices for using SpaceX to get customers to their private stations (Boeing too), so Bigelow has already done about as much as he can at this point - he's waiting for at least two certified crew transportation systems so that he can start his space station service.

Waiting for NASA to certify two crew transportation systems isn't "about as much as he can at this point".  If he really wanted to, he could sign a contract with one or more crew transport providers.  If there were really a lot of demand for Bigelow's stations, it's hard to believe he would just sit around and wait for NASA, and leave money on the table in the meantime.

If Bob Bigelow were more like Elon Musk maybe he would be more proactive, but I think we're all forgetting how much money this has already cost him and how much more it will take before he starts generating revenue (much less profit).  And without crew transportation he has no business.

So I don't blame Bob Bigelow for not doing more, since besides Elon Musk he has been the most pro-space business person in the world (Branson is only sub-orbital, and no one knows what goals Bezos has for space).

Sure, I agree, we shouldn't blame Bigelow for not pushing ahead faster.

My point was that the fact that he isn't pushing ahead faster indicates he doesn't have a huge number of customers waiting in the wings willing to pay top dollar to use his stations.  We may have to wait for prices to come down quite a bit before Bigelow can financially justify launching an operational station.  How far down they must come only Bigelow knows -- or maybe even he doesn't know.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 02:00 am
Trying to make more of a party here:

Anyone here wonder what Elon might fly on the first Falcon Heavy flight?  I don't remember hearing about a (brave) customer for it, yet, although Elon has hinted that they're still willing to entertain a "last minute" paying customer.  But it doesn't seem SpaceX's style to send up another mass simulator.  Any chance we might see a Dragon v2 with some mouse-tronauts thrown on a lunar free return trajectory?  Or another mars shot?  Given the topic of this thread, let me hear some creative Dragon V2 long shots!

Unfortunately, Dragons aren't free, even for SpaceX.  They have their hands full building Dragons for CRS cargo runs, the two abort tests, an uncrewed orbital test next year, and DragonFly.  I'm not sure they can afford to build yet another Dragon without delaying one of those other programs.  And any of those Dragon V2 test flights (including DragonFly) could fail and leave a smoking crater, in which case SpaceX will need to build another Dragon V2 as quickly as possible to re-start testing.

Then again, if the abort tests go well and the Dragon V2 they used for abort tests is still in good shape, maybe they'll be able to put it on the first Falcon Heavy launch.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 02:02 am
More amazing people excuse making and dismissing of risk. This is how NASA GOT ASTRONAUTS KILLED.  It seems someone learned something from these tragedies, but a lot of folks are still very capable of fooling themselves.  Propulsive landing is difficult, never mind he hatches issue. It involves serious tradeoffs of weight and fuel. Parachutes are lighter and simpler.  if Elon wants a higher risk craft, that is his right. But it is NASA's right to choose something old school and maybe a bit too boring for the armchair enthusiasts who are fixated on the "cool factor" of propulsive landing.

Much as I love to see the huge pile up of amazing people vs hatebois on NSF, when the turbulence throws out unsupported ideas I'm not so endeared. And I'm sure this point has been through reentry before. Oh well:

"Propulsive landing is difficult, never mind he hatches issue. It involves serious tradeoffs of weight and fuel. Parachutes are lighter and simpler."

Put the mass/fuel constraints aside, because that is the optimization that SpaceX drives - and it has made their presumptive tickets to ISS cheaper than the rest, or so they claim.

There are now chute safeties for airplanes. Do they routinely land with them, claiming propulsive landing is difficult? (Which is true BTW, AFAIK it is the most hazardous phase during flight.) No, they balance rapid reuse and cost vs risk. Propulsive landing is simpler and cheaper, for planes/SpaceX rapid reuse.

If NASA would want to minimize risk at every turn, they wouldn't launch astronauts but rely on probes, they wouldn't launch engineers but athletes, they wouldn't test a pizza 3D bakery for ISS but a green salad maker, et cetera. Mostly here, NASA seems to set the rules for CC to ISS, and the craft can do several landing types from chutes in sea to VL on land. If so, it is up to NASA to choose the ticket prize vs mission profile.

Other customers have to play by SpaceX's rules, or negotiate other landing options at a higher prize at a guess.

By the way, Soyuz, the most reliable manned craft in history (?), do propulsive assist landing.

According to the quoted analysis, they do something wrong and they do that error only because of a "cool" factor.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 06/01/2014 02:02 am
I wasn't trying to contradict you, just pointing out that unless something has changed, SpaceX and Bigelow already publicly announced they intend to use the Dragon.  I don't understand why it matters if they are "international customers," sorry if I'm being dense.

That means: other government space agencies.

There was also a press release of an agreement between SpaceX and Space Adventures.. but good luck even finding that. It's like it never happened.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 02:07 am
I would like to say "wrong, see above". But that is likely a loosing proposition.  :o

Wrong again. It's a losing proposition

So it is, especially since it was played fast and loose. But it is still likely losing.

"What would a nitpicker pick, if a nitpicker not picked nits?"  ???
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 06/01/2014 02:10 am
The inherent weaknesses of the shuttle systems are exactly why we are havin this debate at all.  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.if there is a newfound emphasis on safety and simplicity/ reliability,specifically in the wake of a catastrophic burnthrough, this should not be a surprise. It is added risk.

The "catastrophic burnthrough" on Columbia had nothing to do with hatches in its heat shield, and everything to do with design details that Falcon 9 and Dragon do not share.  Your argument relies on irrelevancies.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 06/01/2014 02:14 am
There are now chute safeties for airplanes. Do they routinely land with them, claiming propulsive landing is difficult?

Planes don't land propulsively.

Quote
By the way, Soyuz, the most reliable manned craft in history (?), do propulsive assist landing.

That's an almost all-chute landing, with the propulsive assist in the last fraction of a second.  That's entirely different.  SpaceX isn't planning to deploy chutes at all, just carry them to orbit and back.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 02:18 am
There was also a press release of an agreement between SpaceX and Space Adventures.. but good luck even finding that. It's like it never happened.

Probably because it never happened. Space Adventures partnered with Boeing

http://spaceflightnow.com/news/n1009/15boeingtourism/
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 02:26 am
the goal is affordable transportation to LEO, and ideally we want that to be a redundant transportation system with at least two providers.

Two providers decreases the chances of a period when transportation is unavailable due to an accident investigation, but it increases the chances of loss of crew.

That's because now instead of a crew being killed if there's a fatal design flaw in one vehicle, a crew will be killed if there's a fatal design flaw in either of two vehicles.

Say, for example, the odds of a fatal design flaw in any given vehicle that isn't caught in testing is 20%, and if there is a fatal design flaw, the odds of it killing a crew on any particular mission is 10%.  With one vehicle, the chance a crew dies is 13%.  With two vehicles, each flying 5 missions, the chance a crew dies is 15.7%.

The exact numbers used don't matter -- spreading the same missions over two different vehicles always gives a higher chance of killing a crew than using the same vehicle for all the missions, unless the one vehicle chosen has a higher chance of a design flaw than the other vehicle -- but in that case, chosing the other vehicle and giving it all the missions reduces the chances of loss of crew.

No two ways about it.  The math is irrefutable.  Using two providers instead of one for commercial crew increases the risk of killing a crew.

"Irrefutable"? Only if you assume some sort of risk "statics" instead of dynamics. Say, if competition does not decrease risks. As it does in car industry, for example.

Oh, and it is "choosing". [/nitpick joke revenge mode]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 06/01/2014 02:27 am
And that isn't the mission either. You've reduced the whole thing to nothing more than a PR exercise.

At the end of the day, the funding happens because there is public and congressional support for it.
In my opinion, Elon Musk and his crew have a lot better chance of building public support and NASA funding via their exciting strategy.

CST-100 and Dream Chaser don't seem to inspire anyone to care except the contractors getting the paychecks.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 06/01/2014 02:30 am
There was also a press release of an agreement between SpaceX and Space Adventures.. but good luck even finding that. It's like it never happened.

Probably because it never happened. Space Adventures partnered with Boeing

http://spaceflightnow.com/news/n1009/15boeingtourism/

It was before that. But yes, that says a lot about how interested SpaceX is in non-government customers for human spaceflight right now.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 02:33 am
the goal is affordable transportation to LEO, and ideally we want that to be a redundant transportation system with at least two providers.

Two providers decreases the chances of a period when transportation is unavailable due to an accident investigation, but it increases the chances of loss of crew.

That's because now instead of a crew being killed if there's a fatal design flaw in one vehicle, a crew will be killed if there's a fatal design flaw in either of two vehicles.

Say, for example, the odds of a fatal design flaw in any given vehicle that isn't caught in testing is 20%, and if there is a fatal design flaw, the odds of it killing a crew on any particular mission is 10%.  With one vehicle, the chance a crew dies is 13%.  With two vehicles, each flying 5 missions, the chance a crew dies is 15.7%.

The exact numbers used don't matter -- spreading the same missions over two different vehicles always gives a higher chance of killing a crew than using the same vehicle for all the missions, unless the one vehicle chosen has a higher chance of a design flaw than the other vehicle -- but in that case, chosing the other vehicle and giving it all the missions reduces the chances of loss of crew.

No two ways about it.  The math is irrefutable.  Using two providers instead of one for commercial crew increases the risk of killing a crew.

"Irrefutable"? Only if you assume some sort of risk "statics" instead of dynamics. Say, if competition does not decrease risks. As it does in car industry, for example.

Right, it's possible for competition to lower risks.  So CCDev 1, CCDev 2, and CCiCap might have lowered the risks.  But now that the designs are all at an advanced state, it's hard to see how choosing two instead of one for CCtCap will lower risks more.

Oh, and it is "choosing". [/nitpick joke revenge mode]

Thanks, fixed!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 02:35 am
CST-100 and Dream Chaser don't seem to inspire anyone to care except the contractors getting the paychecks.

Judging by this forum, Dream Chaser also seems to inspire a lot of people.  Personally, Dragon inspires me a whole lot more, but Dream Chaser definitely has its passionate fans.

CST-100 doesn't seem to inspire the same passion.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 02:38 am
There are now chute safeties for airplanes. Do they routinely land with them, claiming propulsive landing is difficult?

Planes don't land propulsively.


References, please.  :P

More seriously, are we having some interpretation issues? Only gliders don't land using engines.

Quote
By the way, Soyuz, the most reliable manned craft in history (?), do propulsive assist landing.

That's an almost all-chute landing, with the propulsive assist in the last fraction of a second.  That's entirely different.  SpaceX isn't planning to deploy chutes at all, just carry them to orbit and back.

I think I laid out the options in that comment, who are more than you claim and outside of SpaceX plans for non-regulated use. More specifically, you are cherry picking. I was commenting on the unsubstantiated claims around "Propulsive landing is difficult [which I noted it is, but the point is that it is used] ... the "cool factor" of propulsive landing."
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/01/2014 02:43 am
And that isn't the mission either. You've reduced the whole thing to nothing more than a PR exercise.

At the end of the day, the funding happens because there is public and congressional support for it.
In my opinion, Elon Musk and his crew have a lot better chance of building public support and NASA funding via their exciting strategy.

CST-100 and Dream Chaser don't seem to inspire anyone to care except the contractors getting the paychecks.

Not true.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ncb1397 on 06/01/2014 02:46 am
By the way, Soyuz, the most reliable manned craft in history (?), do propulsive assist landing.

Soyuz had a decompression event killing 3 cosmonauts and a parachute failure killing 1 lone cosmonaut over 122 missions and multiple generations. Space Shuttle had a heat shield fail and a booster fail killing 2 crews. Apollo fire killed 3 astronauts on the pad with 12 manned missions. Shenzou has had no fatalities over 5 missions.

Loss of crew event:
Soyuz:1.6%
Shenzou: 0%
Apollo: 8.3%
Shuttle:1.5%
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 02:46 am
Planes don't land propulsively.

More seriously, are we having some interpretation issues? Only gliders don't land using engines.

Rather than getting bogged down over what exactly "propulsive" means, let's get to the point.  The point, I think, is that airplanes don't automatically crash if they lose propulsion during their landing approach.  They can potentially glide to a safe landing.  However, it's also true that if a plane loses all propulsion on its final approach there is a significant danger it will crash, and many planes have crashed in exactly that situation.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DMeader on 06/01/2014 02:51 am
References, please.  :P
More seriously, are we having some interpretation issues?

Suffice it to say that all of your examples are either comparing apples and oranges (aircraft landing vs. propulsive spacecraft landing) or simply wrong... Soyuz is not propulsive landing, only some solids fired at the last moment to cushion the impact.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 02:53 am
There was also a press release of an agreement between SpaceX and Space Adventures.. but good luck even finding that. It's like it never happened.

Probably because it never happened. Space Adventures partnered with Boeing

http://spaceflightnow.com/news/n1009/15boeingtourism/

It was before that. But yes, that says a lot about how interested SpaceX is in non-government customers for human spaceflight right now.


All the press releases of both Space Adventures and SpaceX are archived on multiple websites, including their own. There is not a single PR piece that links them together in any agreement or partnership. And something like that would have been widely reported by blogs everywhere too.
In 2008/2009 SA was actively talking about Soyuz flights, and in 2010 they made the Boeing announcement.

Please don't tell us there is a vast conspiracy going on here.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 02:56 am
So... If NASA doesn't like it or if it proves unreliable, they go to splashdown like they do now.

What are we still arguing about? Do you guys think that both NASA* and SpaceX are so reckless that they're flying by the seat of their pants and just are doing things "for show" and a bunch of random people on the Internet know so much better?



*NASA is the customer, so they WILL tell SpaceX if propulsive landing is out of the question (and SpaceX will listen). SpaceX merely has to go to splashdown or hybrid land-landing (i.e. parachutes with last-second SuperDraco cushion), which shouldn't be a problem. Heck for all we know, the plan is STILL to start out early flights with splashdown and/or hybrid parachute/landing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 02:59 am
There are now chute safeties for airplanes. Do they routinely land with them, claiming propulsive landing is difficult?

Planes don't land propulsively.

References, please.  :P

Harriers, V-22s and all sorts of helicopters land ( and sometimes, crash ) "propulsively" all the time.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 03:02 am
So... If NASA doesn't like it or if it proves unreliable, they go to splashdown like they do now.

What are we still arguing about? Do you guys think that both NASA* and SpaceX are so reckless that they're flying by the seat of their pants and just are doing things "for show" and a bunch of random people on the Internet know so much better?

*NASA is the customer, so they WILL tell SpaceX if propulsive landing is out of the question. SpaceX merely has to go to splashdown or hybrid land-landing (i.e. parachutes with last-second SuperDraco cushion), which shouldn't be a problem. Heck for all we know, the plan is STILL to start out early flights with splashdown and/or hybrid parachute/landing.

Yeah, and to take that logic even further, if NASA really wasn't sold on propulsive landing, they would already have told SpaceX about it.  Just look at all the review milestones SpaceX has passed in its CCiCap contract with NASA.  Each of those review milestones involves SpaceX doing presentations for lots of NASA people.  All of those NASA people get to ask questions and have to be satisfied with all the answers before SpaceX is paid for the milestone.  SpaceX has passed a number of such review milestones, so all those NASA people have signed off on the Dragon V2 plans.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 03:25 am
Seriously, everyone hyperventilating about the dangers of "propulsive landings", look into helicopters some time. And entire debates and myths between pilots of piston vs turbine engines and so on. People even climb into homebuilt famously unreliable helis like Mini-500 every day. ( EDIT: reading this again, thats an exaggeration. The venn diagram of still existing Mini-500s and number of suicidal maniacs in the world gives a lower frequency )

And then think about the reliability of a single reciprocating piston engine with hundreds of moving parts that has maybe been maintained sort of according to what manufacturer thinks is about right ( but sometimes the tech is a drunk or has family problems ).
Versus a number of hypergolic engines with almost no moving parts, a type of engine that usually still reliably ignites after decades of cruising through deep space. And then you have a parachute backup.

EDIT: I'll just leave this quote from wikipedia here http://en.wikipedia.org/wiki/Revolution_Mini-500#Rotax_582
Quote
"This engine, by its design, is subject to sudden stoppage. Engine stoppage can result in crash landings, forced landings or no power landings. Such crash landings can lead to serious bodily injury or death ... This is not a certificated aircraft engine. It has not received any safety or durability testing, and conforms to no aircraft standards. It is for use in experimental, uncertificated aircraft and vehicles only in which an engine failure will not compromise safety. User assumes all risk of use, and acknowledges by his use that he knows this engine is subject to sudden stoppage ...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DMeader on 06/01/2014 03:33 am
Seriously, everyone hyperventilating about the dangers of "propulsive landings"...

The point is that this puts the concept into quite a new regime. It has never been done with a manned vehicle of this type, and it needs to be properly vetted, tested and proven, not just "oh, Elon, cool let's go!".
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 06/01/2014 03:41 am
Which is what DragonFly and the abort tests are about, and NASA is watching. If NASA gives it a pass I suggest the hyperventilators find a paper bag, put its open end over their mouth and breathe deeply.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 03:45 am
Seriously, everyone hyperventilating about the dangers of "propulsive landings"...

The point is that this puts the concept into quite a new regime. It has never been done with a manned vehicle of this type, and it needs to be properly vetted, tested and proven, not just "oh, Elon, cool let's go!".

I trust that thousands of people with aerospace skills and backgrounds that are involved in this program from both SpaceX and NASA side are getting paid to do just that, properly vet, test and prove this thing. Given the amount of oversight involved, i guess it will end up doing better at landings than your average Robinson R22, assuming it will ever rack up meaningful number of flights and crashes to compare.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/01/2014 03:54 am
If today a down select were forced by congress to a single provider the choice would go to CST100(Orion) because that program has the political momentum to sustain it.

Except that CST-100 and Orion are totally different capsules being built by different companies.
Thanks for pointing that out. My point is that the political momentum favors LM/Boeing.
As we were reminded by the House Space Subcommittee recently, by law Orion is the backup ISS transport system -if for example the commercial crew program were cancelled next year.
The politicians that support SLS/Orion on the house space subcommittee and Shelby in the Senate will support the business interests in their districts; LM/Boeing. They will not bite the hand that feeds them and would be inclined to select CST100 if CCP isn't killed outright.
These gentlemen have been underfunding CCP while stating they want a 70% assurance level of funding for SLS/Orion.  Technical merit and science have nothing to do with politics, else we would see funding for the climate research satellites that were cancelled or funding for SLS payload development.
The end of ISS in 2020 will allow for a very strong argument that there is no need to spend 3.4b on CCP for 4-6 launches.
But I believe as SpaceX captures the worlds commercial satellite launch market the SpaceX R&D party will go on regardless of what congress does to NASA CCP and ISS funding past 2020 in order to support their Precious.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 03:59 am
Technical merit does matter. NASA needs a program that actually flies people, so they will push for whoever is technically meritorious. Politics is not the ONLY consideration, or else we wouldn't even be having this discussion because Boeing and LM would've long figured out how to funnel money directly to shareholders instead of building cool spacecraft and the like.

Besides, SpaceX is starting to get some pull on Capital Hill these days.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ThereIWas3 on 06/01/2014 04:01 am
And then think about the reliability of a single reciprocating piston engine with hundreds of moving parts that has maybe been maintained sort of according to what manufacturer thinks is about right ( but sometimes the tech is a drunk or has family problems ).

I know a guy who flies a Beechcraft Bonanza.  Once he took it in for maintenance to one of those very highly paid
licensed aircraft mechanics.  Who forgot to tighten all the bolts on the oil pump when he was done.  The owner shows
up, starts the engine, and taxis out to the runway.   A frantic call on the radio tells him he is spreading oil all over the place.
He shuts the engine down - luckily had not started takeoff - but not quite soon enough to prevent damage.   The owner
of the repair facility had to buy him a new engine, which costs several tens of thousands of dollars.

Two kinds of people use checklists all the time: beginners, and experienced professionals.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 04:05 am
If today a down select were forced by congress to a single provider the choice would go to CST100(Orion) because that program has the political momentum to sustain it.

Except that CST-100 and Orion are totally different capsules being built by different companies.
Thanks for pointing that out. My point is that the political momentum favors LM/Boeing.
As we were reminded by the House Space Subcommittee recently, by law Orion is the backup ISS transport system -if for example the commercial crew program were cancelled next year.
The politicians that support SLS/Orion on the house space subcommittee and Shelby in the Senate will support the business interests in their districts; LM/Boeing. They will not bite the hand that feeds them and would be inclined to select CST100 if CCP isn't killed outright.
These gentlemen have been underfunding CCP while stating they want a 70% assurance level of funding for SLS/Orion.  Technical merit and science have nothing to do with politics, else we would see funding for the climate research satellites that were cancelled or funding for SLS payload development.
The end of ISS in 2020 will allow for a very strong argument that there is no need to spend 3.4b on CCP for 4-6 launches.
But I believe as SpaceX captures the worlds commercial satellite launch market the SpaceX R&D party will go on regardless of what congress does to NASA CCP and ISS funding past 2020 in order to support their Precious.

If Congress were making the decision about which company or companies to select for CCtCap, I would agree with you, it would be about politics more than technical merit.

But Congress is not making this decision.  NASA is.  The NASA people making this decision have no voters to keep happy or campaign financing to win.  I think it highly likely NASA will make the decision on the technical merits of the proposals.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ronpur50 on 06/01/2014 04:10 am
Well, I have to say, propulsive landing will make me nervous watching, just hoping the engines stay on until touchdown.

But I was also nervous on every single shuttle landing, just hoping the landing gear would drop before the orbiter smacked the runway.

But I was also nervous on every single Apollo splashdown, hoping to see 3 good parachutes inflate before the capsule smacked the ocean. (Thanks for the heart palpitations, Apollo 15!)

I don't think this business will ever be safe.  We just have to design redundancies and test.  Then test and test some more.  And practice practice and practice.  Then it will just be a little less dangerous, but never safe.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 04:15 am
I know a guy who flies a Beechcraft Bonanza.  Once he took it in for maintenance to one of those very highly paid
licensed aircraft mechanics.  Who forgot to tighten all the bolts on the oil pump when he was done..

Yep, there is any number of stories like these in civil aviation. A dual engine Eurocopter recently came down in Glasgow, after apparently BOTH engines flamed out. It crashed into a pub killing about dozen people.

Again, I don't see a lot of technical reasons why this type of propulsive landing with parachute backup would not work out to be at least slightly more reliable than helicopters.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Oli on 06/01/2014 04:18 am
There are now chute safeties for airplanes. Do they routinely land with them, claiming propulsive landing is difficult?

Planes don't land propulsively.

References, please.  :P

Harriers, V-22s and all sorts of helicopters land ( and sometimes, crash ) "propulsively" all the time.

Its not so much propulsive landing per se, altough helis are less safe than planes, but the fact that the capsule comes down at high speed with little fuel so you have only a short time window to put it down accurately and softly. There is little margin for error.

But its doable I guess.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 04:23 am
Well, I have to say, propulsive landing will make me nervous watching, just hoping the engines stay on until touchdown.

And I think that's what's really at the heart of the aversion to propulsive landing.  Our intuition tells us it's a bad idea to rely on a device to keep actively running to keep someone from dying.

But our intuition can be wrong.  It's based on lumping Superdraco engines into the same category of all sorts of machines we've experienced problems with in our lives.  We just don't trust machines because we think of them as things that can unexpectedly fail.

This isn't logical.  There's no fundamental reason that a particular machine can't be extremely reliable.  As others have pointed out, hypergolic engines are extremely simple and have proven very reliable.  In the case of Dragon V2, the engines will be tested at a few thousand feet, and if there is a failure, parachutes will be used instead.  And then even if an engine fails later, it can still land safely because there are 8 engines.

There may be some bugs that are found in testing that need to be fixed, but I'm confident that over time propulsive landing of Dragon V2 will turn out to be extremely safe.  Far safer than a parachute landing.  Probably also safer than a glider landing, where a sudden change in winds and no engine to do a go-around can lead to disaster.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 04:23 am
Its not so much propulsive landing per se, altough helis are less safe than planes, but the fact that the capsule comes down at high speed with little fuel and you have only a short time window to put it down accurately and softly. There is little margin for error.
But its doable I guess.

I'm a recreational skydiver and i am pretty used to falling out of the sky with absolutely no fuel and a short time window to act when something goes wrong. Lots of people enjoy this fine activity with no greater purpose than the hell of it around the world.

However, some peple ( people on this forum, too )  jump off bridges and towers with just one parachute which leaves you absolutely zero margin for error - i think that's just batshit insane.

Oh, and i also get nervous in helicopters. "Safety" is relative. Reliability can be designed in, built and proven.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Comga on 06/01/2014 04:32 am
Interesting comparison
When was that old version first shown?  Not all that long ago, IIRC
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sanman on 06/01/2014 04:33 am
How stable is propulsive landing likely to be in the face of wind sheer and other atmospheric turbulence phenomena?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/01/2014 04:39 am
How stable is propulsive landing likely to be in the face of wind sheer and other atmospheric turbulence phenomena?

Pretty darn good.  You're already balancing a broom by its end -- a little bit of extra wind is nothing.

You might want to look up some of the old Armadillo Aerospace clips.  There was one where Pixel was tested in a fierce wind.  Didn't bother it a bit, but you could see everything around it being blown and the vapor trail was near-horizontal.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RocketGoBoom on 06/01/2014 04:42 am
Seriously, everyone hyperventilating about the dangers of "propulsive landings"...

The point is that this puts the concept into quite a new regime. It has never been done with a manned vehicle of this type, and it needs to be properly vetted, tested and proven, not just "oh, Elon, cool let's go!".

I am sure there will be quite a few unmanned landings with the Super Dracos before they do it with anyone on board.
Once we have seen it happen 10+ times unmanned from various altitudes, then everyone will have a lot more confidence in this method.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/01/2014 04:45 am
There was also a press release of an agreement between SpaceX and Space Adventures.. but good luck even finding that. It's like it never happened.

Probably because it never happened. Space Adventures partnered with Boeing

http://spaceflightnow.com/news/n1009/15boeingtourism/

It was before that. But yes, that says a lot about how interested SpaceX is in non-government customers for human spaceflight right now.

Yes and no...

SA specializes in "space tourism" under a very limited government controlled scenario.  SpaceX might have figured that in a private-only world (think Dragon orbital, or Dragon-round-the-moon), SA will not have much of an edge over other players.

Plus, SpaceX might have figured that after seeing the costs of the combined Dragon/F9 vs. CST/Atlas, SA will come back...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/01/2014 04:50 am
There are now chute safeties for airplanes. Do they routinely land with them, claiming propulsive landing is difficult?

Planes don't land propulsively.

References, please.  :P

Harriers, V-22s and all sorts of helicopters land ( and sometimes, crash ) "propulsively" all the time.

Its not so much propulsive landing per se, altough helis are less safe than planes, but the fact that the capsule comes down at high speed with little fuel so you have only a short time window to put it down accurately and softly. There is little margin for error.

But its doable I guess.

The timing is an illusion.  What if the air-brake on the shuttle, or one of the control surfaces, failed during reentry?  It won't be "a second before the crash", but it will be just as fatal.

With a winged lander, once it is on final approach and can flare, you know it won't be a bad day - but it's just that the "one shot drama" has already been played out.

So basically, with a winged lander, if you're going to get killed, you will know it for a longer amount of time - that's about all.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/01/2014 05:22 am

If Congress were making the decision about which company or companies to select for CCtCap, I would agree with you, it would be about politics more than technical merit.

But Congress is not making this decision.  NASA is.  The NASA people making this decision have no voters to keep happy or campaign financing to win.  I think it highly likely NASA will make the decision on the technical merits of the proposals.
Congress makes the decisions which NASA programs to fund, not NASA, and congress can enact laws to see that preferred programs such as SLS/Orion are carried out -hence a launch system with no funded payload R&D.
No long term destination in LEO -ISS past 2020, no need to support the short term development funding getting us there.
Again, I'd like to point out the cancelled climate science missions as to how special interests shape the research that agencies such as NOAA and NASA are allowed to facilitate.
No bucks, no B...err no CCP.
In spite of potential roadblocks, I believe SpaceX will persevere and flourish. Re-usability is a game changer.
Instead of funneling money to dividends for shareholders, SpaceX is investing in R&D that if successful will crush world launch market competition; the very powerful old guard which is presently rooted in a single use paradigm.
They will do everything they can to slow the research funding for the newcomer while they stumble to catch up.
w/r to the propulsive landing naysayers;
We never crashed a LEM and that Curiosity sky crane thing was pretty cool, how many engines did it have?
So my hat is off to the man, the lead designer, who gives the resources to engineers to solve the difficult problems.
Party on Elon.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 05:36 am

If Congress were making the decision about which company or companies to select for CCtCap, I would agree with you, it would be about politics more than technical merit.

But Congress is not making this decision.  NASA is.  The NASA people making this decision have no voters to keep happy or campaign financing to win.  I think it highly likely NASA will make the decision on the technical merits of the proposals.
Congress makes the decisions which NASA programs to fund, not NASA, and congress can enact laws to see that preferred programs such as SLS/Orion are carried out -hence a launch system with no funded payload R&D.

Yes, Congressional protectors of the status quo could kill CCtCap funding for future years.  But they've been trying for years to kill all commercial crew funding, and they've failed.  They've reduced the funding levels, but failed to kill it.  They tried to avoid aving CCtCap at all.  They failed.  It's too late for them to keep CCtCap from being awarded, and it's too late for them to keep it from being a fair and open competition.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Manabu on 06/01/2014 06:06 am
I like this idea of powered landing, having the chutes as fallback. Now I want to better understand the engine out capability of Dragon V2.

Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?

If eight engines can accelerate at 6G for LAS, so four engines could decelerate the craft at about 3G (plus air resistance). That seems like good rate, but there is the fuel problem too. Will it carry two times more fuel than necessary? What is Dragon V2 delta-v?

Now, I'm assuming that by "land safely" he means a perfect soft landing. So here comes another question: how bad those systems can malfunction before someone dies? Can we have almost complete failure and the crew still survive, although injured and with the craft destroyed? Some really bad scenarios:
- No chute, only two engines, capable of 1.5G (?) of deceleration (plus air resistance).
- No engine (they work the first test fire, but not afterwards) and late chute release?
- Entangled chute, no engine (Soyuz 5 like)?
- Total failure, falls like a rock hitting the surface at terminal velocity.

In all those scenarios, we would have the landing legs (ok, they may malfunction too), seats and the craft body absorbing the impact of lithobreaking. But I guess those things are designed to be light, not for absorbing high speed impact, right? Would make a difference if it lands on the water or snow?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 06:23 am
I like this idea of powered landing, having the chutes as fallback. Now I want to better understand the engine out capability of Dragon V2.

Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?

If eight engines can accelerate at 6G for LAS, so four engines could decelerate the craft at about 3G (plus air resistance). That seems like good rate, but there is the fuel problem too. Will it carry two times more fuel than necessary? What is Dragon V2 delta-v?

Now, I'm assuming that by "land safely" he means a perfect soft landing. So here comes another question: how bad those systems can malfunction before someone dies? Can we have almost complete failure and the crew still survive, although injured and with the craft destroyed? Some really bad scenarios:
- No chute, only two engines, capable of 1.5G (?) of deceleration (plus air resistance).
- No engine (they work the first test fire, but not afterwards) and late chute release?
- Entangled chute, no engine (Soyuz 5 like)?
- Total failure, falls like a rock hitting the surface at terminal velocity.

In all those scenarios, we would have the landing legs (ok, they may malfunction too), seats and the craft body absorbing the impact of lithobreaking. But I guess those things are designed to be light, not for absorbing high speed impact, right? Would make a difference if it lands on the water or snow?

Those are very good questions.

I also wondered what exactly Musk meant about engine-out capability.  He wasn't really clear on whether he meant any two engines can fail or two engines can fail if it's the right two engines.

Since there are four independent propellant systems for eight engines, each tank must feed two engines.  As someone else pointed out in another post, they probably arranged it so the pair of engines a single tank feeds are on opposite sides, so a failure of that tank will have the least bad effect on the craft.  So maybe that's what Musk meant, that a propellent system failure can take out a pair of linked engines on opposite sides and the craft can still land safely.

As you point out, if two engines in a pair that share a mount fail, it seems like it would be hard to land it successfully unless they carry a lot of spare propellent.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/01/2014 06:39 am

If Congress were making the decision about which company or companies to select for CCtCap, I would agree with you, it would be about politics more than technical merit.

But Congress is not making this decision.  NASA is.  The NASA people making this decision have no voters to keep happy or campaign financing to win.  I think it highly likely NASA will make the decision on the technical merits of the proposals.
Congress makes the decisions which NASA programs to fund, not NASA, and congress can enact laws to see that preferred programs such as SLS/Orion are carried out -hence a launch system with no funded payload R&D.

Yes, Congressional protectors of the status quo could kill CCtCap funding for future years.  But they've been trying for years to kill all commercial crew funding, and they've failed.  They've reduced the funding levels, but failed to kill it.  They tried to avoid aving CCtCap at all.  They failed.  It's too late for them to keep CCtCap from being awarded, and it's too late for them to keep it from being a fair and open competition.
They've been trying for years to kill the commercial crew program without a valid excuse because NASA planned for the ISS to be operational beyond 2024.
If the ISS is going away in 2020, why fund 3.4b in technology development that will only have a viable purpose for two or three years? I can see that 3.4 billion diverted directly to an accelerated Orion program or to increase funding for the Justice department.
The primary domestic launch providers, LM, Boeing, ULA are dependent on USG profits for survival and don't compete well in the world commercial launch market
It really is SpaceX v. The World.
France and Russia are as concerned about losing the commercial launch market to SpaceX as the traditional US launch providers are about losing EELV business.
Quote from: Spacenews
In a briefing with journalists, Fioraso said France nonetheless has issues with extending its participation to 2024 without an indication from NASA that its support for rocket builder Space Exploration Technologies Corp. will not permit SpaceX to proceed with “dumping, because that’s what it is,” of cheap SpaceX rockets on the international market where they compete with Europe’s Ariane 5 vehicle.
http://www.spacenews.com/article/civil-space/40669orion%E2%80%99s-european-service-module-back-on-track (http://www.spacenews.com/article/civil-space/40669orion%E2%80%99s-european-service-module-back-on-track)
If splashing the ISS in 2020 will help to slow down the upstart then so be it.
In the US we don't need no stinkin' CCP because by law we have Orion as the ISS backup provider.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 06/01/2014 07:20 am
Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?
I was thinking about that and I think you don't actually need to completely turn the opposite cluster off, because their arrangement is not symmetrical. Anyone up for a simulation?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 06/01/2014 07:47 am
From the LIVE thread:

Has anyone noticed how the super-dracos angle is much steeper than previously thought.

Less than half the 45 degrees from vertical the first CGIs showed.

That will reduce thrust cosine losses from 29% to just 7%.

Not bad.

We can calculate backwards from performance numbers.

8 x 16400 is the maximum performance of the superdracos.

It will be run at sligthly lower pressure/thrust (at least initially) to be conservative about margins for reliability and reuse. I saw/heard the number somewhere -- it was 15XXX -- pity I do not remember the last digits. Does someone else remember derated thrust number for superdraco and where it came from?

If the 120000 axial trust figure is based on max performance, the efficiency after cosine losses is 91.5% (8.5%loss) and the angle about 24 degrees. If it is based on the slightly de-rated flight numbers, the efficiency will be better and the angle smaller. So I think we can at least say that the angle is not more than 24 degrees.

120000 for axial trust (and 16000 from the presentation) are rounded off numbers -- So the numbers will be approximate.

Have anyone found more accurate thrust numbers that are known whether they are max performance or flight performance? (We can move this to L2 if the numbers are not public)

I am not really an expert on this (just an engineer in a different field) so feel free to correct if I have made any mistakes in my calculations.

edit: Some additional points:

- I forgot about the difference between vacuum and sea level performance -- blushing in shame now for such a rookie mistake. I think the max performance number (16400lbf) is vacuum thrust. Another variable to add. Thrust isnt just an unqualified number -- it depends on ambient pressure, de-rating and maybe other stuff. Well it's rocket science after all.

- I am not 100% sure about the de-rating. I think that is what I heard/saw, but it might have been a misunderstanding, and it could for example have been the sea-level thrust I saw/heard.

- There is a number of 15000lbf floating around for superdraco thrust in news articles, but that is just a misunderstanding from journalists not knowledgeable enough to know about cosine losses. Its just the dragon axial thrust number (~120000) divided by 8.

UPDATE: Took the discussion to the superdraco thread (http://forum.nasaspaceflight.com/index.php?topic=29855.msg1207918#msg1207918) and got some of the answers. Here was not the best place anyway, and this thread was MUCH too noisy today and my answer was drowned out by a deluge of mostly subjective opinions flying left and right about Dragon V2 reliabilty and similarly non-objective things.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 08:08 am
Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?
I was thinking about that and I think you don't actually need to completely turn the opposite cluster off, because their arrangement is not symmetrical. Anyone up for a simulation?

Huh?  Each cluster of two engines is exactly symmetrical to another cluster of two engines.  If you lose one cluster entirely, and the two clusters to the left and right of it are still firing at full thrust, you have to have the cluster opposite the lost cluster entirely off to avoid asymmetric thrust flipping the capsule end-over-end.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 06/01/2014 08:15 am
The biggest problem I have with Dragon-2 isn't in any way with its technology or design. My concern is that it is simply too big a leap forward from Dragon-1 to be available for operational use in a timely manner. The whole point in having the crew and cargo Dragon as variants of the same basic spacecraft was to accelerate the development process. Dragon-2 just has too many upgrades and modifications and this can only slow the process.

At the risk of sounding a defeatist, if SpaceX insists on making Dragon-2 its commercial crew product to NASA for the 2016-20 ISS missions, then I'm not convinced it will have flown with a crew before the end of CY2016.

My hope at this point is that the Dragon-2 rollout has nothing to do with commercial crew and is a product that SpaceX are developing aside from their NASA interests for later introduction into the market. If they push ahead with a Crewed Dragon-1 (call it v.1.1, if you like) for NASA and then let Dragon-2 have an unhurried dev process like the reusable Falcon-9 core, then you have the best of both worlds.


[edit]
Fixed typo
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 08:30 am
The biggest problem I have with Dragon-2 isn't in any way with its technology or design. My concern is that it is simply too big a leap forward from Dragon-1 to be available for operational use in a timely manner. The whole point in having the crew and cargo Dragon as variants of the same basic spacecraft was to accelerate the development process. Dragon-2 just has too many upgrades and modifications and this can only slow the process.

Slow compared to a hypothetical alternative that is more similar to Dragon 1 or slow compared to Dream Chaser and CST-100?  If you mean the former, I agree, but if you mean the latter I disagree.  And the latter is all that matters to the CCtCap competition.  Dream Chaser and CST-100 were starting from even less, and they are less far along today than Dragon 2.

At the risk of sounding a defeatist, if SpaceX insists on making Dragon-2 its commercial crew product to NASA for the 2016-20 ISS missions, then I'm not convinced it will have flown with a crew before the end of CY2016.

Well, there's always a chance it will slip, but I think the chances of a crewed flight in 2016 are quite high.  Why do you think it's so unlikely?  They're far enough along that they've completed acceptance testing of the SuperDraco engines, they have pad abort and max-Q abort tests planned in the next 12 months, they have DragonFly tests planned in the next 12 months, they've already completed parachute drop tests, and they've already built the unit that they plan to fly to orbit on the first uncrewed flight.  That seems pretty far along to me, and on track for a crewed flight in 2016.

My hope at this point is that the Dragon-2 rollout has nothing to do with commercial crew and is a product that SpaceX are developing aside from their NASA interests for later introduction into the market. If they push ahead with a Crewed Dragon-1 (call it v.1.1, if you like) for NASA and then let Dragon-2 have an unhurried dev process like the reusable Falcon-9 core, then you have the best of both worlds.

I think they've been pretty clear that Dragon 2 is their CCDev/CCiCap/CCtCap vehicle.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: IRobot on 06/01/2014 09:03 am
Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?
I was thinking about that and I think you don't actually need to completely turn the opposite cluster off, because their arrangement is not symmetrical. Anyone up for a simulation?

Huh?  Each cluster of two engines is exactly symmetrical to another cluster of two engines.  If you lose one cluster entirely, and the two clusters to the left and right of it are still firing at full thrust, you have to have the cluster opposite the lost cluster entirely off to avoid asymmetric thrust flipping the capsule end-over-end.
Each pair of cluster is symmetrical, but the 2 pairs are not. Also each cluster has actually some distance between nozzles, I wonder if there is something that can be squeezed from fine balancing the thrust of each engine, without simply shutting down the opposite engines.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 09:17 am
Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?
I was thinking about that and I think you don't actually need to completely turn the opposite cluster off, because their arrangement is not symmetrical. Anyone up for a simulation?

Huh?  Each cluster of two engines is exactly symmetrical to another cluster of two engines.  If you lose one cluster entirely, and the two clusters to the left and right of it are still firing at full thrust, you have to have the cluster opposite the lost cluster entirely off to avoid asymmetric thrust flipping the capsule end-over-end.
Each pair of cluster is symmetrical, but the 2 pairs are not. Also each cluster has actually some distance between nozzles, I wonder if there is something that can be squeezed from fine balancing the thrust of each engine, without simply shutting down the opposite engines.

OK, so assume you lose one cluster.  Call that Cluster A.  Call the opposite cluster Cluster C.  Call the other two clusters B and D.

If B and D are firing at full throttle, what happens, when you turn on C even a little?  Its true that you can compensate for a small amount of thrust from C by adjusting the thrust of the two engines in each of B and D.  The problem is that you need to balance the thrust from C through the plane that cuts through B and D.  So by reducing the thrust on the engine of B closer to C and the engine of D closer to C, you can balance the thrust again and have the vessel stay level.

But how much do you have to cut the thrust of those two engines in B and D?  The answer is by a lot more than the thrust of C.  That's because the engines in B and D are much closer to the plane that you need to balance around.  So C has a much larger arm.  The net result is much less overall thrust if you turn on C a bit and have to reduce some thrust in B and D.

If you lose A, the maximum overall thrust you can get while still keeping the craft upright is to entirely turn off C and keep the four engines of B and D at maximum throttle.


Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: guckyfan on 06/01/2014 09:26 am
It's built on the premise of taking many people to and from space, and taking them often.

Now that is worth partying about!

I couldn't agree more, but it'd be a lot easier to get the champagne flowing if SpaceX would give us any indication that they were going after that market. So far as I've heard, it's all government space agency customers, all the time. So far as I've heard, NASA remains opposed to private astronauts riding along to the ISS. So far as I've heard, SpaceX isn't interested in space tourism. I have no doubt that at least one of these things I've heard is wrong - I just wish SpaceX would set us straight.

What about NASA setting us straight?

I do remember NASA did an evaluation on a business case outside of NASA and SpaceX Dragon came out far ahead of the competition on this point.

Correct me if I am wrong.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: CuddlyRocket on 06/01/2014 11:09 am
As written by NASA: "The objective of the CCP is to facilitate the development of a U.S. commercial crew space transportation capability with the goal of achieving safe, reliable and cost-effective access to and from the International Space Station and low Earth orbit."

Heh, fine example of officialese. I spent a good chunk of my career drafting such stuff for Government ministers and senior officials!

Note there's a difference between the objective and the goal. The latter is contained within the former, but they're not the same thing. If they were, then instead of 'with the goal of achieving' they'd have put 'in order to achieve' or even just 'to achieve'. No, they wanted to preserve the possibility of other goals within the objective.

As for the goal itself, note that it's the ISS and LEO. We all know the ISS is in LEO, so it they were just thinking of the ISS why bother with the 'and LEO'? They wanted to preserve other options in LEO! (Makes obvious sense, really - the ISS won't last forever - but they don't want people saying 'this was just to get to and from the ISS and as there's no ISS you don't need it' without being able to reply 'it wasn't just ISS, we said and LEO'.

Also the objective is a crew space transportation capability. Note that there's no limitation to the ISS or even LEO here. (Strictly, the 'safe, reliable and cost-effective' doesn't apply generally to the objective either, though as getting to LEO is by far the most difficult bit, if you achieve it here you'll be a long way towards achieving it anywhere.) Also, the goal is to be 'achieved', but the objective is only to be 'facilitated' - it's a step on the way, but not necessarily the only or final one.

So, what NASA is saying is they want something with the potential to be developed into a not LEO-limited crew space transportation capability, or part of one, but it must also enable safe, reliable and cost-effective access to and from the ISS. But said in such a way that if you read it in a rush or with preconceptions you'll focus on the second bit and not notice the first.

This is all my interpretation, of course, and I may be wrong. But, if I'm right then being a space-taxi to the ISS is not the be-all and end-all of this competition!
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/01/2014 11:21 am
Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?
I was thinking about that and I think you don't actually need to completely turn the opposite cluster off, because their arrangement is not symmetrical. Anyone up for a simulation?

Huh?  Each cluster of two engines is exactly symmetrical to another cluster of two engines.  If you lose one cluster entirely, and the two clusters to the left and right of it are still firing at full thrust, you have to have the cluster opposite the lost cluster entirely off to avoid asymmetric thrust flipping the capsule end-over-end.
Each pair of cluster is symmetrical, but the 2 pairs are not. Also each cluster has actually some distance between nozzles, I wonder if there is something that can be squeezed from fine balancing the thrust of each engine, without simply shutting down the opposite engines.

OK, so assume you lose one cluster.  Call that Cluster A.  Call the opposite cluster Cluster C.  Call the other two clusters B and D.

If B and D are firing at full throttle, what happens, when you turn on C even a little?  Its true that you can compensate for a small amount of thrust from C by adjusting the thrust of the two engines in each of B and D.  The problem is that you need to balance the thrust from C through the plane that cuts through B and D.  So by reducing the thrust on the engine of B closer to C and the engine of D closer to C, you can balance the thrust again and have the vessel stay level.

But how much do you have to cut the thrust of those two engines in B and D?  The answer is by a lot more than the thrust of C.  That's because the engines in B and D are much closer to the plane that you need to balance around.  So C has a much larger arm.  The net result is much less overall thrust if you turn on C a bit and have to reduce some thrust in B and D.

If you lose A, the maximum overall thrust you can get while still keeping the craft upright is to entirely turn off C and keep the four engines of B and D at maximum throttle.

Each cluster is a pair.

If you lose one engine from cluster A, then only one engine from cluster C would be shut down (or both engines throttled by 50%).

Note also that each cluster contains a clockwise and counterclockwise member. IRobot seems to be suggesting that thrust is balanced across B & D when the clockwise engines are throttled in sync, and the counterclockwise ones in sync. Throttling clockwise on B &  counterclockwise on D (or vice versa) will introduce a small tilt moment, although the moment arm is very short for adjacent engines.

ISTM unlikely that the CoM of the payload / occupants would be so well centred that this would give enough control authority.

So, ISTM that if Dragon can survive two engines out, they'd better be in different clusters.

In the extreme case, if both A engines are lost, CoM needs to be on the C side of the B-D line, and some very delicate (probably unrealistic) throttling required from C. While the dracos could add a tiny bit of thrust / authority, I'd guess nowhere near enough to make up any shortfall.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: alang on 06/01/2014 11:31 am
Could you please spell that out more for non experts?
Are you saying that each member engine of a Super Draco cluster pair are angled with respect to each other?
If that is the case then presumably there is another slight angular (cosine?) loss and would you know what that is?
Is it safe to assume that the standard Draco thrusters become valueless during landing?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: charliem on 06/01/2014 11:32 am
I wonder if they are planning on flight testing that situation, losing a whole cluster.

Intuitively sounds quite difficult to compensate.

Depending of altitude the best solution could just be cut the engines entirely and use the parachutes (remaining superdracos could provide terminal deceleration 'a la soyuz' if necessary), but if said altitude is too low ... uh oh.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 06/01/2014 11:57 am
From the LIVE thread:

Has anyone noticed how the super-dracos angle is much steeper than previously thought.

Less than half the 45 degrees from vertical the first CGIs showed.

That will reduce thrust cosine losses from 29% to just 7%.

Not bad.

We can calculate backwards from performance numbers.

8 x 16400 is the maximum performance of the superdracos.

It will be run at sligthly lower pressure/thrust (at least initially) to be conservative about margins for reliability and reuse. I saw/heard the number somewhere -- it was 15XXX -- pity I do not remember the last digits. Does someone else remember derated thrust number for superdraco and where it came from?

If the 120000 axial trust figure is based on max performance, the efficiency after cosine losses is 91.5% (8.5%loss) and the angle about 24 degrees. If it is based on the slightly de-rated flight numbers, the efficiency will be better and the angle smaller. So I think we can at least say that the angle is not more than 24 degrees.

120000 for axial trust (and 16000 from the presentation) are rounded off numbers -- So the numbers will be approximate.

Have anyone found more accurate thrust numbers that are known whether they are max performance or flight performance? (We can move this to L2 if the numbers are not public)

I am not really an expert on this (just an engineer in a different field) so feel free to correct if I have made any mistakes in my calculations.

edit: Some additional points:

- I forgot about the difference between vacuum and sea level performance -- blushing in shame now for such a rookie mistake. I think the max performance number (16400lbf) is vacuum thrust. Another variable to add. Thrust isnt just an unqualified number -- it depends on ambient pressure, de-rating and maybe other stuff. Well it's rocket science after all.

- I am not 100% sure about the de-rating. I think that is what I heard/saw, but it might have been a misunderstanding, and it could for example have been the sea-level thrust I saw/heard.

- There is a number of 15000lbf floating around for superdraco thrust in news articles, but that is just a misunderstanding from journalists not knowledgeable enough to know about cosine losses. Its just the dragon axial thrust number (~120000) divided by 8.

I saw that baldusi had added that thrust number to the SuperDraco or DragonFly thread on Wikipedia.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 06/01/2014 01:24 pm
Elon claims that it can lose up to two engines and still land safely. Does that mean that it can lose ANY two engines? If both are on the same cluster, then the opposite cluster would have to be turned off too, leaving only four engines. So, if that is the case, it could lose up to FOUR engines, if those are the right four, right?
I was thinking about that and I think you don't actually need to completely turn the opposite cluster off, because their arrangement is not symmetrical. Anyone up for a simulation?

Huh?  Each cluster of two engines is exactly symmetrical to another cluster of two engines.  If you lose one cluster entirely, and the two clusters to the left and right of it are still firing at full thrust, you have to have the cluster opposite the lost cluster entirely off to avoid asymmetric thrust flipping the capsule end-over-end.
Each pair of cluster is symmetrical, but the 2 pairs are not. Also each cluster has actually some distance between nozzles, I wonder if there is something that can be squeezed from fine balancing the thrust of each engine, without simply shutting down the opposite engines.

OK, so assume you lose one cluster.  Call that Cluster A.  Call the opposite cluster Cluster C.  Call the other two clusters B and D.

If B and D are firing at full throttle, what happens, when you turn on C even a little?  Its true that you can compensate for a small amount of thrust from C by adjusting the thrust of the two engines in each of B and D.  The problem is that you need to balance the thrust from C through the plane that cuts through B and D.  So by reducing the thrust on the engine of B closer to C and the engine of D closer to C, you can balance the thrust again and have the vessel stay level.

But how much do you have to cut the thrust of those two engines in B and D?  The answer is by a lot more than the thrust of C.  That's because the engines in B and D are much closer to the plane that you need to balance around.  So C has a much larger arm.  The net result is much less overall thrust if you turn on C a bit and have to reduce some thrust in B and D.

If you lose A, the maximum overall thrust you can get while still keeping the craft upright is to entirely turn off C and keep the four engines of B and D at maximum throttle.

Each cluster is a pair.

If you lose one engine from cluster A, then only one engine from cluster C would be shut down (or both engines throttled by 50%).

Note also that each cluster contains a clockwise and counterclockwise member. IRobot seems to be suggesting that thrust is balanced across B & D when the clockwise engines are throttled in sync, and the counterclockwise ones in sync. Throttling clockwise on B &  counterclockwise on D (or vice versa) will introduce a small tilt moment, although the moment arm is very short for adjacent engines.

ISTM unlikely that the CoM of the payload / occupants would be so well centred that this would give enough control authority.

So, ISTM that if Dragon can survive two engines out, they'd better be in different clusters.

In the extreme case, if both A engines are lost, CoM needs to be on the C side of the B-D line, and some very delicate (probably unrealistic) throttling required from C. While the dracos could add a tiny bit of thrust / authority, I'd guess nowhere near enough to make up any shortfall.

Cheers, Martin
That's what I've been saying for several pages now Martin and sooner or later SpaceX will have to answer that failure mode recovery or even better yet demonsrate it...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: eweilow on 06/01/2014 01:38 pm
Been working on this (The Dragon part) over the last couple of days. It's not entirely accurate yet but it will eventually be 3D-printed! (F9R model is from http://www.blendswap.com/blends/view/73113 (http://www.blendswap.com/blends/view/73113))
How's the visualization of Dragon V2 on F9R? ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: guckyfan on 06/01/2014 01:39 pm
sooner or later SpaceX will have to answer that failure mode recovery or even better yet demonsrate it...

Or demonstrate that this failure mode is sufficiently unlikely to ignore it. Those two engines need to be on different propellant tanks and different pressurizing tanks. In that case total loss of both within few seconds of each other is extremely unlikely considering how robust and reliable this kind of engine is.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: eweilow on 06/01/2014 01:42 pm
sooner or later SpaceX will have to answer that failure mode recovery or even better yet demonsrate it...

Or demonstrate that this failure mode is sufficiently unlikely to ignore it. Those two engines need to be on different propellant tanks and different pressurizing tanks. In that case total loss of both within few seconds of each other is extremely unlikely considering how robust and reliable this kind of engine is.
I'd also imagine that since the engines are supposed to be used for aborts, SpaceX would have have enough confidence and qualification with the engines that they can be safely used in a propulsive landing?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ben the Space Brit on 06/01/2014 01:44 pm
sooner or later SpaceX will have to answer that failure mode recovery or even better yet demonsrate it...

Or demonstrate that this failure mode is sufficiently unlikely to ignore it. Those two engines need to be on different propellant tanks and different pressurizing tanks. In that case total loss of both within few seconds of each other is extremely unlikely considering how robust and reliable this kind of engine is.
I'd also imagine that since the engines are supposed to be used for aborts, SpaceX would deem them reliable enough to be safely used in a propulsive landing?

I doubt that 'deem' has anything to do with it. There has been many and will be further tests to give a degree of assurance as to that premise.


The biggest problem I have with Dragon-2 isn't in any way with its technology or design. My concern is that it is simply too big a leap forward from Dragon-1 to be available for operational use in a timely manner. The whole point in having the crew and cargo Dragon as variants of the same basic spacecraft was to accelerate the development process. Dragon-2 just has too many upgrades and modifications and this can only slow the process.

Slow compared to a hypothetical alternative that is more similar to Dragon 1 or slow compared to Dream Chaser and CST-100?  If you mean the former, I agree, but if you mean the latter I disagree.  And the latter is all that matters to the CCtCap competition.  Dream Chaser and CST-100 were starting from even less, and they are less far along today than Dragon 2.

It's the former and, given SpaceX's history of aggressively optimistic schedules that often end up slipping by years, I would have hoped that Elon would have learnt a little caution.

I'll defend this statement, for all it's really only opinion: If SpaceX had gone for a Dragon-1 derived crew vehicle, I suspect that finishing ahead of CST-100 and Dreamchaser is almost assured as it is just a mod of an already-flying vehicle. With Dragon-2, it only takes one serious slip due to an unforeseen equipment or structural dynamic incompatibility (vibration and the like) to have SpaceX finishing a distant third.

At the risk of sounding a defeatist, if SpaceX insists on making Dragon-2 its commercial crew product to NASA for the 2016-20 ISS missions, then I'm not convinced it will have flown with a crew before the end of CY2016.

Well, there's always a chance it will slip, but I think the chances of a crewed flight in 2016 are quite high.  Why do you think it's so unlikely?  They're far enough along that they've completed acceptance testing of the SuperDraco engines, they have pad abort and max-Q abort tests planned in the next 12 months, they have DragonFly tests planned in the next 12 months, they've already completed parachute drop tests, and they've already built the unit that they plan to fly to orbit on the first uncrewed flight.  That seems pretty far along to me, and on track for a crewed flight in 2016.

Systems integration is and always will be the killer. Building an actual space-ready prototype, ensuring that all the systems work together, determining how different the flight dynamic requirements might be due to the differing structure. All these things would be needed for a v.1-derived vehicle too but they would be simpler as they would be starting from a known set of data.

My fear is overstretch: They've set themselves too complex a task for too tight a schedule.

My hope at this point is that the Dragon-2 rollout has nothing to do with commercial crew and is a product that SpaceX are developing aside from their NASA interests for later introduction into the market. If they push ahead with a Crewed Dragon-1 (call it v.1.1, if you like) for NASA and then let Dragon-2 have an unhurried dev process like the reusable Falcon-9 core, then you have the best of both worlds.

I think they've been pretty clear that Dragon 2 is their CCDev/CCiCap/CCtCap vehicle.

That could be a fatal error on their part.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: malu5531 on 06/01/2014 01:55 pm
OK, so assume you lose one cluster.  Call that Cluster A.  Call the opposite cluster Cluster C.  Call the other two clusters B and D.

If B and D are firing at full throttle, what happens, when you turn on C even a little?  Its true that you can compensate for a small amount of thrust from C by adjusting the thrust of the two engines in each of B and D.  The problem is that you need to balance the thrust from C through the plane that cuts through B and D.  So by reducing the thrust on the engine of B closer to C and the engine of D closer to C, you can balance the thrust again and have the vessel stay level.

But how much do you have to cut the thrust of those two engines in B and D?  The answer is by a lot more than the thrust of C.  That's because the engines in B and D are much closer to the plane that you need to balance around.  So C has a much larger arm.  The net result is much less overall thrust if you turn on C a bit and have to reduce some thrust in B and D.

If you lose A, the maximum overall thrust you can get while still keeping the craft upright is to entirely turn off C and keep the four engines of B and D at maximum throttle.

Full throttle is only used in abort scenarios. At full thrust the 8 engines can accelerate the craft @ ~8 gee => one engine is enough for hoover (if only looking at thrust, not controlled flight), or eight firing at ~12.5% thrust.

If below the safe altitude for deploying the parachute, and two engines are lost on the same nacelle, call it "A", there are two ways to handle this;

1) Each of nacelle B and D reduce thrust to 0% on the engine closest to nacelle C and throttle up the one furthest away to 50%. Nacelle C is throttled down to near zero and used to balance the craft. This thrust is enough for the craft to hover and for a controlled decent.

2) Nacelle B and D throttle up both engines to 100%. Nacelle C is throttled down to 0%. The craft accelerates up at 4 Gee and reach sufficient altitude to deploy the parachutes and proceed with a parachute landing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 06/01/2014 01:58 pm
I saw that baldusi had added that thrust number to the SuperDraco or DragonFly thread on Wikipedia.

Excellent.

But there is one more thing that should be fixed there.

The same source document confirms that the 16400lbf thrust number is a sea level number, but the superdraco infobox on the right side of the wiki page still erroneously says that it is a vacuum number. See the superdraco thread from this message (http://forum.nasaspaceflight.com/index.php?topic=29855.msg1207918#msg1207918) onward for more if needed.

Maybe I'll remember to notify him if the page does not get updated soonish by him or others, but I will not guarantee it...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Giovanni DS on 06/01/2014 02:48 pm
...
V2 has a single door, and ability for the egress of seven people that have to be in very special suits is probably going to get talked about. Electrical hazards inside the cabin with water also would be a concern. 
...
There is no way the FAA would allow these propellants to be scattered over a populated area if an abnormal or emergency condition were to occur.  The US military has shot down a satellite because it contained these materials and had a risk of contaminating populated areas.  Not to mention the Columbia disaster which scattered toxic materials over a huge area.

I would also add the added risk for locusts and rats infestations on the ISS caused by inappropriate procedures.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AncientU on 06/01/2014 03:42 pm

It makes no sense to me why taxpayers are paying for animals/insects in space.  But that is another great topic.

You're right... we should use humans, but they eat too much and are noisy.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mongo62 on 06/01/2014 03:54 pm

It makes no sense to me why taxpayers are paying for animals/insects in space.  But that is another great topic.

You're right... we should use humans, but they eat too much and are noisy.

Not to mention that cleaning their cages is a real chore.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Coastal Ron on 06/01/2014 03:59 pm
But there has been some news items that any new flight vehicle program has to meet the safety approvals agreed to by congress.  So much of this really is going to take front stage at some point.  Cannot say now that NASA will have any ability to make a choice if Congress holds final approval because of crew safety.

I haven't heard that - is this an unsubstantiated rumor or is there a reference you can provide?

Quote
With the v2 unveil, Elon opened the hatch with an outward an upward motion.  Under abnormal or emergency operations, one can just imagine the FAA asking how somebody is gonna open the door if the vehicle has fallen over onto the door!  If the vehicle is under water...

Why the heck would it be underwater?  Haven't you seen how high out of the water the current Dragon floats?

The only reason a Dragon spacecraft would be underwater is because the interior floods, and if the interior is flooded there won't be any pressure differential holding the door closed.

If the Dragon lands on terra firma and falls over for some reason, they can always use the NDS docking hatch to exit the vehicle.

Quote
It makes no sense to me why taxpayers are paying for animals/insects in space.  But that is another great topic.

Animals are low-cost analogs in place of humans when doing health related research.

As to insects, you are aware that the ISS is a National Laboratory, right?  That there is science being done for commercial as well as scientific reasons?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/01/2014 04:01 pm

It makes no sense to me why taxpayers are paying for animals/insects in space.  But that is another great topic.

You're right... we should use humans, but they eat too much and are noisy.

Not to mention that cleaning their cages is a real chore.
That commode issue...again?
At least PETA doesn't object when we experiment on them.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: douglas100 on 06/01/2014 04:02 pm

....If the Dragon lands on terra firma and falls over for some reason, they can always use the NDS docking hatch to exit the vehicle.
Quote

Yep, as long as they're also able to open the nose cone.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 04:22 pm
If the Dragon lands on terra firma and falls over for some reason, they can always use the NDS docking hatch to exit the vehicle.

Hollywood style, with guns blazing taking out a bunch of angry gorillas in middle of Sub-Saharan jungle where they landed.
Meanwhile in real world i'm sure the crews are content to wait until pad crews arrive - with a crane, if really necessary.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/01/2014 04:25 pm
....If the Dragon lands on terra firma and falls over for some reason, they can always use the NDS docking hatch to exit the vehicle.
Quote
Yep, as long as they're also able to open the nose cone.
The nosecone/hatch would be the green Frunk button on the keyfob Doug.
-don't press the red button. Nobody does that -unless they're out of ammo.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/01/2014 05:07 pm
Risks are typically categorized by probability and consequence... (And they are usually categorized by someone on the absolute borderline of what is considered reasonable)...
...
With the v2 unveil, Elon opened the hatch with an outward an upward motion.  Under abnormal or emergency operations, one can just imagine the FAA asking how somebody is gonna open the door if the vehicle has fallen over onto the door! If the vehicle is under water, the v2 door looks like a hazard to the crew as they would have to push it outward with a high hydraulic force keeping it shut.
You are ignoring the lessons learned from the Apollo 1 disaster.  Capsule doors open out specifically for safety reasons, not in spite of them. The people that build spacecraft know these things, even the young upstart ones.

I have to ask. How does a space capsule that floats like a cork get under water? And if it falls on it's side and the door opens in, then what? Tunnel out with shovels?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: alang on 06/01/2014 05:13 pm
With respect to hypergolic fuel toxicity and other safety issues:
A problem for casual spaceflight observers is how to judge potential improvements:
https://www.google.com/patents/US8382922
Maybe SpaceX are making an informed gamble on possible progress in this area?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 05:19 pm
With respect to hypergolic fuel toxicity and other safety issues:
A problem for casual spaceflight observers is how to judge potential improvements:
https://www.google.com/patents/US8382922
Maybe SpaceX are making an informed gamble on possible progress in this area?

There are other potential less hazardous hypergolics on the radar, see this thread (http://forum.nasaspaceflight.com/index.php?topic=29719.0) or this (http://forum.nasaspaceflight.com/index.php?topic=32444.0;all)

Its not inconceivable that a few years down the road they might want to migrate their thrusters to one of these. They'll still be toxic, just less so.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/01/2014 05:46 pm
Again, I don't see a lot of technical reasons why this type of propulsive landing with parachute backup would not work out to be at least slightly more reliable than helicopters.
In the theme of a party thread....
{snip}
You are ignoring the lessons learned from the Apollo 1 disaster.  Capsule doors open out specifically for safety reasons, not in spite of them. The people that build spacecraft know these things, even the young upstart ones.

I have to ask. How does a space capsule that floats like a cork get under water? And if it falls on it's side and the door opens in, then what? Tunnel out with shovels?

I'd get out of the capsule the same way anybody does when their car suddenly tips over on its side during the hazardous parallel parking maneuver.
As far as corks, don't be a skeptic, a giant whale could mistake the capsule for a marshmallow and swallow it while submerging to a great depth then disappointed at the tangy taste, spit the capsule out. The most terrifying for the Astronaut though is the cry of a pod of average size whales; "Water Polo!"


Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/01/2014 05:58 pm
You know, in the sixties, people did some crazy stuff (flying around in capsules).  This entire commercial crew program is really an adventure in regressive psychology based on apparent successes with Apollo -v- Shuttle.  As we all know, the shuttle was cancelled primarily due to safety.  Is anything looking safer than shuttle?   To me v2 is looking worse.

SpaceX are planning to fly DragonFly multiple times to prove out the engines and control systems.

By making the later flights self-contained (Dragon does both the lofting and the landing), it looks to me like they could afford to make additional test flights if they turn out to be needed.

Dragon also has a LAS that Shuttle did not, does not expose it's heatshield during launch, and F9 will have flown multiple times before the first human-bearing flight.

Just a few of the things that spring to mind.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/01/2014 06:02 pm
With the v2 unveil, Elon opened the hatch with an outward an upward motion.  Under abnormal or emergency operations, one can just imagine the FAA asking how somebody is gonna open the door if the vehicle has fallen over onto the door!  If the vehicle is under water, the v2 door looks like a hazard to the crew as they would have to push it outward with a high hydraulic force keeping it shut.

Dragon has a pressurisation system. If the door is held shut due to hydraulic pressure from outside, just vent more gas inside to equalise pressures.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 06:06 pm
By the way, Soyuz, the most reliable manned craft in history (?), do propulsive assist landing.

Soyuz had a decompression event killing 3 cosmonauts and a parachute failure killing 1 lone cosmonaut over 122 missions and multiple generations. Space Shuttle had a heat shield fail and a booster fail killing 2 crews. Apollo fire killed 3 astronauts on the pad with 12 manned missions. Shenzou has had no fatalities over 5 missions.

Loss of crew event:
Soyuz:1.6%
Shenzou: 0%
Apollo: 8.3%
Shuttle:1.5%

Ah, thanks! But we should count individual risk, right? I'm sure that is how the astronauts want to see it, as apart from the public. Akin to how planes are the most secure transportation, but the loss of an airplane makes the news instead of the ghastly death tolls from cars.

Loss risk/individual:
Soyuz: 1.1 %
Shenzou: 0.0 %
Apollo: 8.3 %
Shuttle:1.5% (assuming typical 5 crew and 133 missions; http://en.wikipedia.org/wiki/Space_Shuttle)

That was the lower figure for Soyuz that I seemed to remember.

Good point on Shenzou. Is 5 missions enough to establish reliability? (I assume you make a binomial statistic estimate, but I have no time.) Shenzou has a Soyuz heritage and I assume do propulsive assist.

Since we are scraping the bottom of the barrel (but I'll leave out the other capsules), X15 and SS1 has done (suborbital) space flights. Both land as gliders, I think, so we can contrast them, together with the Shuttle, to chutes for the landing phase only.

Loss risk/individual:
X15: 0.0 % (2 space flights, none killed I think).
SS1: 0.0 % (3 space flights)

Of course, the Shuttle with its long record pins the average loss risk for gliders. But chutes in sea (Apollo) are the worst.  :o  ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 06:09 pm
That's what I've been saying for several pages now Martin and sooner or later SpaceX will have to answer that failure mode recovery or even better yet demonsrate it...

Why?  That's a failure mode that requires the simultaneous failure of two independent systems.  Every vehicle has some failure mode of two independent systems that results in loss of crew if the failures happen at the wrong point in landing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Helodriver on 06/01/2014 06:13 pm
With the v2 unveil, Elon opened the hatch with an outward an upward motion.  Under abnormal or emergency operations, one can just imagine the FAA asking how somebody is gonna open the door if the vehicle has fallen over onto the door!  If the vehicle is under water, the v2 door looks like a hazard to the crew as they would have to push it outward with a high hydraulic force keeping it shut.

Dragon has a pressurisation system. If the door is held shut due to hydraulic pressure from outside, just vent more gas inside to equalise pressures.

Cheers, Martin


There is always the docking hatch at the top of the vehicle as a secondary exit. Not as fast or convenient, but available.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 06:21 pm
OK, so assume you lose one cluster.  Call that Cluster A.  Call the opposite cluster Cluster C.  Call the other two clusters B and D.

If B and D are firing at full throttle, what happens, when you turn on C even a little?  Its true that you can compensate for a small amount of thrust from C by adjusting the thrust of the two engines in each of B and D.  The problem is that you need to balance the thrust from C through the plane that cuts through B and D.  So by reducing the thrust on the engine of B closer to C and the engine of D closer to C, you can balance the thrust again and have the vessel stay level.

But how much do you have to cut the thrust of those two engines in B and D?  The answer is by a lot more than the thrust of C.  That's because the engines in B and D are much closer to the plane that you need to balance around.  So C has a much larger arm.  The net result is much less overall thrust if you turn on C a bit and have to reduce some thrust in B and D.

If you lose A, the maximum overall thrust you can get while still keeping the craft upright is to entirely turn off C and keep the four engines of B and D at maximum throttle.

Full throttle is only used in abort scenarios. At full thrust the 8 engines can accelerate the craft @ ~8 gee => one engine is enough for hoover (if only looking at thrust, not controlled flight), or eight firing at ~12.5% thrust.

If below the safe altitude for deploying the parachute, and two engines are lost on the same nacelle, call it "A", there are two ways to handle this;

1) Each of nacelle B and D reduce thrust to 0% on the engine closest to nacelle C and throttle up the one furthest away to 50%. Nacelle C is throttled down to near zero and used to balance the craft. This thrust is enough for the craft to hover and for a controlled decent.

2) Nacelle B and D throttle up both engines to 100%. Nacelle C is throttled down to 0%. The craft accelerates up at 4 Gee and reach sufficient altitude to deploy the parachutes and proceed with a parachute landing.

That seems reasonable.  I hadn't been considering how throttled-down the engines will be during a normal descent.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 06:25 pm
Planes don't land propulsively.

More seriously, are we having some interpretation issues? Only gliders don't land using engines.

Rather than getting bogged down over what exactly "propulsive" means, let's get to the point.


Oh!? I like that. Thanks for the help!

The point, I think, is that airplanes don't automatically crash if they lose propulsion during their landing approach.  They can potentially glide to a safe landing.  However, it's also true that if a plane loses all propulsion on its final approach there is a significant danger it will crash, and many planes have crashed in exactly that situation.

Okay, but that is not a clear point even if clearly expressed. This vehicle will not automatically crash either. It has to loose more than 2 engines to start approaching crash, they may start propulsion over sea, there may be time to pop the chute et cetera.

Also, since we are on to planes, aren't "anything you can walk away from is not a crash" the better approach here? The fall speed may be survivable after some propulsion, et cetera. It's a nitpick, I know, but we were just comparing risk for loss of crew. Risk for damage is much harder to assess.

Which brings me back to my original point by way of the crash risk you point out, if there is still a risk for planes as compared with chutes, why do they choose to land with wings?

I think it is because NASA policy isn't strictly applicable to "real life". But again, I think NASA is the customer that will overrule, by way of the process, what other customers may decide later.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/01/2014 06:28 pm
Again, I don't see a lot of technical reasons why this type of propulsive landing with parachute backup would not work out to be at least slightly more reliable than helicopters.
In the theme of a party thread....

The concept of operations for safety v2 looks like it is way off.  There is a lot more that needs to be thought about with this concept. Helicopters do not require the passengers to wear Class 8+ hazmat suits for normal egress. 

Neither does Dragon V2.  This has been covered in other posts.  Just because there are hazardous materials in tanks doesn't mean people can't safely be around the vehicle without suits.  The combustion products are not toxic, and they'll know if there's a leak.

V2 has a single door, and ability for the egress of seven people that have to be in very special suits is probably going to get talked about. Electrical hazards inside the cabin with water also would be a concern. 

It only goes in the water in an emergency.  In an emergency, a 737 also goes in the water, and it requires a lot more people to go through each emergency door.  A 737 also has the same potential issues with water and electrical systems.

Egress from a helicopter is typically performed using multiple doors and in some cases.... windows.  Navy pilots have to practice water landing egress from the helicopter upside down and in the dark. 

There is no way the FAA would allow these propellants to be scattered over a populated area if an abnormal or emergency condition were to occur.  The US military has shot down a satellite because it contained these materials and had a risk of contaminating populated areas.  Not to mention the Columbia disaster which scattered toxic materials over a huge area.

I think v2 is simply going to be a museum queen or is really intended for operations on Mars.  For NASA commercial crew, this has to be a miss. 

But the design is a very great effort.

And yet NASA has reviewed this design multiple times and it has passed those design reviews.  NASA considers it safe enough.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 06:30 pm
References, please.  :P
More seriously, are we having some interpretation issues?

Suffice it to say that all of your examples are either comparing apples and oranges (aircraft landing vs. propulsive spacecraft landing) or simply wrong... Soyuz is not propulsive landing, only some solids fired at the last moment to cushion the impact.

I think the error is on your side, since I wrote propulsive assist, and was discussing the meaning of "landing with chutes".

Apples and oranges... It's not clear, see my response to ChrisWilson68. But since you think we can't do comparisons, I think you lose the possibility to analyse the landing until it has proven itself. I can live with that too.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 06/01/2014 06:39 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 06/01/2014 06:41 pm
SpaceX's proven history with NASA flying Dragon V1 likely gives them a huge advantage in this 3 way competition. I will be shocked if SpaceX is not picked as the winner.

In terms of generating interest in space, Boeing and Dream Chaser will be huge disappointments. I can imagine the hate mail that NASA will get if they don't pick SpaceX Dragon V2. Does anyone think the same level of NASA hate would happen by Boeing or Dream Chaser losing? So does a tie go to SpaceX in this competition? :-) I am sure that will be a topic of discussion in this process. It may not be on the official list of items to evaluate, but it will be discussed.

SpaceX wins the tie because of the extra public interest in space they bring to the table. No bucks without Buck Rogers / Iron Man (aka Elon Musk). Just my opinion.


A lot of folks would say that dream chaser has elicited more, maybe far more, public interest , support and attention.  But again, considering NASA wants a taxi in place by 2017-21018, they could well go the route of what works instead of what exhilarates.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 06/01/2014 06:46 pm
In terms of generating interest in space, Boeing and Dream Chaser will be huge disappointments. I can imagine the hate mail that NASA will get if they don't pick SpaceX Dragon V2. Does anyone think the same level of NASA hate would happen by Boeing or Dream Chaser losing? So does a tie go to SpaceX in this competition? :-) I am sure that will be a topic of discussion in this process. It may not be on the official list of items to evaluate, but it will be discussed.

That isn't the mission. The objective of all this is to find an affordable way for the US to get crews to LEO. If Boeing or DC wins, extremely avid SpaceX fans are the only persons NASA will get hate mail from.

SpaceX wins the tie because of the extra public interest in space they bring to the table. No bucks without Buck Rogers / Iron Man (aka Elon Musk). Just my opinion.

And that isn't the mission either. You've reduced the whole thing to nothing more than a PR exercise.

THANK YOU.  MISSION. MISSION. MISSION. It keeps getting forgotten here.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 06/01/2014 06:53 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

They have to launch with that prop anyways in case there is an abort.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 06:54 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Ike17055 on 06/01/2014 06:57 pm
The inherent weaknesses of the shuttle systems are exactly why we are havin this debate at all.  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.if there is a newfound emphasis on safety and simplicity/ reliability,specifically in the wake of a catastrophic burnthrough, this should not be a surprise. It is added risk.

The "catastrophic burnthrough" on Columbia had nothing to do with hatches in its heat shield, and everything to do with design details that Falcon 9 and Dragon do not share.  Your argument relies on irrelevancies.

Read the post. The burnthrough issue is of greater concern overall. My post even stated the gear doors were not the culprit, but they WERE the first suspected cause due to the long standing concern over them. The overall effect of Columbia was a greater emphasis on acknowledging risks that were somewhat pooh-poohed previously.  Follow the narrative instead of mauling the context.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 06/01/2014 06:59 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

You might have a point if the LAS & landing engines (SD) used a separate propellant supply. But they don't - it is shared with the Draco engines.

Why is this important? Because that is margin that is available to increase probability of mission success, should the Dragon be inserted into a lower than expected orbit (abort to orbit scenario). Or even to allow more attempts to dock at ISS.

If they use more than what is needed for a full propulsive landing? Not the end of the world - the parachute is still available.

And if the LV is capable of lifting that extra mass to orbit - which isn't much (maybe 50% more propellant than Dragon 1 at most) - then why not?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/01/2014 07:08 pm
Thanks everyone who pitched in on "propulsive landing", I think the helicopter analog is both apt and it helped me to clear out the confusion I had re wing help. I guess a plane landing with engines have "propulsive assist" like Soyuz then.

Since it's a party, has anyone noticed that the SD wrap of the heat shield makes it the largest (longest shielding length) of all ablative shields (that I know of)?

The Orion is a puny 5.0 m; I used an Elon shaped yard stick and his lack of perspective  ;) to estimate the wrap to ~ 1.3 - 1.5 m, getting a minimum ~ 6.5 m shielding length assuming the V2 base is the same as V1 at minimum.

Since the Orion controls, LAS, SM, landing mode et cetera seems all dated compared to state-of-the-art touch screens, LAS, batteries, propulsive landing et cetera of the V2, I thought it would suit the theme while we wait for the PICA-X superior heat shield that's supposed to beat the verniers off of Orion in the remaining area of BEO return.  ::)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 07:16 pm
Parachutes aren't infinitely reliable, either. Only 4 fatal in-flight disasters occurred, two on Shuttle (uses wings mostly, not parachute except for braking at the end) and two on Soyuz. The first orbital spaceflight fatality occurred because the main parachute didn't deploy properly and the reserve parachute got tangled up with the drogue chute. Dragon V2 is the only spacecraft that has 2 independent recovery systems: the propulsive landing (tested in-flight, with redundancy) and the backup parachute. So I think the propulsive landing with parachute backup is actually safer than any of the other options.

And heck, if ALL power is lost to the vehicle, the crew can still deploy the reserve parachute manually and survive. For Shuttle or Dreamchaser, you'd be dead if all power is lost (although that's not likely to happen, of course).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 06/01/2014 07:30 pm
Any reference to fan boys or trolls will result in your entire post being deleted.

Are we crystal clear on that?

If you THINK someone is trolling, you hit report to moderator. You do NOT respond to the post. All that will happen is you'll lose your post, so you'll have wasted your time, the mods time and those people reading it.

THINK before posting.

Any more nonsense on this thread and people will have their posting privileges removed.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 07:37 pm
Dragon V2 is the only spacecraft that has 2 independent recovery systems: the propulsive landing (tested in-flight, with redundancy) and the backup parachute. So I think the propulsive landing with parachute backup is actually safer than any of the other options.
Exactly, just a small quibble. Better way of stating this : it will likely be more "reliable than any of the other options".

To expand on what i said before here, IMHO "safe" is a highly subjective characterization, whereas "reliability" can be objectively analyzed and measured.

Majority of people will never consider bungee jumping as a "safe activity", and the reliability of the systems involved never even enters the picture. A the same time they'll happily let their daughters join a cheerleading squad, which statistically a pretty good way of getting paralyzed for life (http://nypost.com/2013/09/13/most-dangerous-sport-for-female-athletes-cheerleading/)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 06/01/2014 08:01 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

That's your issue, it's obviously not Musk's.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 06/01/2014 08:16 pm
The inherent weaknesses of the shuttle systems are exactly why we are havin this debate at all.  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.if there is a newfound emphasis on safety and simplicity/ reliability,specifically in the wake of a catastrophic burnthrough, this should not be a surprise. It is added risk.

The "catastrophic burnthrough" on Columbia had nothing to do with hatches in its heat shield, and everything to do with design details that Falcon 9 and Dragon do not share.  Your argument relies on irrelevancies.

Read the post. The burnthrough issue is of greater concern overall. My post even stated the gear doors were not the culprit, but they WERE the first suspected cause due to the long standing concern over them. The overall effect of Columbia was a greater emphasis on acknowledging risks that were somewhat pooh-poohed previously.  Follow the narrative instead of mauling the context.

I read the post, and it was still irrelevant.  The concerns with the landing gear doors on Columbia was not whether hot gases leak through the seams, it was whether the doors had come open, since the first indication of trouble was with the tire temperatures and pressures in the wheel well. 

Your implication here seems to be that the Dragon designers are ignorant of the basic laws of physics and the gas laws.  Only you, in your camel's hair cloak, your voice crying in the wilderness, are alert to the real dangers.  The tiny seams created in the heat shield by the Dragon's foot pads do not constitute some unknown and unconsidered risk, that only YOU seem to be aware of.  Those can be understood through modeling and wind tunnel testing for starters, and if you're still not convinced they'll have an unmanned test flight to expose them to real-world conditions. Small gaps in heat shield coverage that do not create flow-through channels have never been a concern, because they don't create pathways for burning gases.  The shuttle was able to lose dozens of heat shield tiles on some flights without consequence because the exposed area was small and did not create channels for gas flow, unlike an opening in the wing leading edge.

There are plenty of things to be concerned about in spaceflight without pulling fears out of thin air.



Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/01/2014 08:33 pm
Something more appropriate for a party thread, a highly scientific study attached.

As can be seen, Houston does not have a problem, Washington DC is googling like mad and Moscow is clearly interested.

Explore more here : http://www.google.com/trends/explore#q=%2Fm%2F0bw2gf
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 06/01/2014 08:35 pm
Space X has lots of flight experience with dragon, but then embrace how different this craft is without without seeing the contradiction. 

And that's a really good point.

Imagine what would happen if NASA rejected the design because of the retrorocket approach? That would be a conservative engineering decision, but I suspect that it might result in a lot of kvetching here...

Dragon 2 can land with chutes, and will, long before NASA would allow propulsive landings with their cargo/people.

To correct my statement.

At the end of the Helodriver video, Garrett Reisman interview, said the first DV2 (my preferred shorthand), would be propulsive landings. But of course, nothing is set in stone. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ricmsmith on 06/01/2014 09:05 pm
I'm not sure how many hatches people expect it to have. There's the main entry/egress hatch and the docking hatch. Two hatches should be sufficient to mitigate against most realistic risk scenarios.

Some people also seem to be a little hysterical about additional or the perceived addition of risk. Remember it's not about the elimination of all risk. Some risk will always be present, as space travel is inherently unsafe. It's about the management and understanding of acceptable risks.

Specifically on the powered decent landing system. Some contributors seem to be under the impression that this is extra unnecessary risk and or weight that is being taken on. It is neither; the powered descent system utilises the abort escape system thrusters. This is weight has to be taken to and returned from orbit anyway so it may as well be used for something useful. And returning to a fixed point of landing hopefully the original launch site cuts a lot of costs. Having that degree of control is inherently safer than not having it. Parachutes although tried and tested are not without risks themselves and in any case will still be available in case of the powered descent engines failing. Assuming Space X's failure modes for this system can be well understood, and I have to assume they can be, there's no reason for anyone to be getting overly concerned about them.


[The above is all in my humble opinion]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: LouScheffer on 06/01/2014 09:07 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

So?  This obsession with mass has to go at some point if we are ever to get the price of space flight down.  1 ton is something like 12% of the total mass.  If it makes operations easier/simpler/safer/faster it might be a bargain.

By analogy, imagine a civil engineer scoffing at an 8 ton bridge:  "That's absurd - you can make a bridge that weighs only 7 tons and carries the same load!  You just need to inspect it after every truck crosses....."
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 09:15 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

That's your issue, it's obviously not Musk's.
Additionally, it's abort propellant as well. Both launch abort AND (potentially? If it shares systems with regular Dracos...) abort-to-orbit propellant. Also, they only need a backup chute, not a cushy-landing one. And anyway, the issue of mass is just a question of costs, ultimately. Propulsive landing allows much easier reuse than either airbag landing or splashdown, so that metric ton of propellant or so buys you a pretty space capsule which can be easily reused.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: deruch on 06/01/2014 09:20 pm
I know that the propulsive landing discussion has been around the block a few times already, but I wanted to bring up an additional point that hasn't been raised (so far as I've seen).  I'm not at all knowledgeable on the physics, so if I'm way off base I'd appreciate it if those who know can steer me straight.  Is it possible that having the SDs integrated, with the prop to do a propulsive landing, would allow the F9 with Dragon v2  to follow a "steeper ascent trajectory" (not sure if correct term).  I recently happened to read Wayne Hale's enlightening (and fascinating) blog postings about abort black zones at http://www.spaceref.com/news/viewsr.html?pid=29847 (http://www.spaceref.com/news/viewsr.html?pid=29847).  In them he writes: 

Quote
"...Satellite launchers seek the most efficient way to get to orbit -- they want to use the least "energy" to get the most payload to orbit. Simplistically, one would want to get to altitude first, then accelerate, accelerate, accelerate. So most expendible[sic] satellite launch vehicles go high early and then pitch over toward the horizontal for the largest part of the rocket burn.

Unfortunately, this does not work well if you want to protect a crew from a failure of the rocket. Because a steep, suborbital ballistic reentry leads to extreme heating and extreme g-loads. This is not obvious, so lets examine this closely.

In a typical planned re-entry, the capsule or shuttle enters at a fairly shallow angle so that it encounters thicker atmosphere gradually. As the re-entry proceeds, the speed (kinetic energy) is bled off gradually limiting the maximum heating temperature and holding structural loads relatively low. For a suborbital ballistic type re-entry, the trajectory is quite steep, encountering the denser parts of the atmosphere while the speed and energy is quite high leading to a high heat impulse and very high structural loads.

The trajectories for manned spacecraft try to avoid these steep re-entries even on an emergency case. For complete loss of thrust this is not always possible....

...An expendible[sic] rocket sending a satellite on a one way trip to orbit optimizes its trajectory by lofting high early on. If an engine fails, the mission would be lost no matter what the trajectory; abort modes and crew rescue are not a consideration. There has been some speculation that if an EELV were to be used to power the Orion capsule into orbit, there would be large parts of the trajectory where early aborts would cause loss of the capsule and crew during re-entry: the dreaded black zone. By adjusting the launch trajectory lower, these black zones can probably be eliminated -- but at a cost. The cost is performance: mass to orbit is decreased by flying a safer, more depressed trajectory...."

Is it possible that by using the SuperDracos -- either short, periodic bursts or some other mode I haven't thought of -- Dragon v2 would be able to minimize (and thereby survive) the g forces and heating of a steep ballistic re-entry in the event of a high altitude failure.  [This assumes that the failure doesn't require a very large abort burn.  But as I saw debated earlier, a high altitude abort might not need much acceleration (a past example had TWR ~0.25)].  They could afford to use all the remaining prop for this "braking maneuver" and then later land under canopy.  If this could be so, then that would allow SpaceX to fly a more efficient (i.e. steeper) ascent trajectory.  Could the efficiency gains of this ascent profile make up for the inability to jettison the LAS? 

My premise may not apply, as the Dragon v2 flights may have been planned to follow a steep trajectory regardless of this capability (I am not familiar with any published material on this issue.  As I am much less well informed than many of the people posting on these fora, maybe others have heard/read something about this?).

Thoughts?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Nascent Ascent on 06/01/2014 09:25 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/01/2014 09:30 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA
No, people always find ways of whining about stuff that isn't their pre-approved solution.  Their design criteria isn't to satisfy armchair critics, they need a reliable and inexpensive and capable system.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 06/01/2014 09:41 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/01/2014 09:58 pm
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.
Yes, it's a trade off. I think DC is lovely, I really do. As a matter of fact I hope that Dragon V2 and DC are successful and get selected as I think that down selecting to a single craft is a bad idea.

What does the extra mass matter if the craft can perform it's mission safely and reliably? Engineering is the art of trade offs, there are no perfect designs.  There is no Platonic ideal space craft. Dragon carries the fuel up, and uses it on the way down.  DC carries the wings up and uses them on the way down.  Those wings are completely useless on the way up, they add mass and drag during launch and mass the entire mission.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/01/2014 10:08 pm

The basic principles don't care whether you've "worked on one".

I know enough to differentiate between the pressure wave, the expanding gas front, and the debris, and know how they're affected by altitude.

I know enough to know that engine bells can be dented pretty easily by flying debris.

I know that a dented engine bell will produce off-axis thrust, at best.

I know that if t/w is 0.25, you're only moving away from the exploding stage at, well, 0.25g.  If the engine bell is still ok. 


You don't know enough to know which basic principles matter.  An abort system that supplies over 10g's during upperstage flight is not needed.  All that is needed is a system that provides separation. It doesn't matter how far to get away.   Just getting away is enough.   There is no threat from debris, which was minor in the first place because upperstages don't blow up (show an upperstage that has blown up during ascent since the 80's).  Anyways, Apollo, CST-100, SNC have/had buffer between them and the upperstage, which negates the effects from debris.  Entry is happening no matter what, so the amount of distance from the stage don't matter.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/01/2014 10:13 pm

They got lucky and still experienced very high g's.

From entry and not the abort from the stage
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Garrett on 06/01/2014 10:40 pm
If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.
DC is carrying wings and an aerodynamic flying body shape to orbit and back. There's no absolute winning solution.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 06/02/2014 12:58 am
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.
Yes, it's a trade off. I think DC is lovely, I really do. As a matter of fact I hope that Dragon V2 and DC are successful and get selected as I think that down selecting to a single craft is a bad idea.

What does the extra mass matter if the craft can perform it's mission safely and reliably? Engineering is the art of trade offs, there are no perfect designs.  There is no Platonic ideal space craft. Dragon carries the fuel up, and uses it on the way down.  DC carries the wings up and uses them on the way down.  Those wings are completely useless on the way up, they add mass and drag during launch and mass the entire mission.

It matters as SpaceX has to launch it on a rocket that's 50% by GLOW.  Everything has a cost, and that's one cost for propulsive landing of the stage and the payload.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TrueBlueWitt on 06/02/2014 01:07 am
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.
Yes, it's a trade off. I think DC is lovely, I really do. As a matter of fact I hope that Dragon V2 and DC are successful and get selected as I think that down selecting to a single craft is a bad idea.

What does the extra mass matter if the craft can perform it's mission safely and reliably? Engineering is the art of trade offs, there are no perfect designs.  There is no Platonic ideal space craft. Dragon carries the fuel up, and uses it on the way down.  DC carries the wings up and uses them on the way down.  Those wings are completely useless on the way up, they add mass and drag during launch and mass the entire mission.

It matters as SpaceX has to launch it on a rocket that's 50% by GLOW.  Everything has a cost, and that's one cost for propulsive landing of the stage and the payload.

Lee Jay.. What about the cost of Ocean recovery, and the time and cost of refurbishment after being exposed to sea water, vs a land landing?  Let's keep this in perspective. I will be interested to see if they EVER re-use a Dragon V1 that has landed in the ocean.  Losing a ton or two to orbit, but being able to rapidly re-fly the capsule, vs major overhaul or building a new one sure seems like a major cost SAVINGS to me. Especially if they are also re-flying the cores.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AncientU on 06/02/2014 01:09 am
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.
Yes, it's a trade off. I think DC is lovely, I really do. As a matter of fact I hope that Dragon V2 and DC are successful and get selected as I think that down selecting to a single craft is a bad idea.

What does the extra mass matter if the craft can perform it's mission safely and reliably? Engineering is the art of trade offs, there are no perfect designs.  There is no Platonic ideal space craft. Dragon carries the fuel up, and uses it on the way down.  DC carries the wings up and uses them on the way down.  Those wings are completely useless on the way up, they add mass and drag during launch and mass the entire mission.

It matters as SpaceX has to launch it on a rocket that's 50% by GLOW.  Everything has a cost, and that's one cost for propulsive landing of the stage and the payload.
But the benefit is that you still have a stage and payload to refly instead of a new reef for the fishies and some interesting scrap aluminum. 

The cost of 'expendible' includes making human spaceflight a dead end. 
We need to get over it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Micahgtb on 06/02/2014 01:23 am
If this has been covered let me know but,

Does anyone have an idea on what kind of extra wear the 4 tiles on the legs will have since they are supporting the weight of the capsule along with re-entry wear.  Are they just going to swap out the 4 tiles or can they make it through the 10 flights?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 01:32 am
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

Why would SpaceX care about a small number of critics on the internet?  The people evaluating the design at NASA are smart and knowledgeable enough to realize propulsive landing is a plus, not a minus.  As, I suspect, are most of the people on NSF.  Not all, but most.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 01:35 am
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.

Making the landings safer and making it easier and faster to re-use the craft are more important to SpaceX than bringing a bit more mass to orbit.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 01:40 am
My issue with propulsive landing isn't safety, it's mass.  They have to keep the chutes anyway, and they have to carry the landing prop for the entire mission.  And a back of the envelope calc suggests that 1-2 metric tons of prop.

And as has been discussed a lot here, this mass is dual use - it doubles as LAS propellant. That is a good engineering trade.

If they weren't using it for landing, they could use it as a third stage to insert a lot of additional mass into orbit, which is exactly what DC is doing since they don't have to carry it through to landing.

The dV for landing is very small, and you need to subtract from that the weight and volume of a secondary parachute...   

As for DC, which you keep bring up, payload mass fraction is not its shining attribute you know.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 01:43 am
If this has been covered let me know but,

Does anyone have an idea on what kind of extra wear the 4 tiles on the legs will have since they are supporting the weight of the capsule along with re-entry wear.  Are they just going to swap out the 4 tiles or can they make it through the 10 flights?

That's a good question, and I was wondering that myself.  I wouldn't be surprised to learn that those four small tiles get swapped out after every landing.  They're a very small portion of the heat shield, and since PICA-X has such a low density, I would think bearing the weight of the whole craft on landing would stand a good chance of rendering them unsuitable for another flight.  But I don't think any of us outside SpaceX and NASA actually know right now.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 06/02/2014 01:49 am
If this has been covered let me know but,

Does anyone have an idea on what kind of extra wear the 4 tiles on the legs will have since they are supporting the weight of the capsule along with re-entry wear.  Are they just going to swap out the 4 tiles or can they make it through the 10 flights?
Some time back I was asking about the attachment points of Dragon to the trunk. Apparently there was no heat shield on those four points. I would assume the Legs are on the other side of those four points.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 01:49 am

The basic principles don't care whether you've "worked on one".

I know enough to differentiate between the pressure wave, the expanding gas front, and the debris, and know how they're affected by altitude.

I know enough to know that engine bells can be dented pretty easily by flying debris.

I know that a dented engine bell will produce off-axis thrust, at best.

I know that if t/w is 0.25, you're only moving away from the exploding stage at, well, 0.25g.  If the engine bell is still ok. 


You don't know enough to know which basic principles matter.  An abort system that supplies over 10g's during upperstage flight is not needed.  All that is needed is a system that provides separation. It doesn't matter how far to get away.   Just getting away is enough.   There is no threat from debris, which was minor in the first place because upperstages don't blow up (show an upperstage that has blown up during ascent since the 80's).  Anyways, Apollo, CST-100, SNC have/had buffer between them and the upperstage, which negates the effects from debris.  Entry is happening no matter what, so the amount of distance from the stage don't matter.

Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?
"Upper staged don't explode".   Because they haven't?
If you're going to fly often, it's not crazy that one will.  All it takes is loss of control.

And I agree btw that resuming controlled flight is the most important task of the LAS.  It's just that without a LAS system, you're going to be hard-pressed achieving this with regular Dracos, or an Apollo SM that's just plain fragile compared with the SDs.

Besides, Jim, what exactly is your point?  SpaceX says they have LAS till orbit.  Given that there isn't a SM like in Apollo, what exactly are you arguing for?  Nevermind the against?

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 01:51 am

They got lucky and still experienced very high g's.

From entry and not the abort from the stage

From an entry that occurred after the uncontrolled separation (which you insists worked "as planned") twisted the capsule so the LAS fired downwards.  The excessive speed then in turn caused the re-entry conditions.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: sanman on 06/02/2014 01:56 am
Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?

I thought Boeing announced the pusher configuration for CST-100's LAS even before SpaceX ever made any similar announcement to the public.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: QuantumG on 06/02/2014 01:58 am
Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?

I thought Boeing announced the pusher configuration for CST-100's LAS even before SpaceX ever made any similar announcement to the public.

.. and the Orion pusher LAS predated both. An image of Mike Griffin's cocktail napkin is floating around somewhere.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 01:59 am
Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?

I thought Boeing announced the pusher configuration for CST-100's LAS even before SpaceX ever made any similar announcement to the public.

If so, then even better.  It means they thought it was a good idea.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mongo62 on 06/02/2014 02:03 am
Some time back I was asking about the attachment points of Dragon to the trunk. Apparently there was no heat shield on those four points. I would assume the Legs are on the other side of those four points.

My understanding is that one of the main advantages of a proper heat shield material like PICA and its derivatives is that they can withstand very high energy fluxes (usually by ablation) while still having a quite low mass, but that other materials can withstand the great heat but also require much greater mass to do the job (i.e. tungsten alloys).

So I would guess that the bases of the landing legs, instead of being covered by PICA-X, are covered with some denser but more mechanically sturdy material, since the extra mass required to use these materials for just those small areas, compared to using PICA-X, would be minimal.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/02/2014 02:09 am

They got lucky and still experienced very high g's.

From entry and not the abort from the stage

From entry after the uncontrolled separation (which you insists worked "as planned") twisted the capsule so the LAS fired downwards.  The excessive speed then in turn caused the re-entry conditions.
Arguing with Jim?
(http://img1.wikia.nocookie.net/__cb20120402225423/random-ness/images/3/34/Michael_Jackson_popcorn.gif)
;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Micahgtb on 06/02/2014 02:10 am
Some time back I was asking about the attachment points of Dragon to the trunk. Apparently there was no heat shield on those four points. I would assume the Legs are on the other side of those four points.

My understanding is that one of the main advantages of a proper heat shield material like PICA and its derivatives is that they can withstand very high energy fluxes (usually by ablation) while still having a quite low mass, but that other materials can withstand the great heat but also require much greater mass to do the job (i.e. tungsten alloys).

So I would guess that the bases of the landing legs, instead of being covered by PICA-X, are covered with some denser but more mechanically sturdy material, since the extra mass required to use these materials for just those small areas, compared to using PICA-X, would be minimal.

Makes sense.  (Not that you should) but do you know any HS materials that can support that load?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ArbitraryConstant on 06/02/2014 02:36 am
Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?
"Upper staged don't explode".   Because they haven't?
If you're going to fly often, it's not crazy that one will.  All it takes is loss of control.
I'm not sure that's true. A liquid rocket stage isn't an efficient explosive with premixed fuel and oxidizer that can detonate in the explosive sense (as opposed to a deflagration). It's not a gun, and when it wrecks itself it's not even a rocket anymore. I'm not sure what's going to provide sufficient acceleration to chase an escaping capsule.

Jim's making a lot of sense here.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 02:37 am

They got lucky and still experienced very high g's.

From entry and not the abort from the stage

From entry after the uncontrolled separation (which you insists worked "as planned") twisted the capsule so the LAS fired downwards.  The excessive speed then in turn caused the re-entry conditions.
Arguing with Jim?
(http://img1.wikia.nocookie.net/__cb20120402225423/random-ness/images/3/34/Michael_Jackson_popcorn.gif)
;)

Is the entertainment to your liking, Sire?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 02:43 am
Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?
"Upper staged don't explode".   Because they haven't?
If you're going to fly often, it's not crazy that one will.  All it takes is loss of control.
I'm not sure that's true. A liquid rocket stage isn't an efficient explosive with premixed fuel and oxidizer that can detonate in the explosive sense (as opposed to a deflagration). It's not a gun, and when it wrecks itself it's not even a rocket anymore. I'm not sure what's going to provide sufficient acceleration to chase an escaping capsule.

Jim's making a lot of sense here.


It's a bit funny, since wrt to LAS discussions, I've been making this exact same point - that the intent of a LAS is not to outrun an explosion, but to regain controlled flight and enable an emergency landing.

One of the main arguments I had was that yes, an exploding stage is not an efficiency detonation at all, and the capsule is actually pretty hardened, especially when looking at its back side.

But when considering an Apollo SM, which has a large soft nozzle sitting between it and the stage, and can only pull 0.25 g, it can get damaged and then it won't enable controlled flight.  At these velocities, if you can't fly straight, it's lethal.

This specific exchange started when Jim stated that SpaceX is misleading by saying that having the SD's abort to orbit is an advantage - since for example Apollo had this capability (via the SM), and besides, you don't need it.

So my question is simple.

- How can 8 redundant engines, protected behind the rim of the capsule not an improvement over one soft engine bell for a single engine?
- Given that no capsule today has a SM, how else are you going to achieve controlled flight, if you just jettisoned the LAS system?

What, in other words, is misleading with what SpaceX said?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 02:46 am
Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?
"Upper staged don't explode".   Because they haven't?
If you're going to fly often, it's not crazy that one will.  All it takes is loss of control.
I'm not sure that's true. A liquid rocket stage isn't an efficient explosive with premixed fuel and oxidizer that can detonate in the explosive sense (as opposed to a deflagration).

http://m.njit.edu/~muratov/hazards.pdf seems to disagree.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Nascent Ascent on 06/02/2014 03:37 am
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

Why would SpaceX care about a small number of critics on the internet?  The people evaluating the design at NASA are smart and knowledgeable enough to realize propulsive landing is a plus, not a minus.  As, I suspect, are most of the people on NSF.  Not all, but most.

I don't think SpaceX really cares, I suppose that wasn't my point. 

I just thought it surprising that Musk didn't mention launch escape, even in passing.  And then when people here claim that this new propulsive landing V2 design is such a major departure from V1 - I just found it interesting that no one really discussed one of the primary reasons for Super Dracos. Wasn't the lack of a launch escape capability one of the primary things needed to take people to ISS?

To me (and I'm a layman) it seems that V2 was an evolutionary design that provided launch escape and an alternative way of landing with greatly reduced costs.


Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: pathfinder_01 on 06/02/2014 03:42 am


Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?


CST-100 always planned for a pusher style LAS. The advantage of pusher style is twofold. One, at some point in the flight the puller style LAS must be released. It would interfere with reentry and probably block docking as well making it a risk to the mission and this risk happens on every mission. The other reason why is with a pusher style you could use the delta V that you would have used for escape for other purposes. With an puller style the mass of the LAS is wasted on every successful flight, but with puller style you could do something else with it.

Dragon V2 plans to land with it. CST-100 plans to re-boost the ISS with it. Dream Chaser plans to use the extra delta V to enable Dream Chaser to be able to extend its glide if need be.

Apollo, Soyuz and Mercury don’t use pusher style because pusher LAS systems are a lot less aerodynamic stable than puller style. Modern electronics is what makes the puller style possible (i.e.  Fly by wire).
Orion wanted to use pusher style but after spending money to develop it they found that it was too heavy for lunar missions. They would have needed to drag the extra mass of propellant to the moon and they could find no use for it within the Orion system so they switched back to puller style.

Using the mass to land propulsively is one heck of an ingenious solution. You gain pin point accuracy on landing.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 04:36 am
Ok got some DragonV2 images. Damn these guys work fast ..

Comes from this thread (http://forum.kerbalspaceprogram.com/threads/29388-LazTek-SpaceX-Launch-Pack-2-3-52-and-Exploration-Expansion-1-52-23-5-%285-7-14%29?p=1187924&viewfull=1#post1187924)

( Party thread, right ? )


Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 06/02/2014 04:44 am

Ok got some DragonV2 images. Damn these guys work fast ..

Comes from this thread (http://forum.kerbalspaceprogram.com/threads/29388-LazTek-SpaceX-Launch-Pack-2-3-52-and-Exploration-Expansion-1-52-23-5-%285-7-14%29?p=1187924&viewfull=1#post1187924)

( Party thread, right ? )

Nice, but the second image is not the Dragon v2 - the SD cowlings and trunk shows that it is based on the old mockup.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 06/02/2014 04:50 am
Ok got some DragonV2 images. Damn these guys work fast ..

Comes from this thread (http://forum.kerbalspaceprogram.com/threads/29388-LazTek-SpaceX-Launch-Pack-2-3-52-and-Exploration-Expansion-1-52-23-5-%285-7-14%29?p=1187924&viewfull=1#post1187924)

( Party thread, right ? )

Wrong trunk. This has the Dragon V1.3 (Musk's Q&A designation ) trunk with solar wing pods, not the Dragon V2 finned trunk with conformal solar arrays.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 04:54 am
Nice, but the second image is not the Dragon v2 - the SD cowlings and trunk shows that it is based on the old mockup.

Considering that the author seems to have posted a full "Dragon V2" flight profile video about two weeks ago i think that's forgivable ;) - click to the first page on that thread. Artistic license.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: OxCartMark on 06/02/2014 05:18 am
First post, just signed up.

I've been reading this thread as time allows since post 28, hoping to catch up but finding that the pace of adding new pages is nearly as fast as I'm finding time to read.  There are over the last few dozen pages only a few topics being discussed / debated and I think everyone including myself has an opinion and it looks like they won't be changing anytime soon.  So without further ceremony or delay I channel my inner Elon and offer the following architecture for your review and comment;

a) The Dragon trunk has so far been used for transporting cargo to and from ISS.  But the pallet system within it offers the opportunity for much more in non-ISS missions. The trunk, along with the reasonably large utility interconnection between the trunk and Dragon (quite visible in the V2 animation) allows for a high degree of quick mission specific configuring.  Pallets containing additional oxygen, batteries, CO2 scrubbing, hypergolics, hydrogen, fuel cells, fold out solar panels, a ~Canadarm, additional sewage tanks, a kestrel engine, radiation shield, etc. could be developed and the pallets loaded into the trunk and plumbed in as necessary.  In this manner the trunk would be the service module for the capsule.  This would allow much longer mission duration and capability.  Just as the Apollo CM had a short duration by itself and a much longer duration when coupled to the SM. With this the Dragon could I assume have the capability to drop into lunar orbit for an extended period of time, refuel / service satellites, do longer term research in orbit, do a more significant bit of orbital maneuvering, and possibly with a few more tricks and toys (Bigelow comes to mind) make it to Mars.  I wouldn't suggest that the hypergolic fuel could be transferred at anywhere near the flow rate to support SD combustion, but rather slowly so that after some heavy maneuvering the Dragon hypergolic tanks could be replenished for additional maneuvering or propulsive landing (forget I said those last two words, I don't want to add fuel to that discussion).  That would more or less be twist on the propellant cross feed theme SpaceX is already planning to use on Falcon Heavy.       Up to this point I've convinced myself this isn't unlikely, but now I venture into a bit of much less probable speculation - Lunar landing legs which deploy from a specialty pallet in the trunk.

b) I think its been established at least within this thread that the trunk aborts with the capsule, correct?  And cargo pallets are released from the trunk rearward (the only direction in which its open).  Does anyone have enough knowledge of the cargo mounting method to comment on whether it makes sense (and may have been planned all along) that at the moment an abort is initiated all trunk cargo would be unlatched and allowed to fall out the back (on rails?) to reduce mass and allow the empty trunk to perform its (assumed?) aerodynamic fin function??

Mark
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ArbitraryConstant on 06/02/2014 05:19 am
http://m.njit.edu/~muratov/hazards.pdf seems to disagree.
Which case in particular concerns you there in regards to upper stages?

There's cases like a cloud of aerosolized fuel managing to mix into a stoichiometric mixture before ignition, basically an accidental fuel air bomb, but the upper stage is in near vacuum...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 06/02/2014 05:34 am
The FUD is so deep here it's time for this party thread to get a mascot!

Be Vewy, Vewy, Afwaid!






Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 05:37 am
http://m.njit.edu/~muratov/hazards.pdf seems to disagree.
Which case in particular concerns you there in regards to upper stages?

There's cases like a cloud of aerosolized fuel managing to mix into a stoichiometric mixture before ignition, basically an accidental fuel air bomb, but the upper stage is in near vacuum...

When the paper says GOx they are usually talking about warmed LOx, not atmospheric GOx.

I'm not sure that's true. A liquid rocket stage isn't an efficient explosive with premixed fuel and oxidizer that can detonate in the explosive sense (as opposed to a deflagration).

As Figure 13 in the paper indicates, there exist conditions that can indeed create a high risk of a strong explosion (as opposed to a deflagration).  It depends on a number of factors, including how well the propellants are mixed and the presence of strong shocks or hot objects.

I'm not weighing in on whether strong explosions in upper stages or more or less likely than strong explosions in lower stages.  I'm just pointing out that research shows that they are possible given the right conditions.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: TripD on 06/02/2014 06:18 am
Did someone say party?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 06:35 am
Apollo, Soyuz and Mercury don’t use pusher style because pusher LAS systems are a lot less aerodynamic stable than puller style. Modern electronics is what makes the puller style possible (i.e.  Fly by wire).

You've been fooled by the Pendulum Fallacy.  Don't feel bad, Robert Goddard, a brilliant early rocket scientist, was fooled by it to.  He built his early rockets in a puller style because he believed it was more stable.  Eventually, people figured out that's not true.

http://en.wikipedia.org/wiki/Pendulum_rocket_fallacy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: docmordrid on 06/02/2014 06:40 am
I remember this guy at a UofM medical party, a totally target rich environment, who insisted on prattering on about biomedical engineering and stocks. Total bummer.

Mebbe the Discussion should be in the Discussion thread? Or maybe we need a FUD thread?

Just a thought guys, just a thought.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 06:49 am


Sigh.   If it doesn't matter, why did they carry that buffer?
Why did CST-100 switch to pusher LAS?  Just to be like SpaceX, or because they thought it was a good idea?


CST-100 always planned for a pusher style LAS. The advantage of pusher style is twofold. One, at some point in the flight the puller style LAS must be released. It would interfere with reentry and probably block docking as well making it a risk to the mission and this risk happens on every mission. The other reason why is with a pusher style you could use the delta V that you would have used for escape for other purposes. With an puller style the mass of the LAS is wasted on every successful flight, but with puller style you could do something else with it.

Dragon V2 plans to land with it. CST-100 plans to re-boost the ISS with it. Dream Chaser plans to use the extra delta V to enable Dream Chaser to be able to extend its glide if need be.

Apollo, Soyuz and Mercury don’t use pusher style because pusher LAS systems are a lot less aerodynamic stable than puller style. Modern electronics is what makes the puller style possible (i.e.  Fly by wire).
Orion wanted to use pusher style but after spending money to develop it they found that it was too heavy for lunar missions. They would have needed to drag the extra mass of propellant to the moon and they could find no use for it within the Orion system so they switched back to puller style.

Using the mass to land propulsively is one heck of an ingenious solution. You gain pin point accuracy on landing.

I agree that a pusher has many advantages, and some trade-offs, like having to carry the propellant to orbit. (Stability is not one of them, see above)

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".

SpaceX never claimed CST-100 doesn't have that capability.  They claimed that previous systems (e.g. Soyuz, Shuttle, Shenzhou, and to some degree Apollo) do not.

Anyhoo.

Was there ever an indication if Dragon LAS will always fire until out of fuel, or whether under some conditions will keep some propellant to help with landing?  Especially, I'm thinking, if the landing is over some random terrain far away?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 10:55 am
You know, in the sixties, people did some crazy stuff (flying around in capsules).  This entire commercial crew program is really an adventure in regressive psychology based on apparent successes with Apollo -v- Shuttle.  As we all know, the shuttle was cancelled primarily due to safety.  Is anything looking safer than shuttle?   To me v2 is looking worse.

OK, it's Garrett Reisman, so he's not an impartial observer, but:-

[So, compared to Shuttle, what do you think of the V2 here?] Oh, man, they're very, very different. [Oh, clearly, it's a totally different class of vehicle.] Yeah, totally different. The thing about V2 is, it has the potential to be a lot safer than shuttle. [You can abort at any time during flight, right?] Abort at any time, that's something the Shuttle couldn't do. You know, it's got very robust design for entry, it can sustain a number of failures and still be safe. The Shuttle was a wonderful, wonderful vehicle, but it was very... [fragile?] Fragile.

It operated very close to the edge of it's operating envelope.

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Prober on 06/02/2014 11:51 am
Some people are looking for the parachutes on Dragon v2 (were they included in the v2 design?  Donno?). 

There will be design changes from what we saw a couple days ago to what will eventually fly.
Parachutes included in v2, mentioned by Elon. V2 parachute drop test also completed.

No more significant design changes. Integrated critical design review completed in April. They're on the home stretch now.

huh?  where's the video on the  V2 parachute drop test ?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: rpapo on 06/02/2014 11:54 am
huh?  where's the video on the  V2 parachute drop test ?
NASA released the video a couple of months ago.  But that V2 was boilerplate, without the new shape and SD pods.  But it did have the new nose cap, which confused many people at the time.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: corrodedNut on 06/02/2014 11:55 am
huh?  where's the video on the  V2 parachute drop test ?
NASA released the video a couple of months ago.  But that V2 was boilerplate, without the new shape and SD pods.  But it did have the new nose cap, which confused many people at the time.

https://www.youtube.com/watch?v=Z6Kp6MMl0HQ
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 01:41 pm

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".


Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: inventodoc on 06/02/2014 02:01 pm
There seems to be a lot of discussion about spacecraft safety here.  Let me put this out.  What spacecraft would YOU rather fly or return to earth in?   

I certainly would not want to fly back in a Soyuz (despite its record).   Those things are always found in some field on its side looking like a burnt crisp - usually somewhere remote.  They are tiny and cramped.  The number of reentry problems a few years ago resulting in ballistic reentries weren't confidence inspiring either.'

I would rather return from orbit in a Dream Chaser (1st choice) followed by Dragon V2 followed by CST-100 or Orion before a Soyuz. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 02:51 pm

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".


Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights.

If the LAS is discarded shortly after S2 start, the upper stage would need a shorter burn to reach orbit, and would have greater margin in the event of a performance shortfall (something like the RL-10 issue some time ago, or the F1US that corkscrewed).

The balance of probabilities does seem to be that U/S under-performance is more likely than a catastrophic failure. If the under-performance comes after MECO, the first stage can't convert to expendable to make up the shortfall. (Maybe that's where prop reserved for a U/S recovery might come in useful.)

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 02:52 pm

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".


Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights.

So for the those of us that like having a plan B, it's an advantage.

Good to know you have such confidence in the hardware though.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 02:59 pm
Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights.

Jim, with all respect, the use of the absolute "don't blow up" is just inflaming the discussion.  I think a more sober statement would be something like, "the probability of blowing up late in flight is..." followed by some comparison to some larger risk condition which is/is not covered by the Dragon v2 design.

After all, if something makes the flight 0.01% safer without a downside, I think everyone would agree that is it a discriminator, however small ("irrelevant" is easy for someone not in the capsule to say).  But if it makes the flight safer in 0.01% of the flights but (say) adds risk to 2% of the flights, then we would all agree with your statement that it is just "hype" and not a "relevant discriminator".

We understand that you feel that upper stage failures are rare.  Since that's not the motivating rationale behind the Dragon V2's design (just a nice added bonus), Elon probably agrees with you.  (IIRC early on in SpaceX's history he commissioned a study of the causes of launch system failures, so he probably could cite computed probabilities for various upper stage failure modes.)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 02:59 pm

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".


Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights.

If the LAS is discarded shortly after S2 start, the upper stage would need a shorter burn to reach orbit, and would have greater margin in the event of a performance shortfall (something like the RL-10 issue some time ago, or the F1US that corkscrewed).

The balance of probabilities does seem to be that U/S under-performance is more likely than a catastrophic failure. If the under-performance comes after MECO, the first stage can't convert to expendable to make up the shortfall. (Maybe that's where prop reserved for a U/S recovery might come in useful.)

cheers, Martin

The LAS is not a last minute addition...  The trade between payload, propellant, and hardware mass is done holistically, when the system is designed.

So more likely, LAS to orbit means less payload, not reduced margin.

Oh, and you could use the LAS (throttled down) to escape to orbit....  It has lower ISP, but since you fire it post separation, it has more dV. (Compared with the stage 2 propellant you could have carried)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 03:02 pm

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".


Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights.

So for the those of us that like having a plan B, it's an advantage.


And the plan B is no better than previous plan B's using service modules.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 03:05 pm

Jim, with all respect, the use of the absolute "don't blow up" is just inflaming the discussion.
snip
We understand that you feel that upper stage failures are rare. 

snip

there is no feeling,  I dare you to find an upperstage failure late into burn.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 03:10 pm
Jim, with all respect, the use of the absolute "don't blow up" is just inflaming the discussion.  I think a more sober statement would be something like, "the probability of blowing up late in flight is..."
[...]
We understand that you feel that upper stage failures are rare. 
there is no feeling,  I dare you to find an upperstage failure late into burn.

Jim, certainly you're not saying, "because [something] has never happened before, it can never happen."

If it has not happened to date (and I'm not a space historian, so I'll leave that for others to research), you can claim "the probability is very low".  I have already cited published research showing it is not *impossible*.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AS-503 on 06/02/2014 03:14 pm
Given that most space craft that have windows fly with boost protective covers and are only used once, what durability should be expected of Dragon V2's big windows after several flights?

I wonder if V2 will fly with the windows *heads-down* (as much as possible) during ascent.

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Skyrocket on 06/02/2014 03:15 pm

Jim, with all respect, the use of the absolute "don't blow up" is just inflaming the discussion.
snip
We understand that you feel that upper stage failures are rare. 

snip

there is no feeling,  I dare you to find an upperstage failure late into burn.

One of the few, which might qualify for this, might be the Transtage failure on the OV2-1/LCS-2 launch of a Titan-IIIC on 15 Octber 1965. Although i'm not sure about the exact circumstances.

But anyway, it is a really rare type of incedent.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 03:48 pm
One of the few, which might qualify for this, might be the Transtage failure on the OV2-1/LCS-2 launch of a Titan-IIIC on 15 Octber 1965. Although i'm not sure about the exact circumstances.
Brief description of the LCS-2 failure: http://space.skyrocket.de/doc_sdat/lcs-1.htm

Note that http://www.nasaspaceflight.com/2014/05/russian-proton-m-launches-with-ekspress-am4r/ is also still on the NSF home page, which was an unspecified failure during third stage flight that resulted in loss of the satellite.

The Breeze-M upper stage has a long history of failures: https://en.wikipedia.org/wiki/Briz-M
We have little information about the exact failure for many of these, and what sort of acceleration would have been required to safely escape/abort.

Most upper-stage failures leave evidence which is rather difficult to examine.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 03:56 pm

Note that http://www.nasaspaceflight.com/2014/05/russian-proton-m-launches-with-ekspress-am4r/ is also still on the NSF home page, which was an unspecified failure during third stage flight that resulted in loss of the satellite.

The Breeze-M upper stage has a long history of failures: https://en.wikipedia.org/wiki/Briz-M
We have little information about the exact failure for many of these, and what sort of acceleration would have been required to safely escape/abort.

Most upper-stage failures leave evidence which is rather difficult to examine.

I am talking about US vehicles,  getting into LEO and explosions and not shutdowns. 
The point is that upperstages don't fail violently late into burns.

Apollo jettisoned its LES after the upperstage engine start event, when both the chance of failure and effects of failure were greatly reduced.  Even though the LES was gone, there still was a method to leave the vehicle, in case of other issues arising.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 04:06 pm
SSME has this nice old document called High Pressure Oxidizer Turbopump Explosions (http://www.enginehistory.org/SSME/SSME5_2.pdf).
It is not inconceivable that a newly developed engine with little flight heritage could run into similar teething issues, hopefully not in flight though.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 06/02/2014 04:10 pm
Exactly what is your point, Jim?

Do you think they *should* jettison the LAS - (if it was even possible) even though they designed it to be used for landing as well?

Other than "gosh Apollo did it this way so it must be good for all eternity", what point are you trying to make?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 04:11 pm

Jim - the core issues, again:

How does the SM, which has a large, fragile, flight-critical engine bell sitting right between itself and the exploding stage, and can only accelerate at 0.25 g, how does it get away from an exploding upper stage?

How are 8 high-power hypergolic engines, arranged in redundant pairs around and behind the heat shield, not superior to that?


It doesn't really need to.  Trick question.  It goes back engineering and common sense. 

The Apollo LES was jettisoned above the sensible atmosphere. 

Why?  Because the acceleration it provided was no longer needed. 
how come?  Blast/shock waves are reduced in a  ratified  atmosphere.

And the real reason, the upperstage can't really explode.  There is little to no oxygen to support combustion at these altitudes.  Since there are few volumes on the vehicle were fuel and oxidizer are in close proximity, such as the engine section, there is little opportunity or events that mix both propellants to allow any substantial explosion. 
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 04:13 pm

So what is "past the hype" then? Are you saying that keeping the LAS all the way to orbit is detrimental to the vehicle's overall reliability and abort chances? If not, then why does this argument even matter...

It is not an advantage over other systems that jettison an LAS and rely on other thrusters to provide the separation.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: bad_astra on 06/02/2014 04:22 pm
  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.

Name em.

blue Gemini: Hatches
x-33: Hatches
X-38: Hatches
X-37: hatches

Name a proposal that was not picked specifically or in part BECAUSE of hatches in the shield or quit making thought mcnuggets up.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 06/02/2014 04:32 pm
Why the discussion on hatches? Is there any evidence that there will be 'hatches' in the Dragon heat shield?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/02/2014 04:35 pm
  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.

Name em.

blue Gemini: Hatches
x-33: Hatches
X-38: Hatches
X-37: hatches

Name a proposal that was not picked specifically or in part BECAUSE of hatches in the shield or quit making thought mcnuggets up.

Did those missions have a similar thermal ride for the heatshield compared to a Dragon mission? But actually it isn't the hatches that bug me its how perfect those engines will have to fire to do an RTLS and then you have all the same issues with processing like shuttle. I'm talking the aspirational non-parachute landing of course. All of that to save some dough, hopefully.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 06/02/2014 04:37 pm

But having an abort capability even later in the flight is important, and a pusher such as configured on DV2 is a very robust way to provide that capability.   Better than "none at all", and better than "use a service module motor".


Quite wrong.   It is not that important to have that type of abort capability late into the flight.   Just another case of buying into the marketing hype and not real engineering.   It is not a relevant discriminator on any level.  Upperstages don't blow up late into flights.

So for the those of us that like having a plan B, it's an advantage.


And the plan B is no better than previous plan B's using service modules.

Except that this plan B also allows for a pinpoint propulsive landing.  I'd call that "better".
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 06/02/2014 04:43 pm

Jim - the core issues, again:

How does the SM, which has a large, fragile, flight-critical engine bell sitting right between itself and the exploding stage, and can only accelerate at 0.25 g, how does it get away from an exploding upper stage?

How are 8 high-power hypergolic engines, arranged in redundant pairs around and behind the heat shield, not superior to that?


It doesn't really need to.  Trick question.  It goes back engineering and common sense. 

The Apollo LES was jettisoned above the sensible atmosphere. 

Why?  Because the acceleration it provided was no longer needed. 
how come?  Blast/shock waves are reduced in a  ratified  atmosphere.

And the real reason, the upperstage can't really explode.  There is little to no oxygen to support combustion at these altitudes.  Since there are few volumes on the vehicle were fuel and oxidizer are in close proximity, such as the engine section, there is little opportunity or events that mix both propellants to allow any substantial explosion.

It's not just detonation that you have to worry about.  There are failure scenarios that could add unbalanced acceleration forces to part of the upper stage, potentially forcing the spacecraft sideways and sending it into a debris field.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 04:49 pm

It is clear that you didn't actually read the research report I cited earlier, so I'm not going to bother to continue this discussion further.  I suggest others similarly let this topic die, we are convincing no one and accomplishing nothing.

Where is the RP-1 tests?  Also,the tests weren't in a vacuum.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: DMeader on 06/02/2014 04:51 pm
I sorta wish we could get the refs to call "time" on the "LAS" and "hatches in heatshield" arguments. Neither is going anywhere.

Edit/Lar:  I am WAY behind on this thread and it is hardly a party thread with all the infighting. Well maybe one of those parties the Kappa Deltas used to throw where the cops came and broke up the fights.  But the KDs were hockey players. So ya, what did you expect. You guys are rocket scientists, or smart people who just happen not to be rocket scientists so what the heck?

Enough with the LAS and hatches. If I cut away every post that is too fighty and not enough party there would be about 30 pages less.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/02/2014 04:52 pm

It's not just detonation that you have to worry about.  There are failure scenarios that could add unbalanced acceleration forces to part of the upper stage, potentially forcing the spacecraft sideways and sending it into a debris field.

and why doesn't this matter?  Anyways
a.  there is  no unbalanced acceleration, the spacecraft separates
b.  and why would Dragon be better?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/02/2014 04:58 pm
Why the discussion on hatches? Is there any evidence that there will be 'hatches' in the Dragon heat shield?
Some people are worried that the landing legs compromise the integrity of the DV2 heat shield. Other people have pointed out that many designs have had hatches in the heat shield, or in the case of the shuttle (and DC) landing bay doors and as long as there is no path for the hot gas to flow through it's not an issue.  The counter argument seems to be everybody just got lucky and it's a really bad idea because...

It's a really tiresome debate.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/02/2014 05:07 pm
...
But actually it isn't the hatches that bug me its how perfect those engines will have to fire to do an RTLS and then you have all the same issues with processing like shuttle. I'm talking the aspirational non-parachute landing of course. All of that to save some dough, hopefully.
Saving dough is not a bad thing when your goal is to lower the cost of spaceflight.  From the NASA Commercial Crew Facebook Page (https://www.facebook.com/NASACommercialCrew/info):
Quote
The U.S. Government, through the National Aeronautics and Space Administration (NASA), is investing in the development of a U.S. commercial crew space transportation capability with the goal of achieving safe, reliable and cost effective access to and from low Earth orbit and the International Space Station (ISS).

Through this development and certification process, NASA will help lay the foundation for future commercial transportation capabilities, upon which commercial partners can market transportation services to the U.S. government and other customers. Once a transportation capability is certified for NASA use and services are available, NASA could purchase transportation services to meet its ISS crew rotation and emergency return obligations.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: tobi453 on 06/02/2014 05:09 pm
Nobody has talked about the chamber pressure of the SuperDraco yet! Musk says it has a pc of 1000 psi (~70 bar), which is very high for a pressure fed engine. The propellant tanks must therefore be at a pressure of ~100 bar (meaning they are going to be quite heavy)! A lot of Helium (meaning even more heavy tanks) is necessary to keep that pressure! ;)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 06/02/2014 05:19 pm
Who keeps adding "tags" to this thread? Stop it! Tags as for L2 threads only you cheeky monkey! ;D

So I've got about three articles to work out of Helo's video. I think this thread's not the best...."it's good, but it's not quite Carling" (UK beer advert, sorry about most of you not getting that).

When I get the next one on (which I think will be Garrett's comments), we'll have a look at a second thread, discussion - not party (as the latter was mainly for the event). Leave it with me.

For now, carry on.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 06/02/2014 05:20 pm
Why the discussion on hatches? Is there any evidence that there will be 'hatches' in the Dragon heat shield?
Some people are worried that the landing legs compromise the integrity of the DV2 heat shield. Other people have pointed out that many designs have had hatches in the heat shield, or in the case of the shuttle (and DC) landing bay doors and as long as there is no path for the hot gas to flow through it's not an issue.  The counter argument seems to be everybody just got lucky and it's a really bad idea because...

It's a really tiresome debate.
True but less tiresome than the current LAS to orbit is/is not necessary. :)
I think the the landing legs will be on the opposite sides of the Dragon Trunk attachment points therefore no hatches through the heat shield.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ncb1397 on 06/02/2014 05:25 pm
Nobody has talked about the chamber pressure of the SuperDraco yet! Musk says it has a pc of 1000 psi (~70 bar), which is very high for a pressure fed engine. The propellant tanks must therefore be at a pressure of ~100 bar (meaning they are going to be quite heavy)! A lot of Helium (meaning even more heavy tanks) is necessary to keep that pressure! ;)

They seem to have put a lot of effort into keeping the tank weight down given they are using carbon fiber reinforced titanium.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mvpel on 06/02/2014 05:31 pm

The propellant tanks must therefore be at a pressure of ~100 bar (meaning they are going to be quite heavy)! A lot of Helium (meaning even more heavy tanks) is necessary to keep that pressure! ;)
Elon said the COPV tank liners are made out of titanium - which is one of the nice things you can cost-justify if you're reusing the craft dozens of times instead of lscrapping it after one flight.  This article looks interesting:

http://arc.aiaa.org/doi/abs/10.2514/6.1996-2751
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: uhuznaa on 06/02/2014 05:33 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA

It wouldn't make any sense though. If your objectives are having a launch escape system, assuring safe landings and maximal payloads you'd never come up with a pusher-style liquid fueled system. You'd use a puller-style solids tower and then a parachute landing over water, period. And then you'd never would do propulsive landings.



Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: yg1968 on 06/02/2014 05:36 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the hole where the Dragon V2 legs come out in order to add safety to their design.

Secondly, I noticed that the exterior of the Super Dracos is now black. Does that mean that a Pica-X shield is being used to protect them during re-entry?

Edit: clarification.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/02/2014 05:38 pm
...
But actually it isn't the hatches that bug me its how perfect those engines will have to fire to do an RTLS and then you have all the same issues with processing like shuttle. I'm talking the aspirational non-parachute landing of course. All of that to save some dough, hopefully.
Saving dough is not a bad thing when your goal is to lower the cost of spaceflight.  From the NASA Commercial Crew Facebook Page (https://www.facebook.com/NASACommercialCrew/info):
Quote
The U.S. Government, through the National Aeronautics and Space Administration (NASA), is investing in the development of a U.S. commercial crew space transportation capability with the goal of achieving safe, reliable and cost effective access to and from low Earth orbit and the International Space Station (ISS).

Through this development and certification process, NASA will help lay the foundation for future commercial transportation capabilities, upon which commercial partners can market transportation services to the U.S. government and other customers. Once a transportation capability is certified for NASA use and services are available, NASA could purchase transportation services to meet its ISS crew rotation and emergency return obligations.


Safety first. Will be same for tourists or colonists, who cares about the USG isn't this a SpaceX thread?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 05:40 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the Dragon V2 legs in order to add safety to their design.
That makes no sense. One might as well suggest coating the astronauts in asbestos.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 06/02/2014 05:45 pm
At the end of the day, the funding happens because there is public and congressional support for it.
In my opinion, Elon Musk and his crew have a lot better chance of building public support and NASA funding via their exciting strategy.

CST-100 and Dream Chaser don't seem to inspire anyone to care except the contractors getting the paychecks.

...And here is where you miss the entire point of how GOVERNMENT funding operates my freind! :)

Funding happens because of ONE reason and one reason only and that is political interest(s) involved. The "public" support or lack thereof has little effect on those involved as, (specifically where "space" funding is involved) because not enough people use "space funding" as a criteria for either funding campaigns or voting. "Special Interest" which may include certain targeted sectors of the "public" and/or corporations or business' are the factions that matter in this case. (And in this "fashion" SpaceX is almost oup there with Boeing and LM for having a politicians ear)

The "problem" with CC is there is a divided "opinion/support" in Congress itself over it with some members supporting and others opposing. The "majority" however seem opposed and have been trying in various and sundry ways to "kill" the program in favor of continueing to provide ALL services through NASA. (There has been some 'wavering' since the latest crisis with Russia as looking "soft" in that direction is a "big-deal" to most of the constiuants in the space districts)

The current "favorite" idea if this can not be done is either to pick a concept with a "deep historical and technical expertise and proven safety background" (read CST-100) or possibly a concept which is at a low technilogical and/or operational status which can be delayed until such a time as it can be declared a "failure" and the program scrubbed.

I'm very much afraid, (in the "gleefully looking forward too" type) that Congress will, has in fact, dug itself a bit of a hole they can't get out of. As observed for the last 40+ years Congress has focused on paying less and less for actual hardware and more towards targeted funding of "earth-based" programs where the little or no "space" progress is made but a good deal of funds and resources are spread around here on Earth. The main "aim" has seemed to have been to give the impression that the US Space program is "doing-something" while doing (and paying) as little as possible.

But I belive they have painted themselves into a corner by trying to appear to "support" civil space in ways that have now become a hinderence to them and they are now finding that it will not be easy to "sweep-aside" the changes without reprecusions.

RAndy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 06/02/2014 05:50 pm
No one knows the history of SpaceX's ideas and iterations of their human rated capsules, but I would think, they had powered landing on their minds long before, NASA demanded some LAS. EM has said they would take more risk if NASA was not their customer [citation not needed]. So the system they have now, if it works, is a great solution. It seems unlikely they could have, the tried and true LES system, with their powered lander. That is my gist of it anyway.

The questions that matter: Is DV2 safer than anything currently in flying, Soyuz? Is is safer than the Shuttle? Is it safer than the so called competition?  Is it cheaper than the competition? Does it have more capability than the competition? How DV2 gets there is irrelevant.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: yg1968 on 06/02/2014 05:55 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the Dragon V2 legs in order to add safety to their design.
That makes no sense. One might as well suggest coating the astronauts in asbestos.

It was a question. Not a statement. Your response is rude and uninformative. If it makes no sense to do that, I would have appreciated knowing why it makes no sense.

Incidentally, I should have been clearer. I meant to add Pica-X shielding to the interior of the hole where the legs come out (not the legs themselves). I have edited my initial post to clarify this.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 06:11 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the Dragon V2 legs in order to add safety to their design.
That makes no sense. One might as well suggest coating the astronauts in asbestos.

It was a question. Not a statement. Your response is rude and uninformative. If it makes no sense to do that, I would have appreciated knowing why it makes no sense.

Incidentally, I should have been clearer. I meant to add Pica-X shielding to the interior of the hole where the legs come out (not the legs themselves).

The landing leg foot, sitting in its recess, creates a labyrinth that resists gas inflow. I'm guessing also a high temperature seal - though no seal can take the full temperature of the outside plasma.

It makes sense that the recess itself be made of a high-temperature ceramic, since if you get a little bit of hot gas in there, you don't want it to erode itself a large flow path.

If that's what you were thinking by saying "inside", then yes, it makes sense.

As for rudeness, people here often confuse being dismissive and rude with being knowledgeable.  Don't worry about it.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 06/02/2014 06:12 pm
More amazing people excuse making and dismissing of risk.

Ike, you ARE aware that NASA as well as the Air Force proved to their satisfaction that "hatches" in a heat-sheild are in fact NOT a "big-deal" to either maintain or use? That the latter in fact cut a DOOR AND HATCH into the heat sheild of a Gemini spacecraft to TEST this extensivly? No problems. No issues.

NASA itself has extensivly studied various methods of "propulsive" landing and in general they have found only ONE issue with the procedure:
It is NOT "cost-effective" for a limited number of "missions" with non-reusable manned vehicles.

Mercury, Gemini, and Apollo were all expendable vehicles flying "few" actual missions. The Shuttle was concieved from the start as a "winged-flyback-horizontal landing vehicle. Though "offered" by various designs and contractors "powered" flight and "vertical landing" were both rejected early on for political and design compromise reaons.

It is NOT that NASA has not considered it and "rejected" it on any safety, operational, or really "financial" basis. It is simply that NASA has never had a program that me the criteria to make "propulsive" landing an viable option for them. Just because NASA did no USE a particular technology in no way invalidates that technology on that basis alone. NASA studied concepts and ideas they KNEW the could never use for one reason or another, that did not stop them from studying and finding that there were good solid reasons those systems COULD be used with the right requirements.

Before you assume that NASA "rejected" an idea it might be well to look around and see if NASA had done any work on or with the idea before you declare thier "stand" on an issue.

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: llanitedave on 06/02/2014 06:17 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the Dragon V2 legs in order to add safety to their design.
That makes no sense. One might as well suggest coating the astronauts in asbestos.

It was a question. Not a statement. Your response is rude and uninformative. If it makes no sense to do that, I would have appreciated knowing why it makes no sense.

Incidentally, I should have been clearer. I meant to add Pica-X shielding to the interior of the hole where the legs come out (not the legs themselves).

The landing leg foot, sitting in its recess, creates a labyrinth that resists gas inflow. I'm guessing also a high temperature seal - though no seal can take the full temperature of the outside plasma.

It makes sense that the recess itself be made of a high-temperature ceramic, since if you get a little bit of hot gas in there, you don't want it to erode itself a large flow path.

If that's what you were thinking by saying "inside", then yes, it makes sense.

As for rudeness, people here often confuse being dismissive and rude with being knowledgeable.  Don't worry about it.

Looking at the footpads themselves, they are thick and black, so I was assuming that the heat protective material extended a good way up into the well anyway.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 06/02/2014 06:18 pm
My point is just that parachutes do not allow "pinpoint guidance" -- which is especially important in abort situations (as in the linked Soyuz example).

Before you make a statement you might want to "google" it first:
http://www.atair.com/
http://www.popularmechanics.com/technology/military/4257762
http://www.airborne-sys.com/pages/view/us-army-selects-dragonfly-and-firefly-self-guided-

"Guided" parachutes have been available both commercially and otherwise for a number of years, so "yes" in fact parachutes DO allow for "pinpoint guidance."

The main reason no SPACE PROGRAM generally uses them is because the control and actuator systems to control the parachutes are more difficlt to build into a design but it HAS been done. The X-38 demonstrator used a guided parafoil for low speed flight and landing.


Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 06:22 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA

It wouldn't make any sense though. If your objectives are having a launch escape system, assuring safe landings and maximal payloads you'd never come up with a pusher-style liquid fueled system. You'd use a puller-style solids tower and then a parachute landing over water, period. And then you'd never would do propulsive landings.

Why do you believe that to be true?  What's your evidence?

Many posts on this thread have pointed out the safety advantages of propulsive landing with a parachute backup.  Have you read them?  If you disagree, why?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 06:25 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the Dragon V2 legs in order to add safety to their design.
That makes no sense. One might as well suggest coating the astronauts in asbestos.

It was a question. Not a statement. Your response is rude and uninformative. If it makes no sense to do that, I would have appreciated knowing why it makes no sense.

Yes , sorry, i understand this came across completely uninformative.

A lot of these "safety enhancement" suggestions do not make any sense for the same reason that they are not passing out parachutes for all passengers on any commercial airlines.

While there is theoretical, minuscule corner case where there might be a disaster scenario where this would help save a life - this is not done because it adds multiple layers of really bad day failure scenarios, and all effort is better spent on avoiding such disaster in the first place.

But i'm sure that CareBear & Associates will disagree.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 06:26 pm
My point is just that parachutes do not allow "pinpoint guidance" -- which is especially important in abort situations (as in the linked Soyuz example).

Before you make a statement you might want to "google" it first:
http://www.atair.com/
http://www.popularmechanics.com/technology/military/4257762
http://www.airborne-sys.com/pages/view/us-army-selects-dragonfly-and-firefly-self-guided-

"Guided" parachutes have been available both commercially and otherwise for a number of years, so "yes" in fact parachutes DO allow for "pinpoint guidance."

The main reason no SPACE PROGRAM generally uses them is because the control and actuator systems to control the parachutes are more difficlt to build into a design but it HAS been done. The X-38 demonstrator used a guided parafoil for low speed flight and landing.

Randy

X-38 was a lifting body with a parafoil.  Of course it had more control over it landed than a capsule coming down under parachutes.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 06:27 pm
  Yes, hatches in heatshields has been done. But NASA has recognized it as a vulnerability in any craft and shyed awy from numerous designs that relied on hatch openings aft for just this reason.

Name em.

blue Gemini: Hatches
x-33: Hatches
X-38: Hatches
X-37: hatches

Name a proposal that was not picked specifically or in part BECAUSE of hatches in the shield or quit making thought mcnuggets up.

Did those missions have a similar thermal ride for the heatshield compared to a Dragon mission?

That's irrelevant.  The claim was the any opening in a heat shield was a vulnerability that NASA just wouldn't tolerate.

But actually it isn't the hatches that bug me its how perfect those engines will have to fire to do an RTLS

The engines don't have to fire perfectly.  They can lose an engine and be fine.

If you're talking about fine control of thrust, you'll see as soon as DragonFly starts flying that that's no problem.

and then you have all the same issues with processing like shuttle. I'm talking the aspirational non-parachute landing of course. All of that to save some dough, hopefully.

Non-parachute landings aren't aspirational.  They're plan A and there's no real reason to think they won't work.  We'll see in less than a year when DragonFly starts making them.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: mme on 06/02/2014 06:36 pm
...
Safety first. Will be same for tourists or colonists, who cares about the USG isn't this a SpaceX thread?
SpaceX is trying to win a commercial crew contract, so they care about NASA and the goals of the Commercial Crew program.  Seems relevant to me.

So you don't like hypergolic propulsive landing, what do you prefer? Wings, parachutes, non-hypergolic propulsive landing? What's the "right" design?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space OurSoul on 06/02/2014 06:36 pm
Thanks for the data on holes-in-heatshields, Randy. I didn't know about all that early work. Quite reassuring :-).

Do folks think it's important that none of the previous hatches were:

1) subjected to indirect rocket exhaust while open (and exhaust-driven FOD as opposed to FOs merely thrown up by the landing gear)
2) actually attached to the structural members that take landing stresses and thus more likely to suffer alignment issues when closed again

Would we expect SpaceX to have a protocol to detect any small leaks on the ground before re-launch? (Like testing if the leg cavity can hold a vacuum while the leg is retracted?)

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: RanulfC on 06/02/2014 06:37 pm

Secondly because "propulsive-flight-control" (focusing on the whole flight envelope rather than any one "phase" here) is by its nature a safer, more reliable system from end-to-end. Why? Parachutes and wing (lifting) flight both have unavoidable "dead-zones" where they will not function properly. Specifically they have an altitude and minimum-speed requirement respectivly below which they can't function. Propulsive is a "zero-to-maximum" system at any point. If it works at all, as long as it has propellant there are no "dead-zone" restrictions

Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.

Ok, you get a half a point for DC but I'll point out it has the SAME "dead-zone" as any other lifting vehicle if it DOES NOT REACH SUFFICENT SPEED TO BE ABLE TO ACHIEVE LIFT :)

More Specifically the DC is planning on using hybrids which can still "fail" during run which can lead to being in the "dead" zone for lift with no power available.

So you get a half point for pointing out that DC has its own "intergral" propulsion the same as the D-V2, but that still doesn't "negate" the point that DC has a minium "speed" target it has to get to in order to "fly"

Randy
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 06:38 pm
So you don't like hypergolic propulsive landing, what do you prefer? Wings, parachutes, non-hypergolic propulsive landing? What's the "right" design?

There is only One True Way.

https://www.youtube.com/watch?v=7Kp63-an2ts
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 06:39 pm
My point is just that parachutes do not allow "pinpoint guidance" -- which is especially important in abort situations (as in the linked Soyuz example).
"Guided" parachutes have been available both commercially and otherwise for a number of years, so "yes" in fact parachutes DO allow for "pinpoint guidance."
I am well aware of that.  (Although your pins have considerably larger points than mine.)

The main reason no SPACE PROGRAM generally uses them is because the control and actuator systems to control the parachutes are more difficult to build into a design.

You're making my point.  I was just pointing out that guidance was useful in abort situations -- useful enough to justify some added complexity (as in the X-38 program).

(If others are interested, http://spaceflight.nasa.gov/history/station/x38/newtech.html and http://spaceflight.nasa.gov/history/station/x38/parafoil.html have some more details on the X-38 parafoil.)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Sean Lynch on 06/02/2014 06:52 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the hole where the Dragon V2 legs come out in order to add safety to their design.

Secondly, I noticed that the exterior of the Super Dracos is now black. Does that mean that a Pica-X shield is being used to protect them during re-entry?

Edit: clarification.

The pad mating surfaces are at an angle \V/ such that the more pressure that is applied, the tighter the "plug"
(or landing pad) is pressed against the mating surface.  A gross over simplification perhaps, but no need to worry about the leg or leaks.  If you've watched many spacewalks, especially the Chinese walk, you'll see just how tightly a tiny bit of pressure can maintain a very strong seal.
w/r to black features, very well could  be thermal protection. Leading edges and surfaces exposed directly to the "wind" during reentry are the areas of highest dynamic pressure during reentry.
hth
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 06:57 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA

It wouldn't make any sense though. If your objectives are having a launch escape system, assuring safe landings and maximal payloads you'd never come up with a pusher-style liquid fueled system. You'd use a puller-style solids tower and then a parachute landing over water, period. And then you'd never would do propulsive landings.

Why do you believe that to be true?  What's your evidence?

Many posts on this thread have pointed out the safety advantages of propulsive landing with a parachute backup.  Have you read them?  If you disagree, why?

Consider an alternative universe where Dragon v2 dumps the LAS prop once at the point where Apollo did / Orion will jettison its solid. IE makes the same safety assumptions as those, and relies on the parachutes (that you're carrying anyway) for the landing

By dumping mass during the ascent, the launcher can lift more to orbit, IE the "...and maximal payloads..." clause of the statement.



However, I fall into the camp that thinks the practical benefits of the land landing are worth the loss of payload, and I do like the concept that the LAS prop can fire as third stage to perform an abort-to-orbit, relying on the parachutes for the landing. Nice extra margin at the expense of probably not reusing the capsule again after a water landing.

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: OSE on 06/02/2014 06:59 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the hole where the Dragon V2 legs come out in order to add safety to their design.

Secondly, I noticed that the exterior of the Super Dracos is now black. Does that mean that a Pica-X shield is being used to protect them during re-entry?

Edit: clarification.

The pad mating surfaces are at an angle \V/ such that the more pressure that is applied, the tighter the "plug"
(or landing pad) is pressed against the mating surface.  A gross over simplification perhaps, but no need to worry about the leg or leaks.  If you've watched many spacewalks, especially the Chinese walk, you'll see just how tightly a tiny bit of pressure can maintain a very strong seal.
w/r to black features, very well could  be thermal protection. Leading edges and surfaces exposed directly to the "wind" during reentry are the areas of highest dynamic pressure during reentry.
hth

Small nitpick:
The leading edges have high heating loads because they are exposed to stagnation conditions and thin boundary layers.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/02/2014 07:00 pm
Secondly, I noticed that the exterior of the Super Dracos is now black. Does that mean that a Pica-X shield is being used to protect them during re-entry?
w/r to black features, very well could  be thermal protection. Leading edges and surfaces exposed directly to the "wind" during reentry are the areas of highest dynamic pressure during reentry.

I assumed that the thermal protection was at least partly due to the fact that those surfaces will be directly exposed to the SuperDraco exhaust when they are firing.  That might be an additional reason for thermal protection in the area below the SuperDraco engine bells.  It's reasonable to suppose that the Pica-X material is used everywhere Dragon v2 is black -- but that might not be 100% true.  As has been noted earlier, the Pica-X material is very low-density, so the footpads are almost certainly *not* Pica-X.  It's possible the area below the SuperDraco is also some other heat shield material -- perhaps one which better resists hot rocket exhaust.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ncb1397 on 06/02/2014 07:14 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA

It wouldn't make any sense though. If your objectives are having a launch escape system, assuring safe landings and maximal payloads you'd never come up with a pusher-style liquid fueled system. You'd use a puller-style solids tower and then a parachute landing over water, period. And then you'd never would do propulsive landings.

Why do you believe that to be true?  What's your evidence?

Many posts on this thread have pointed out the safety advantages of propulsive landing with a parachute backup.  Have you read them?  If you disagree, why?

Consider an alternative universe where Dragon v2 dumps the LAS prop once at the point where Apollo did / Orion will jettison its solid. IE makes the same safety assumptions as those, and relies on the parachutes (that you're carrying anyway) for the landing

By dumping mass during the ascent, the launcher can lift more to orbit, IE the "...and maximal payloads..." clause of the statement.


I disagree. You don't maximize payload to orbit by throwing rocket propellant away(solid or otherwise). You maximize payload to orbit by using rocket propellant. If there was ever a need for heavier lift, presumeably you can fire the super-dracos to enable that in which case the LAS propellant is hardly dead weight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: savuporo on 06/02/2014 07:21 pm
I disagree. You don't maximize payload to orbit by throwing rocket propellant away(solid or otherwise). You maximize payload to orbit by using rocket propellant. If there was ever a need for heavier lift, presumeably you can fire the super-dracos to enable that in which case the LAS propellant is hardly dead weight.
Okay, just for clarity, once again.

For a manned spacecraft payload to orbit is absolutely not a the top of the design criteria, whereas for a launch vehicle, or a heavy launch vehicle it is.

For manned spacecraft, you want to make the ride comfortable, provide reasonable redundancies so you can still save the crew even when sacrificing the vehicle and so on.

For a dump truck to orbit, i.e. something that is designed to lift low value goods, yes you want to maximise payload.

For something that is designed to launch national security payloads, you optimize for different variables like making sure it actually gets there, and if it doesn't it is blown up to as tiny pieces as possible.

Different vehicles, different uses, different goals. Not a too novel concept.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: jeff.findley on 06/02/2014 07:22 pm

Jim - the core issues, again:

How does the SM, which has a large, fragile, flight-critical engine bell sitting right between itself and the exploding stage, and can only accelerate at 0.25 g, how does it get away from an exploding upper stage?

How are 8 high-power hypergolic engines, arranged in redundant pairs around and behind the heat shield, not superior to that?


It doesn't really need to.  Trick question.  It goes back engineering and common sense. 

The Apollo LES was jettisoned above the sensible atmosphere. 

Why?  Because the acceleration it provided was no longer needed. 
how come?  Blast/shock waves are reduced in a  ratified  atmosphere.

And the real reason, the upperstage can't really explode.  There is little to no oxygen to support combustion at these altitudes.  Since there are few volumes on the vehicle were fuel and oxidizer are in close proximity, such as the engine section, there is little opportunity or events that mix both propellants to allow any substantial explosion. 


I think you're missing the forest for the trees.  Apollo's LES was jettisoned as soon as it was practical because the longer it stayed on top of the stack, the more it negatively impacted the performance of the launch vehicle (i.e. reduced payload).  Since everything on Apollo/Saturn was expendable, the design approach was the traditional "performance uber alles" used previously to design missiles and ICBMs.

Dragon V2's liquid fueled launch escape system makes it possible to use the launch escape system's "leftover" fuel for something else that's deemed useful.  If your goal is to reduce overall operations costs by reusing your capsules, a soft landing that isn't in corrosive salt water is desired.  Propulsive landing in the case of a nominal mission using "leftover" fuel seems quite reasonable to me.  Transitioning from expendable hardware to sanely reusable hardware means you simply can't keep doing things the same way they were done during Apollo/Saturn, which was cancelled not because of any shortage of future applications, but because it was seen as far too expensive to maintain.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 07:31 pm
I apologize if this is a dumb question. But in order to reduce risks, could SpaceX add some Pica-X shielding in the interior of the hole where the Dragon V2 legs come out in order to add safety to their design.

Secondly, I noticed that the exterior of the Super Dracos is now black. Does that mean that a Pica-X shield is being used to protect them during re-entry?

Edit: clarification.

The pad mating surfaces are at an angle \V/ such that the more pressure that is applied, the tighter the "plug"
(or landing pad) is pressed against the mating surface.  A gross over simplification perhaps, but no need to worry about the leg or leaks.  If you've watched many spacewalks, especially the Chinese walk, you'll see just how tightly a tiny bit of pressure can maintain a very strong seal.
w/r to black features, very well could  be thermal protection. Leading edges and surfaces exposed directly to the "wind" during reentry are the areas of highest dynamic pressure during reentry.
hth

Elon quoted during the Q&A that PICA-X v3 can take record-breaking heat loads. The penetrations will need to be sealed to a similar standard, while still allowing the seal to be broken to deploy the legs.

Ironically, the worst sort of bad day would be a Challenger-type fault (failed seal allowing hot gasses to pass) and Columbia-type consequence (heatshield failure during reentry).

Comes down to engineering of the seal. I'll be interested to find out how they're planning to manage that.

cheers, Martin

PS I seem to be making a lot of negative-sounding posts about SpaceX recently. I don't have any sort of downer, just pointing out issues that I'm sure they can deal with.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: NovaSilisko on 06/02/2014 07:32 pm

There is only One True Way.

You know, I never realized until now that Roton had a very similar leg mechanism to F9R... The more you know
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lars_J on 06/02/2014 07:39 pm
Elon quoted during the Q&A that PICA-X v3 can take record-breaking heat loads. The penetrations will need to be sealed to a similar standard, while still allowing the seal to be broken to deploy the legs.

Ironically, the worst sort of bad day would be a Challenger-type fault (failed seal allowing hot gasses to pass) and Columbia-type consequence (heatshield failure during reentry).

Comes down to engineering of the seal. I'll be interested to find out how they're planning to manage that.

Keep in mind that every Dragon flown so far have had six (yes 6) holes in the PICA-X heat shield. One hole for each of the structural trunk attachment point. (see pictures, one before and one after flight)

So I don't think we need to be excessively worried about a "failed seal" in the heat shield. They have experience with the material, and flight experience to boot.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 07:44 pm
Somehow I suspect that if SpaceX and Elon pitched Dragon V2 as...

We now have a launch escape system and we're almost ready for manned flights...and in the future we will consider propulsive landings...

...it would have been received much better by the critics.

-NA

It wouldn't make any sense though. If your objectives are having a launch escape system, assuring safe landings and maximal payloads you'd never come up with a pusher-style liquid fueled system. You'd use a puller-style solids tower and then a parachute landing over water, period. And then you'd never would do propulsive landings.

Why do you believe that to be true?  What's your evidence?

Many posts on this thread have pointed out the safety advantages of propulsive landing with a parachute backup.  Have you read them?  If you disagree, why?

Consider an alternative universe where Dragon v2 dumps the LAS prop once at the point where Apollo did / Orion will jettison its solid. IE makes the same safety assumptions as those, and relies on the parachutes (that you're carrying anyway) for the landing

By dumping mass during the ascent, the launcher can lift more to orbit, IE the "...and maximal payloads..." clause of the statement.


I disagree. You don't maximize payload to orbit by throwing rocket propellant away(solid or otherwise). You maximize payload to orbit by using rocket propellant. If there was ever a need for heavier lift, presumeably you can fire the super-dracos to enable that in which case the LAS propellant is hardly dead weight.

Same difference. Dump it and maximise performance of the upper stage. Retain it, and burn it as third stage. Either way, you're disposing of the LAS prop once you're not going to fire the LAS, and increasing payload at the expense of needing to use the parachutes to land

But, as I say, I am persuaded by the argument that a propulsive landing has benefits worth the loss of ultimate payload to orbit, while adding margin if you're prepared to burn the prop for abort to orbit and land under parachutes. Its another nice trade to le them abandon reuse to increase margin.

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: HMXHMX on 06/02/2014 07:49 pm
So you don't like hypergolic propulsive landing, what do you prefer? Wings, parachutes, non-hypergolic propulsive landing? What's the "right" design?

There is only One True Way.

https://www.youtube.com/watch?v=7Kp63-an2ts

Hey, my Chief Engineer had a thing for spinning stuff….  :)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: GalacticIntruder on 06/02/2014 07:58 pm
Just for some clarifications:

Musk stated PICA-X gen 3 heating rate is roughly 1000W/CM^2. It is secret, so I don't expect actual numbers. But if the Wiki entry is correct, the original NASA PICA is 1200W/CM^2.

Not that it matters too much, unless DV2 is expected to return from BEO, like Stardust did, and Orion is supposed to do.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Helodriver on 06/02/2014 08:02 pm
Just uploaded a few minutes of new video from the Dragon V2 reveal event.  The first part is a general view of the scene before the unveiling with some views of Dragon 1 hanging overhead. More interesting is the few minutes of hardware closeups obtained before being shooed off the platform. Similar to the stills I already dumped, there are some good views of the TPS, Dracos, Superdracos, Main hatch mechanism and umbilical panel.

https://www.youtube.com/watch?v=nsnQyZCrjsM&feature=youtu.be (https://www.youtube.com/watch?v=nsnQyZCrjsM&feature=youtu.be)
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: meekGee on 06/02/2014 08:06 pm
Just for some clarifications:

Musk stated PICA-X gen 3 heating rate is roughly 1000W/CM^2. It is secret, so I don't expect actual numbers. But if the Wiki entry is correct, the original NASA PICA is 1200W/CM^2.

Not that it matters too much, unless DV2 is expected to return from BEO, like Stardust did, and Orion is supposed to do.

I somehow recall that normal reentry heat load is 100 W/cm2 (which in my little world translates to "1000 suns"), and the new stuff can go 10x that.

But I may have dropped or found a zero along the way..
.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 08:27 pm
Just uploaded a few minutes of new video from the Dragon V2 reveal event.  The first part is a general view of the scene before the unveiling with some views of Dragon 1 hanging overhead. More interesting is the few minutes of hardware closeups obtained before being shooed off the platform. Similar to the stills I already dumped, there are some good views of the TPS, Dracos, Superdracos, Main hatch mechanism and umbilical panel.

https://www.youtube.com/watch?v=nsnQyZCrjsM&feature=youtu.be (https://www.youtube.com/watch?v=nsnQyZCrjsM&feature=youtu.be)

I'm guessing the SuperDracos were not fitted into their ports, since it looks like there was light showing through from where the thrust chamber should be?

cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 06/02/2014 08:51 pm
I'm guessing the SuperDracos were not fitted into their ports, since it looks like there was light showing through from where the thrust chamber should be?


It doesn't look like light showing through but something shiny being illuminated by the camera light. The pintle would be a good guess.

But check out the hatch, those four cams lock it? Compare to Apollo hatch latch array...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Helodriver on 06/02/2014 08:58 pm
I'm guessing the SuperDracos were not fitted into their ports, since it looks like there was light showing through from where the thrust chamber should be?


It doesn't look like light showing through but something shiny being illuminated by the camera light. The pintle would be a good guess.

But check out the hatch, those four cams lock it? Compare to Apollo hatch latch array...


The inside of the engine bells was silver metal, lit by the white light coming up from the illuminated platform floor below.

I expected the hatch to have a more extensive locking mechanism as well.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: JBF on 06/02/2014 08:59 pm
I'm guessing the SuperDracos were not fitted into their ports, since it looks like there was light showing through from where the thrust chamber should be?


It doesn't look like light showing through but something shiny being illuminated by the camera light. The pintle would be a good guess.

But check out the hatch, those four cams lock it? Compare to Apollo hatch latch array...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mongo62 on 06/02/2014 08:59 pm
Just for some clarifications:

Musk stated PICA-X gen 3 heating rate is roughly 1000W/CM^2. It is secret, so I don't expect actual numbers. But if the Wiki entry is correct, the original NASA PICA is 1200W/CM^2.

Not that it matters too much, unless DV2 is expected to return from BEO, like Stardust did, and Orion is supposed to do.

Elon says that the material "can handle over a kilowatt per square centimeter", so it's somewhere north of 1000 W/cm^2. He also says that the material can handle twice the kinetic energy it will be exposed to (presumably during LEO reentry, since he mentions Mach 25, which was STS reentry speed).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: oiorionsbelt on 06/02/2014 09:11 pm

Keep in mind that every Dragon flown so far have had six (yes 6) holes in the PICA-X heat shield. One hole for each of the structural trunk attachment point. (see pictures, one before and one after flight)

So I don't think we need to be excessively worried about a "failed seal" in the heat shield. They have experience with the material, and flight experience to boot.
Thanks Lars_J, I was just searching for those pictures.
 It seems reasonable that the feet would be made from a similar material as the attachment points in these pictures. No PICAX involved, no hatch.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 06/02/2014 09:28 pm
My point is just that parachutes do not allow "pinpoint guidance" -- which is especially important in abort situations (as in the linked Soyuz example).

Before you make a statement you might want to "google" it first:
http://www.atair.com/
http://www.popularmechanics.com/technology/military/4257762
http://www.airborne-sys.com/pages/view/us-army-selects-dragonfly-and-firefly-self-guided-

"Guided" parachutes have been available both commercially and otherwise for a number of years, so "yes" in fact parachutes DO allow for "pinpoint guidance."

The main reason no SPACE PROGRAM generally uses them is because the control and actuator systems to control the parachutes are more difficlt to build into a design but it HAS been done. The X-38 demonstrator used a guided parafoil for low speed flight and landing.

Randy

X-38 was a lifting body with a parafoil.  Of course it had more control over it landed than a capsule coming down under parachutes.
They had some plans for it on Orion as well...
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: guckyfan on 06/02/2014 09:29 pm
Remember that the Dragon heatshield was calculated to be sufficient for the 14km/s return velocity of Inspiration Mars though just barely. And that was for version 1 of PicaX.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 09:36 pm
As has been noted earlier, the Pica-X material is very low-density, so the footpads are almost certainly *not* Pica-X.

There isn't sufficient evidence to say "almost certainly".  They may or may not be.  It may be that they are PICA-X and they are crushed on landing but they are replaced before the next flight.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: ChrisWilson68 on 06/02/2014 09:44 pm
Just for some clarifications:

Musk stated PICA-X gen 3 heating rate is roughly 1000W/CM^2. It is secret, so I don't expect actual numbers. But if the Wiki entry is correct, the original NASA PICA is 1200W/CM^2.

Not that it matters too much, unless DV2 is expected to return from BEO, like Stardust did, and Orion is supposed to do.

The W/cm^2 is a function not just of the material but also of the thickness.  Make it thicker and it can stand more Watts per square centimeter.

So, if Stardust could withstand 1200 W/cm^2 and Dragon V2's heat shield can withstand 1000 W/cm^2, that doesn't mean PICA-X v3 has less capability.  It may just mean they don't put as much on Dragon V2.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Space OurSoul on 06/02/2014 09:49 pm
So you don't like hypergolic propulsive landing, what do you prefer? Wings, parachutes, non-hypergolic propulsive landing? What's the "right" design?

There is only One True Way.

https://www.youtube.com/watch?v=7Kp63-an2ts

Hey, my Chief Engineer had a thing for spinning stuff….  :)

Too bad you can't see the Kerbals' faces in this video...

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: MP99 on 06/02/2014 10:02 pm
I'm guessing the SuperDracos were not fitted into their ports, since it looks like there was light showing through from where the thrust chamber should be?

It doesn't look like light showing through but something shiny being illuminated by the camera light. The pintle would be a good guess.

The inside of the engine bells was silver metal, lit by the white light coming up from the illuminated platform floor below.

Thanks for clarifying. Hadn't appreciated there was a source of illumination from below.

Cheers, Martin
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: flymetothemoon on 06/02/2014 10:20 pm
So you don't like hypergolic propulsive landing, what do you prefer? Wings, parachutes, non-hypergolic propulsive landing? What's the "right" design?

There is only One True Way.


Hey, my Chief Engineer had a thing for spinning stuff….  :)

Too bad you can't see the Kerbals' faces in this video...

Not too clever if you're not on Earth, with air. Elon's machine able to land on earth, moon and Mars... Boeing and SNC have a similar limitation.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: flymetothemoon on 06/02/2014 10:25 pm
While I am thinking about it. Does anyone remember if FH(R) is able to punch a Dragon ballistically to Mars?

I have definitely read thoughts about this question before, but don't remember the discussion or where.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/02/2014 10:29 pm
So you don't like hypergolic propulsive landing, what do you prefer? Wings, parachutes, non-hypergolic propulsive landing? What's the "right" design?

There is only One True Way.

[youtube]7Kp63-an2ts[/youtube]

Hey, my Chief Engineer had a thing for spinning stuff….  :)

Too bad you can't see the Kerbals' faces in this video...



OT but the wiki for this thing states the following regarding Soyuz re-entry ballistic trajectory:"When the Soyuz trim system failed and it went full ballistic, the G levels did rise significantly but without incident to the passengers".

That is not true according to the account of a 2008 Soyuz "passenger" his account of  ballistic re-entry sounds pretty hairy and one of the other "passengers" was injured. Whether it be NASA PAO glossing over things or SpaceX launch manifest and costs hype or opaque aerospace-govt contracts or wiki wrong stuff sometimes getting at the truth regarding spaceflight is not as easy as it should be. Rant finished.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 06/02/2014 10:54 pm
Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.

Not the dead zones you are thinking of, but DC gives you only one shot at the LZ and no ability to go around so zero margin for error and no backup plan.  The video was cut short, but we are already aware of one significant DC failure mode.  If you have any control surface issue during reentry, even Oscar Goldman can't put you back together.  Columbia was a gliding orbiter, and whether an ice strike or debris impact, a capsule is safer and stronger than a system that relies on exposed flight control surfaces.   Challenger would have been survivable with an LAS, but due to design, weight, complexity, cost & delays of adding an escape capsule to an orbiter, this wasn't done, but when you start with a capsule, you are already ahead of the curve.  Now combine parachutes, the system with the greatest proven safety record, and add propulsive landing and you are again ahead.  Add the ability to land safely on both land and water save the issues with required emergency landing sites and TAL.  When looking at dead zones, these must be included as well.

I'll save Jim the time with the following:

Wrong!

Unsubstantiated!

Emotional response!

Irrelevant!


[fixed.... referred to Shuttle as lifting body.... original designs were based on research into LBs but it is not]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/02/2014 11:31 pm
Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.

Not the dead zones you are thinking of, but DC gives you only one shot at the LZ and no ability to go around so zero margin for error and no backup plan.  The video was cut short, but we are already aware of one significant DC failure mode.  If you have any control surface issue during reentry, even Oscar Goldman can't put you back together.  Columbia was a lifting body, and whether an ice strike or debris impact, a capsule is safer and stronger than a system that relies on exposed flight control surfaces.   Challenger would have been survivable with an LAS, but due to design, weight, complexity, cost & delays of adding an escape capsule to a lifting body, this wasn't done, but when you start with a capsule, you are already ahead of the curve.  Now combine parachutes, the system with the greatest proven safety record, and add propulsive landing and you are again ahead.  Add the ability to land safely on both land and water save the issues with required emergency landing sites and TAL.  When looking at dead zones, these must be included as well.

I'll save Jim the time with the following:

Wrong!

Unsubstantiated!

Emotional response!

Irrelevant!

That part about "any control surface issues during re-entry" applies to all s/c. Including capsules. I just read about it wrt to Soyuz and a bolt that kept a service module connected to the crew capsule which screwed up the re-entry trajectory (went ballistic).



Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Robotbeat on 06/03/2014 01:06 am
Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.

Not the dead zones you are thinking of, but DC gives you only one shot at the LZ and no ability to go around so zero margin for error and no backup plan.  The video was cut short, but we are already aware of one significant DC failure mode.  If you have any control surface issue during reentry, even Oscar Goldman can't put you back together.  Columbia was a lifting body, and whether an ice strike or debris impact, a capsule is safer and stronger than a system that relies on exposed flight control surfaces.   Challenger would have been survivable with an LAS, but due to design, weight, complexity, cost & delays of adding an escape capsule to a lifting body, this wasn't done, but when you start with a capsule, you are already ahead of the curve.  Now combine parachutes, the system with the greatest proven safety record, and add propulsive landing and you are again ahead.  Add the ability to land safely on both land and water save the issues with required emergency landing sites and TAL.  When looking at dead zones, these must be included as well.

I'll save Jim the time with the following:

Wrong!

Unsubstantiated!

Emotional response!

Irrelevant!

That part about "any control surface issues during re-entry" applies to all s/c. Including capsules. I just read about it wrt to Soyuz and a bolt that kept a service module connected to the crew capsule which screwed up the re-entry trajectory (went ballistic).
You just proved his point since that flight was non-fatal.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Will on 06/03/2014 01:18 am
Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.

Not the dead zones you are thinking of, but DC gives you only one shot at the LZ and no ability to go around so zero margin for error and no backup plan.  The video was cut short, but we are already aware of one significant DC failure mode.  If you have any control surface issue during reentry, even Oscar Goldman can't put you back together.  Columbia was a lifting body, and whether an ice strike or debris impact, a capsule is safer and stronger than a system that relies on exposed flight control surfaces.   Challenger would have been survivable with an LAS, but due to design, weight, complexity, cost & delays of adding an escape capsule to a lifting body, this wasn't done, but when you start with a capsule, you are already ahead of the curve.  Now combine parachutes, the system with the greatest proven safety record, and add propulsive landing and you are again ahead.  Add the ability to land safely on both land and water save the issues with required emergency landing sites and TAL.  When looking at dead zones, these must be included as well.

I'll save Jim the time with the following:

Wrong!

Unsubstantiated!

Emotional response!

Irrelevant!

Not Jim. The exclamation points are the giveaway.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Torbjorn Larsson, OM on 06/03/2014 10:48 am
Any reference to fan boys or trolls will result in your entire post being deleted.

Are we crystal clear on that?

If you THINK someone is trolling, you hit report to moderator.

Especial thanks for deleting my attempt at defanging pun in just that context, now that it's a nice party again!

And now I know the level of detail at which the threads are moderated.

Edit: I have now localized and instead reported the offending comment that could (or perhaps should) be deleted as per policy. [/newbie training]
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 06/03/2014 12:14 pm
Just for some clarifications:

Musk stated PICA-X gen 3 heating rate is roughly 1000W/CM^2. It is secret, so I don't expect actual numbers. But if the Wiki entry is correct, the original NASA PICA is 1200W/CM^2.

Not that it matters too much, unless DV2 is expected to return from BEO, like Stardust did, and Orion is supposed to do.

Elon says that the material "can handle over a kilowatt per square centimeter", so it's somewhere north of 1000 W/cm^2. He also says that the material can handle twice the kinetic energy it will be exposed to (presumably during LEO reentry, since he mentions Mach 25, which was STS reentry speed).

As I interpreted the announcements at the time, PICA-X v1 had only very slightly better thermal performance that NASA's PICA, but PICA-X was much easier to manufacture. That made sense to me as NASA had a lot of focus on performance for the record-speed reentry of the stardust capsule, so its performance was likely already fairly close to optimal, but NASA did not need care so much about production cost, since it was a one-off.

The v2 and v3 of PICA was focused on reducing ablation rates to improve reusability as Elon said.

So I expect PICA v3 thermal performance to be only slightly better than NASA PICA, like for v1 -- or maybe even slightly worse as a trade vs reusability.

I was surprised that Elon said that it could handle at least twice the orbital *ENERGY* of a LEO reentry. LEO orbital speed is about Mach 25 or 7km/s, so twice the energy is only about 10km/s, when mars reentry is about 14km/s, or 4 x LEO energy,  depending on trajectory IIRC. I hope Elon misspoke and meant at least twice the *SPEED*, so that earlier rumors turn out true: that the heatshield could handle cislunar returns and probably Mars returns.

edit: Also noteworthy is that Elon said that the DV2 re-entry speed was not limited by the material itself, but how much heat was conducted through the heat shield into the structure. That means that for example a heavier structure (a bigger heat sink) or a more heat-tolerant structure behind the heat shield could improve reentry performance. It is also possible that while PICA v2/3 reduced ablation, it might have increased thermal conductivity, since it is probably a good guess that the improvements involved increased carbon content (vs less resin).
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Llian Rhydderch on 06/03/2014 12:49 pm
Just for some clarifications:

Musk stated PICA-X gen 3 heating rate is roughly 1000W/CM^2. It is secret, so I don't expect actual numbers. But if the Wiki entry is correct, the original NASA PICA is 1200W/CM^2.

Not that it matters too much, unless DV2 is expected to return from BEO, like Stardust did, and Orion is supposed to do.

Elon says that the material "can handle over a kilowatt per square centimeter", so it's somewhere north of 1000 W/cm^2. He also says that the material can handle twice the kinetic energy it will be exposed to (presumably during LEO reentry, since he mentions Mach 25, which was STS reentry speed).

As I interpreted the announcements at the time, PICA-X v1 had only very slightly better thermal performance that NASA's PICA, but PICA-X was much easier to manufacture. That made sense to me as NASA had a lot of focus on performance for the record-speed reentry of the stardust capsule, so its performance was likely already fairly close to optimal, but NASA did not need care so much about production cost, since it was a one-off.

The v2 and v3 of PICA was focused on reducing ablation rates to improve reusability as Elon said.

So I expect PICA v3 thermal performance to be only slightly better than NASA PICA, like for v1 -- or maybe even slightly worse as a trade vs reusability.

I was surprised that Elon said that it could handle at least twice the orbital *ENERGY* of a LEO reentry. LEO orbital speed is about Mach 25 or 7km/s, so twice the energy is only about 10km/s, when mars reentry is about 14km/s, or 4 x LEO energy,  depending on trajectory IIRC. I hope Elon misspoke and meant at least twice the *SPEED*, so that earlier rumors turn out true: that the heatshield could handle cislunar returns and probably Mars returns.

edit: Also noteworthy is that Elon said that the DV2 re-entry speed was not limited by the material itself, but how much heat was conducted through the heat shield into the structure. That means that for example a heavier structure (a bigger heat sink) or a more heat-tolerant structure behind the heat shield could improve reentry performance. It is also possible that while PICA v2/3 reduced ablation, it might have increased thermal conductivity, since it is probably a good guess that the improvements involved increased carbon content (vs less resin).

I have no idea of the answer, but I think the question a good one:  twice the energy or twice the velocity?

One additional thought, I hope the answer is eventually put in one of the standard non-party threads.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Giovanni DS on 06/03/2014 02:28 pm
Is this really important? the Dragon V2 is meant for LEO, a lunar or Mars version would probably be different, including the heat shield specs among the other things.

I don't think they can reasonably have one vehicle for all possible uses.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Mongo62 on 06/03/2014 02:46 pm
SpaceX is likely to have decided to have the heat shield be no heavier than is needed for a certain number of LEO reentries plus a reasonable margin of safety. They must have determined that it was more cost-effective to have more but thinner replacement heat shields, which allows a slightly greater payload mass each flight. The important thing is that the heat shield can be replaced when needed.

I would think that the heat shield could be made thick enough for Mars-velocity reentries, but why bother installing such a relatively heavy heat shield unless it's necessary for that mission?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: R7 on 06/03/2014 02:52 pm
Remember that the Dragon heatshield was calculated to be sufficient for the 14km/s return velocity of Inspiration Mars though just barely. And that was for version 1 of PicaX.

Skip or direct reentry?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/03/2014 03:12 pm
I would think that the heat shield could be made thick enough for Mars-velocity reentries, but why bother installing such a relatively heavy heat shield unless it's necessary for that mission?

I was thinking that the heat shield would be made thick enough for (say) 10 LEO flights w/o refurbishment, which would also, incidentally, be thick enough for 1 Mars-return flight (but has to be refurbished/replaced after a single flight).

But it might not be that simple, since Musk indicated that it's actually heat soak, not ablation, which is the limiting factor for Dragon v2.  So you might not be able to "just ablate more".  I'll leave that for someone who knows more about Mars reentry to opine on.

I think it's entirely reasonable to think that the MCT will have a different crew module.  I think the discussion of Mars-return for Dragon v2 is in reference to "stunts" like the Red Dragon mission or throwing a Dragon around the moon or Mars for the first Falcon Heavy flight.  "Could you do it without costly re-engineering?"
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: guckyfan on 06/03/2014 03:33 pm
Remember that the Dragon heatshield was calculated to be sufficient for the 14km/s return velocity of Inspiration Mars though just barely. And that was for version 1 of PicaX.

Skip or direct reentry?

They did the calculations for both and found that direct reentry would be better with PicaX. After what Elon Musk said at the Dragon V2 introduction the outcome may be different with the new PicaX.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: InfraNut2 on 06/03/2014 03:44 pm
It does not make sense to make Dragon Mars/Asteroid-capable, except maybe for the heatshield. The infrequency and looong duration of missions and the much-increased requirements for the foreseeable future make it much more sensible to put all hardware needed for Beyond-Cislunar (L2) in some kind of mission module, and use the Dragon only as a crew launch/return capsule. The only thing that would need to be Mars-rated for the Dragon would then be the heat-shield. (BTW: for NASA missions, Orion will be likely used instead). When its time to switch to a more sustainable architecture, one could switch to a dedicated reusable deep space vehicle at L2 and switch back to the Dragon when returning to L2.

For basic cislunar transport, however, it makes more sense to have that built into the dragon.Cislunar missions could become quite frequent in the relatively near future. Also the capabilities needed are minimal in additional cost beyond a basic Dragon V2, except for propulsion in some cases. 7-10 days ECLSS capacity are already enough for most basic cislunar missions, such as Lunar free-return, to/from L2 gateway or LLO lander etc., although it would be nice to have a little extra margin (up to for example 10-20 days with 4 people, but the DV2 trunk seems to already have reserved space for extra O2 tanks). Star trackers and upgraded radio transceivers and antennas would not cost much more. Not an upgraded heatshield either.

Instead of having separate Dragon V2 versions, it would probably save more money for SpaceX to have a single Dragon variant for LEO and cislunar use where almost all systems are cislunar-capable with the exception of few things that can be easily "plugged in" in the capsule or trunk primarily for increased ECLSS and/or propulsion capacity. The only BIG difference will be that most of the cislunar missions require extra propulsion capacity, and that is most easily solved with a trunk version that is upgraded to a service module with its own propellant tanks and main (draco) orbital maneuvering thrusters (no need to duplicate DV2 RCS).

Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/03/2014 03:51 pm
Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.

Not the dead zones you are thinking of, but DC gives you only one shot at the LZ and no ability to go around so zero margin for error and no backup plan.  The video was cut short, but we are already aware of one significant DC failure mode.  If you have any control surface issue during reentry, even Oscar Goldman can't put you back together.  Columbia was a lifting body, and whether an ice strike or debris impact, a capsule is safer and stronger than a system that relies on exposed flight control surfaces.   Challenger would have been survivable with an LAS, but due to design, weight, complexity, cost & delays of adding an escape capsule to a lifting body, this wasn't done, but when you start with a capsule, you are already ahead of the curve.  Now combine parachutes, the system with the greatest proven safety record, and add propulsive landing and you are again ahead.  Add the ability to land safely on both land and water save the issues with required emergency landing sites and TAL.  When looking at dead zones, these must be included as well.

I'll save Jim the time with the following:

Wrong!

Unsubstantiated!

Emotional response!

Irrelevant!

That part about "any control surface issues during re-entry" applies to all s/c. Including capsules. I just read about it wrt to Soyuz and a bolt that kept a service module connected to the crew capsule which screwed up the re-entry trajectory (went ballistic).
You just proved his point since that flight was non-fatal.

It was a close call according to the cosmo's account. Lets be frank the DC crash was survivable too, but instead it is mocked above with references to "The 6 Million Dollar Man".

New gloss, same as the old gloss.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: AJW on 06/03/2014 06:20 pm

Secondly because "propulsive-flight-control" (focusing on the whole flight envelope rather than any one "phase" here) is by its nature a safer, more reliable system from end-to-end. Why? Parachutes and wing (lifting) flight both have unavoidable "dead-zones" where they will not function properly. Specifically they have an altitude and minimum-speed requirement respectivly below which they can't function. Propulsive is a "zero-to-maximum" system at any point. If it works at all, as long as it has propellant there are no "dead-zone" restrictions

Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.


It was a close call according to the cosmo's account. Lets be frank the DC crash was survivable too, but instead it is mocked above with references to "The Bionic Man".

New gloss, same as the old gloss.

The reference was relevant and intentional based on this thread's title.   DC is subject to the same issues as the M-2/F2 which lost airspeed, was unable to raise the nose of the craft and missed the runway.  Gliders will always be subject to dependencies of trading altitude for distance and/or speed.  When you run out of altitude, you have nothing left to trade.  Jim stated that DC had no dead zones, and the M-2/F2 demonstrated multiple issues.  Inability to go around, inability to reach a runway, inability to recover from low-altitude stall, and the DC will be subject to these same issues.  DV2 uses parachutes as a backup and I haven't spotted this on DC.  Water landings are also a concern, so to me a dead zone includes any circumstance when you are unable to make a safe landing which is why I mentioned Shuttle ELS & TAL.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Jim on 06/03/2014 06:48 pm

The reference was relevant and intentional based on this thread's title.   DC is subject to the same issues as the M-2/F2 which lost airspeed, was unable to raise the nose of the craft and missed the runway.  Gliders will always be subject to dependencies of trading altitude for distance and/or speed.  When you run out of altitude, you have nothing left to trade.  Jim stated that DC had no dead zones, and the M-2/F2 demonstrated multiple issues.  Inability to go around, inability to reach a runway, inability to recover from low-altitude stall, and the DC will be subject to these same issues.

Did the shuttle every miss the runway?  Energy management is not an issue.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 06/03/2014 07:09 pm
Did the shuttle every miss the runway?  Energy management is not an issue.

STS-37 landed short, but the lessons learned from that event made that far less likely in the future.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Prober on 06/03/2014 07:13 pm
huh?  where's the video on the  V2 parachute drop test ?
NASA released the video a couple of months ago.  But that V2 was boilerplate, without the new shape and SD pods.  But it did have the new nose cap, which confused many people at the time.

thx for the memory jog
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: pagheca on 06/03/2014 07:16 pm
there may be ANY concession to aesthetic in Dragon V2 design?
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/03/2014 07:20 pm
there may be ANY concession to aesthetic in D-V2 design?

There are some nifty logos!  And the seats look pretty sharp.

But the white/black coloring is functional, and the moldline is functional (probably tested in a hypersonic wind tunnel already), etc.  Pretty much everything on the outside is dictated by functional concerns.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Lee Jay on 06/03/2014 07:25 pm
The video was cut short, but we are already aware of one significant DC failure mode.  If you have any control surface issue during reentry, even Oscar Goldman can't put you back together.

That's false.  DC has control surface redundancy, and triple redundancy for each surface.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/03/2014 07:34 pm

Secondly because "propulsive-flight-control" (focusing on the whole flight envelope rather than any one "phase" here) is by its nature a safer, more reliable system from end-to-end. Why? Parachutes and wing (lifting) flight both have unavoidable "dead-zones" where they will not function properly. Specifically they have an altitude and minimum-speed requirement respectivly below which they can't function. Propulsive is a "zero-to-maximum" system at any point. If it works at all, as long as it has propellant there are no "dead-zone" restrictions

Not true, what dead zones will  Dream Chaser will have? Its abort system is used as an orbital insertion and deorbit system, since the wings will cover landing.


It was a close call according to the cosmo's account. Lets be frank the DC crash was survivable too, but instead it is mocked above with references to "The Bionic Man".

New gloss, same as the old gloss.

The reference was relevant and intentional based on this thread's title.   DC is subject to the same issues as the M-2/F2 which lost airspeed, was unable to raise the nose of the craft and missed the runway.  Gliders will always be subject to dependencies of trading altitude for distance and/or speed.  When you run out of altitude, you have nothing left to trade.  Jim stated that DC had no dead zones, and the M-2/F2 demonstrated multiple issues.  Inability to go around, inability to reach a runway, inability to recover from low-altitude stall, and the DC will be subject to these same issues.  DV2 uses parachutes as a backup and I haven't spotted this on DC.  Water landings are also a concern, so to me a dead zone includes any circumstance when you are unable to make a safe landing which is why I mentioned Shuttle ELS & TAL.

Okay 30 years of successful shuttle landings (some blown tires) and anyway ever heard of the Gimli Glider? How about the AirTransat airbus flight landing in the Canaries? These are big commercial airliners that are supposed to do powered landings, but they ran out of fuel and had to glide to safety. Which they did, successfully. Plus I just find it amusing that concerns over hpl are kind of dismissed but gliding to a landing is bad. This is the EM effect in action. He didn't like/select/develop a s/c that glides unpowered to a landing, so therefore it is to be poo-poohed.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Elmar Moelzer on 06/03/2014 07:52 pm
Okay 30 years of successful shuttle landings (some blown tires) and anyway ever heard of the Gimli Glider? How about the AirTransat airbus flight landing in the Canaries? These are big commercial airliners that are supposed to do powered landings, but they ran out of fuel and had to glide to safety. Which they did, successfully. Plus I just find it amusing that concerns over hpl are kind of dismissed but gliding to a landing is bad. This is the EM effect in action. He didn't like/select/develop a s/c that glides unpowered to a landing, so therefore it is to be poo-poohed.
No, I think the whole thing came up as a response to a poster who stated that SpaceX method of propulsive landing was inferior to others like the DC... So it was not intended to bash DC but to defend Dragon.
Personally, I cant understand why some people seem to have a problem with powered landing. We used it successfully (every time) to land Astronauts on the moon decades ago. Technology has only improved since then.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: cscott on 06/03/2014 07:56 pm
This is the EM effect in action. He didn't like/select/develop a s/c that glides unpowered to a landing, so therefore it is to be poo-poohed.

No, it's just the result of a rather tedious flame war where each side is selectively quoting and then shifting their argument so that nothing actually makes sense in isolation any more.

I *think* the original point was something about how hauling SuperDracos to orbit and then reusing them for propulsive landing had the nice benefit that they could be used to recover from second-stage failures.  Then we got into a tedious discussion of whether second-stage failures were common, or if they happened whether you needed the thrust of a superdraco to escape for them or whether ordinary RCS was enough, then some people generalized to talking about dead zones, then people felt compelled to stretch their argument by saying that Dragon V2 was the *only* vehicle without dead zones, and now we've circled round to the old rockets-vs-wings argument.

Sigh.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/03/2014 08:21 pm
Okay 30 years of successful shuttle landings (some blown tires) and anyway ever heard of the Gimli Glider? How about the AirTransat airbus flight landing in the Canaries? These are big commercial airliners that are supposed to do powered landings, but they ran out of fuel and had to glide to safety. Which they did, successfully. Plus I just find it amusing that concerns over hpl are kind of dismissed but gliding to a landing is bad. This is the EM effect in action. He didn't like/select/develop a s/c that glides unpowered to a landing, so therefore it is to be poo-poohed.
No, I think the whole thing came up as a response to a poster who stated that SpaceX method of propulsive landing was inferior to others like the DC... So it was not intended to bash DC but to defend Dragon.
Personally, I cant understand why some people seem to have a problem with powered landing. We used it successfully (every time) to land Astronauts on the moon decades ago. Technology has only improved since then.

That will need to be the case because Dragon2 will land in earth's much stronger (6x?) gravity and thick oxygen/nitrogen atmosphere, unlike the moon's vacuum.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Rocket Science on 06/03/2014 08:40 pm
The Moon argument is a bit of a red herring... how else are you going to land on it, not many options...? Carry on... ;D
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: veblen on 06/03/2014 08:41 pm
A Canadian band, out of Montreal, I prefer Saga or The Box. MWH were okay.
Title: Re: SpaceX: Dragon V2 Unveil - Discussion/Party Thread.
Post by: Chris Bergin on 06/03/2014 09:09 pm
Right, that locked this thread.

We have the update thread, the video thread and the Garrett thread to use.