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SpaceX Vehicles and Missions => SpaceX Missions Section => Topic started by: Chris Bergin on 01/18/2016 01:23 pm

Title: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 01/18/2016 01:23 pm
Kicking off a CRS-8 Discussion Thread, moving out of the manifest discussion thread. This is Dragon's own RTF (not that she did anything wrong during CRS-7) and first launch on the upgraded F9.

Resources:

SpaceX News Articles from 2006 (Including numerous exclusive Elon interviews):
http://forum.nasaspaceflight.com/index.php?topic=21862.0

SpaceX News Articles (Recent):
http://www.nasaspaceflight.com/tag/spacex/

SpaceX Dragon Articles:
http://www.nasaspaceflight.com/tag/dragon/

=--=

Update and Party Threads will be created nearer to the event.

=--=

L2 SpaceX Section:
http://forum.nasaspaceflight.com/index.php?topic=24469.0
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Danderman on 01/19/2016 04:36 am
This is supposed to carry BEAM (http://space.skyrocket.de/doc_sdat/beam.htm) and 16 PlanetLabs CubeSATs to be deployed by Nanoracks.

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 01/22/2016 01:24 pm
On the books (FPIP) for March 20. We should start to see updates for this one soon, and we'll start an update thread at that time. Obviously SES-9 to launch first.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: solartear on 01/22/2016 04:57 pm
The 1,360 kg BEAM will be by far the heaviest trunk cargo to date. Good to see it getting a workout after the loss of IDA-1.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CorvusCorax on 01/23/2016 12:05 pm
This is Dragon's own RTF (not that she did anything wrong during CRS-7)

Didn't do anything "right" either -   like for example deploying parachutes on the way down ... ;)

There's always room for improvement ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Craftyatom on 01/23/2016 03:28 pm
This is Dragon's own RTF (not that she did anything wrong during CRS-7)

Didn't do anything "right" either -   like for example deploying parachutes on the way down ... ;)

There's always room for improvement ;)

On the other hand, let's hope she never gets the chance, especially on flight #3 for Full Thrust.

Edit: got the number wrong.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 01/23/2016 05:33 pm
This is Dragon's own RTF (not that she did anything wrong during CRS-7)

Didn't do anything "right" either -   like for example deploying parachutes on the way down ... ;)

There's always room for improvement ;)

This is specious.
Dragon did everything right for a first stage burn: nothing
"Don't just do something. Sit there!"
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 01/23/2016 07:37 pm
Is there any chance CRS-8 could move to LC-39A and let the queue of commercial launches roll at LC-40?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Zed_Noir on 01/23/2016 08:09 pm
Is there any chance CRS-8 could move to LC-39A and let the queue of commercial launches roll at LC-40?

Ain't you forgetting the Falcon Heavy Demo?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 01/23/2016 08:30 pm
Is there any chance CRS-8 could move to LC-39A and let the queue of commercial launches roll at LC-40?

Ain't you forgetting the Falcon Heavy Demo?

Which is coming Real Soon Now (TM)...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 01/23/2016 09:42 pm
Is there any chance CRS-8 could move to LC-39A and let the queue of commercial launches roll at LC-40?

Ain't you forgetting the Falcon Heavy Demo?

If FH is ready for 39A, then even better.
Don't think it's ready. Hopefully this summer.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 01/24/2016 12:08 am
I'm not going to expect Falcon Heavy this year until I hear sign of it arriving at McGregor. Testing there should be pretty visible, and I expect multiple full-thrust tests of various durations until they are comfortable enough for a first flight.

LC-39A might then be ready before Falcon Heavy is. LC-39A is planned to take care of all non-polar government launches, I believe. Certainly Dragon and initial non-polar Falcon Heavy launches will take place from there. So there's going to be a transition to LC-39A for Dragon eventually, though almost certainly not in time for CRS-8.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: shooter6947 on 01/24/2016 05:47 am
On the books (FPIP) for March 20.  Obviously SES-9 to launch first.

That leaves a 5-week gap between SES-9 & CRS-8.  Would they move Eutelsat up to late February to fill the gap, or will CRS-8 be the next mission after SES-9?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 01/24/2016 12:01 pm
That leaves a 5-week gap between SES-9 & CRS-8.  Would they move Eutelsat up to late February to fill the gap, or will CRS-8 be the next mission after SES-9?

If you believe the 5-week gap is merely due to CRS scheduling, why do you think there's at least a 6 week gap between OG-2 and SES-9?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rockets4life97 on 01/24/2016 01:14 pm
Because Jason-3 was in between. I think 1 launch every 3 weeks (regardless of pad location) is what we can expect right now.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 01/24/2016 01:21 pm
Jason-3 was out of VAFB. How did they manage to find time to refire the OG-2 booster at LC-40 if Jason-3 got them tied up that much?

That kind of logic doesn't hold water, IMHO. They might need a couple of days for static fire/post-launch data review before signing off on the next launch, but there is no reason to completely stop all processing flows just because there's a launch at the west coast.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rockets4life97 on 01/24/2016 01:27 pm
My thinking is that the pad flow is not the constraint (they've had fast turn arounds before).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 01/24/2016 01:36 pm
Yes, when they had boosters stacked up and ready to go (like after the first Orbcomm launch because it got delayed a lot, vehicle production caught up). They now significantly changed the vehicle again. So why do people assume the delays are external (like above, suggesting squeezing Eutelsat in) and not the inability of SpaceX to maintain launch cadence? SES-9 sitting at CCAFS for a month and a half now seems to be telling a different tale.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 01/24/2016 02:09 pm
Yes, when they had boosters stacked up and ready to go (like after the first Orbcomm launch because it got delayed a lot, vehicle production caught up). They now significantly changed the vehicle again. So why do people assume the delays are external (like above, suggesting squeezing Eutelsat in) and not the inability of SpaceX to maintain launch cadence? SES-9 sitting at CCAFS for a month and a half now seems to be telling a different tale.

And let's remember the OG2 stage re-fire at LC40 was in part to wring out the pad GSE, which appears to have some bugs from the densification upgrades, so the transition to Full Thrust has not been without the usual glitches.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 01/24/2016 02:42 pm
"Unable to maintain launch cadence" is not a cause but a symptom. "Problem with the GSE" is a cause.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 02/03/2016 12:56 am
I don't know how to embed Facebook links, but the Bigelow FB page tonight posted a photo of BEAM being hoisted into the Dragon trunk.

EDITED TO ADD: Here, let's try this:
https://www.facebook.com/bigelowaerospace/photos/a.585033308314335.1073741828.582846395199693/603617449789254
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Flying Beaver on 02/03/2016 01:04 am
I don't know how to embed Facebook links, but the Bigelow FB page tonight posted a photo of BEAM being hoisted into the Dragon trunk.

EDITED TO ADD: Here, let's try this:
https://www.facebook.com/bigelowaerospace/photos/a.585033308314335.1073741828.582846395199693/603617449789254


"SpaceX Dragon meeting BEAM (Bigelow Expandable Activity Module) for the first time."

Sounds like a fit check.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CraigLieb on 02/03/2016 02:27 am
I don't know how to embed Facebook links, but the Bigelow FB page tonight posted a photo of BEAM being hoisted into the Dragon trunk.

EDITED TO ADD: Here, let's try this:
https://www.facebook.com/bigelowaerospace/photos/a.585033308314335.1073741828.582846395199693/603617449789254


"SpaceX Dragon meeting BEAM (Bigelow Expandable Activity Module) for the first time."

Sounds like a fit check.

If it was a fit check why would the trunk have solar panels attached? Don't they have a trunk simulator or test article for fit checks and training purposes? Looks like the real deal to me.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 02/03/2016 03:35 am
I don't know how to embed Facebook links, but the Bigelow FB page tonight posted a photo of BEAM being hoisted into the Dragon trunk.

EDITED TO ADD: Here, let's try this:
https://www.facebook.com/bigelowaerospace/photos/a.585033308314335.1073741828.582846395199693/603617449789254

And here is the photo attached:
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 02/03/2016 12:51 pm

 Don't they have a trunk simulator or test article for fit checks and training purposes? Looks like the real deal to me.

Fitchecks are done with flight hardware and not simulators.  Not that this might be a fit check
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: oldAtlas_Eguy on 02/03/2016 04:19 pm
The stand the trunk is on is the one used for vertical to horizontal rotation. This is the GSE used in the normal payload processing for a CRS mission. This is probably the first step in the mating process of Beam into the Trunk. If everything "fits" they would not remove it to make alterations "fixes". The mating would be complete. The statement just means it is the first attempt.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JBF on 02/03/2016 06:40 pm
Does anyone have information/pictures on the mating structure they are using to hold BEAM in the trunk?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: SWGlassPit on 02/04/2016 04:37 pm
Does anyone have information/pictures on the mating structure they are using to hold BEAM in the trunk?

That is almost undoubtedly proprietary to both SpaceX and Bigelow.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: DanseMacabre on 02/05/2016 01:36 pm
Update of a possible slip to 1 April (April fools anyone?!): http://www.grimm-space-research.com/page4/Blog/Blog.html

Interesting note seems to be that the delay is more due to the VV schedule than SpX/F9 readiness, which is possibly a good sign.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rsdavis9 on 02/05/2016 02:52 pm
whats 'VV Schedule'
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Paul Adams on 02/05/2016 02:54 pm
Visiting Vehicle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Paul_G on 02/05/2016 02:55 pm
whats 'VV Schedule'

Visiting Vehicle?

Managing traffic to from the ISS is quite a task I understand.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: psloss on 02/05/2016 07:37 pm
Update of a possible slip to 1 April (April fools anyone?!): http://www.grimm-space-research.com/page4/Blog/Blog.html

Interesting note seems to be that the delay is more due to the VV schedule than SpX/F9 readiness, which is possibly a good sign.
Where it says "Another mission launching to the ISS is delayed which is why SpaceX 8 will be moved also." was referring to something that broke a few minutes ago (that other mission being OA-6):
https://forum.nasaspaceflight.com/index.php?topic=38233.msg1488234#msg1488234
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Grandpa to Two on 02/05/2016 11:01 pm
It's nice to see the worker along side the trunk to give me a good perspective of the trunks actual size. A picture is worth a thousand words (and numbers).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 02/06/2016 04:45 pm
Makes sense, especially with Cygnus getting the new date. I'm sure NASA will make the U/R date official soonish.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 02/08/2016 07:16 pm
Article to mark the latest schedule notes.

http://www.nasaspaceflight.com/2016/02/spacex-prepares-ses-9-mission-dragons-return/

---

This kicks off the CRS-8 Update Only Thread:
http://forum.nasaspaceflight.com/index.php?topic=39537.0
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Raj2014 on 02/09/2016 01:29 pm
I hope the CRS-8 launch on 1st April is not a joke. It would be excellent to see the CRS-8 finally launch and see the B.E.A.M attached to the ISS. Will this launch also use the Falcon v1.2?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Toastmastern on 02/09/2016 01:33 pm
I hope the CRS-8 launch on 1st April is not a joke. It would be excellent to see the CRS-8 finally launch and see the B.E.A.M attached to the ISS. Will this launch also use the Falcon v1.2?

Yea, SpaceX will stick to the Falcon 9 FT(1.2) from now on. Jason-3 was the last Falcon 9 1.1 to launch
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kryten on 02/09/2016 06:36 pm
I hope the CRS-8 launch on 1st April is not a joke. It would be excellent to see the CRS-8 finally launch and see the B.E.A.M attached to the ISS. Will this launch also use the Falcon v1.2?

Yea, SpaceX will stick to the Falcon 9 FT(1.2) from now on. Jason-3 was the last Falcon 9 1.1 to launch
Unless you count the 1.1-based (IIRC) in-flight abort vehicle.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Raj2014 on 02/09/2016 08:49 pm
Will SpaceX attempt a landing again? If yes, where will Falcon land?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rik ISS-fan on 02/09/2016 11:01 pm
For the CRS-8 launched from Cape Canaveral, if they attempt landing with is very likely, it is most likely at Landing zone 1 LZ-1. Although possibly it's a barge landing because the Dragon is heavy, it caries the BEAM and is possibly heavily loaded. I don't know, I think LZ-1. 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rik ISS-fan on 02/09/2016 11:05 pm
Unless you count the 1.1-based (IIRC) in-flight abort vehicle.

Isn't that the F9 v1.1 aka Grasshopper Dev2 with only three engines? Or is it a full F9 v1.1 or did they change  the plan to a F9 FT? Do we know this for certain? 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: whitelancer64 on 02/09/2016 11:12 pm
Unless you count the 1.1-based (IIRC) in-flight abort vehicle.

Isn't that the F9 v1.1 aka Grasshopper Dev2 with only three engines? Or is it a full F9 v1.1 or did they change  the plan to a F9 FT? Do we know this for certain?

It is the F9r Dev2, and it seems unlikely they'd build a new core for the in-flight abort when they have this one available to expend.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lar on 02/09/2016 11:51 pm
I believe that F9FT is preferred to 1.2 but I get confused easily
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 02/10/2016 12:28 am
I believe that F9FT is preferred to 1.2 but I get confused easily

SpaceX wants to completely blur the lines and call all flights of the Falcon 9 just... Falcon 9. No bloody v1.0, v1.1, v1.2, FT, or anything else.

They're all just Falcon 9's.  Period.

At least, that's the direction SpaceX seems to want to go...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 02/10/2016 09:47 am
Correct. Which is why we're not using the "FT" designation in the thread titles. Just F9 now.

PS We're watching the launch date again. Don't have enough specifics for an update yet, but be pre-warned this one could slip again. Rocket issue, enough to threaten the launch date even this far out.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vandersons on 02/10/2016 11:30 am

PS We're watching the launch date again. Don't have enough specifics for an update yet, but be pre-warned this one could slip again. Rocket issue, enough to threaten the launch date even this far out.

If it's a Falcon issue would that not also affect the SES-9 date? Or is it something speciffic to the CRS-8 1st/2nd stage?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 02/10/2016 01:03 pm

PS We're watching the launch date again. Don't have enough specifics for an update yet, but be pre-warned this one could slip again. Rocket issue, enough to threaten the launch date even this far out.

If it's a Falcon issue would that not also affect the SES-9 date? Or is it something speciffic to the CRS-8 1st/2nd stage?

Specific to the CRS-8 F9, so I doubt any relation to SES-9's date.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 02/10/2016 06:57 pm
Still working this. Obviously I wouldn't have said anything unless it was solid info, but nailing down the specifics is always the challenge, thus the vague note above....but I always post if there's a potential impact to the launch date as not saying something and then hearing a reader just booked a hotel and flight.....anyway.

What we know so far:

Hot Fire was completed - that was good.
A subsequent test at McGregor suffered an issue, resulting in damage to the First Stage engine hardware.
We don't know if they can repair at McGregor (would assume they are evaluating that, which would explain why we don't know the plan yet).
No impact to CRS-8's date at this time as they need to know the above before they can evaluate how that fits into the flow, and then ISSP need to work out the Visiting Vehicle slots if they do delay. NASA is aware.

I'll add a line to this weeks article about the hot fire success and subsequent issue, but it'll be for SpaceX (and probably Elon) to say something official. My fear is some overly excited site feeds off this and makes it more dramatic. After all, you guys here understand that issues during testing are always better than issues going uphill....but TechReportAndSomeRocketNewsDramaAlert.com's (not a real site ;) ) readers probably don't.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 02/10/2016 08:12 pm
Hot Fire was completed - that was good.
A subsequent test at McGregor suffered an issue, resulting in damage to the First Stage engine hardware.
Can you clarify if the subsequent test was another test of the same First Stage, or some other test that impacted the First Stage while it was not being tested?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 02/10/2016 08:41 pm
Hot Fire was completed - that was good.
A subsequent test at McGregor suffered an issue, resulting in damage to the First Stage engine hardware.
Can you clarify if the subsequent test was another test of the same First Stage, or some other test that impacted the First Stage while it was not being tested?


CRS-8 S1 - Hot Fire, Friday. Good test.
CRS-8 S1 - Additional test (not a hot fire), Monday. Problem with the test. Caused damage.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MarekCyzio on 02/11/2016 12:01 pm
Are these "additional tests" something that SpaceX does every time or it was something new?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mn on 02/11/2016 02:56 pm
If they are expecting to launch 'every few weeks' I would expect a line of cores nearly ready to go, couldn't the 'next' core in line just move in to this mission while the damaged core gets fixed and put back in the lineup.

Aren't the cores identical?

Is there a reason why the 'next' core can't be used, or are there no cores available? (are cores being produced just barely in time).

Is reassigning cores a no no in this business for some reason?

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OnWithTheShow on 02/11/2016 03:49 pm
A core being ready every three weeks means a three week delay.

Could it have been a landing leg deployment test? Do they have the capability to do that at McGregor?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kryten on 02/11/2016 04:01 pm
A core being ready every three weeks means a three week delay.

Could it have been a landing leg deployment test? Do they have the capability to do that at McGregor?
Chris' updated article has the damage specifically to 'engine hardware', I don't see how the landing legs could do that.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: The Roadie on 02/11/2016 04:07 pm
Could it have been a landing leg deployment test? Do they have the capability to do that at McGregor?
Legs are installed at the Cape. Not present in McGregor.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: The Roadie on 02/11/2016 04:09 pm
Orbital is being delayed due to mold contamination on cargo bags. Might be a bit of pressure relief on CRS8? http://www.floridatoday.com/story/tech/science/space/2016/02/10/black-mold-delays-iss-cargo-launch-cape-canaveral/80174420/?from=global&sessionKey=&autologin=
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: zubenelgenubi on 02/29/2016 11:08 pm
Is there a thread (or segments of threads) about "dual berthing?"

If all goes as currently scheduled, Cygnus OA-6 and Dragon SpX-8 will be the first two craft simultaneously berthed on the USOS portion of the ISS.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Shanuson on 03/02/2016 04:39 pm
Following tweet from Orbital ATK:
Quote from: https://twitter.com/OrbitalATK/status/705051637576892417
[email protected]_Station update: March 22, 2016 has been approved as the launch date for OA-6 mission to resupply the @Space_Station. #Cygnus (1/2)

This makes the Cygnus launch on March 22th official which I think rules out the march 29th launch of CRS-8 shown pending in the picture above.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: feynmanrules on 03/02/2016 08:09 pm
It seems both the orbital and spacex ISS resupply dates have been moved back a day, CRS8 also dependent on successful SES launch though.

Jeff Foust
‏@jeff_foust
Scimemi: SpaceX CRS-8 launch tentatively scheduled for Mar 30, but yet to be finalized; waiting on when SES-9 launches.

https://twitter.com/jeff_foust/status/705093609410834432
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: eriblo on 03/02/2016 09:27 pm
It seems both the orbital and spacex ISS resupply dates have been moved back a day, CRS8 also dependent on successful SES launch though.
[...]
I don't think it's new information, just timezone shenanigans.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 03/03/2016 01:24 am
Quote from: Jeff Foust
Scimemi: SpaceX CRS-8 launch tentatively scheduled for Mar 30, but yet to be finalized; waiting on when SES-9 launches.

https://twitter.com/jeff_foust/status/705093609410834432
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Toastmastern on 03/03/2016 01:47 pm
Saw a video on SpaceX fangroup on Facebook of what seem to be a refire of the first stage after the accident a few weeks back  :)

here is a link for anyone intressted

https://www.facebook.com/groups/spacexgroup/10154020161831318/

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: guckyfan on 03/03/2016 02:50 pm
here is a link for anyone intressted

https://www.facebook.com/groups/spacexgroup/10154020161831318/

Interested but not enough to open a facebook account.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ChefPat on 03/03/2016 03:29 pm
Is the CRS-8 core at Cape Canaveral?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: WHAP on 03/03/2016 03:50 pm
Speculation from that Facebook group is that the core in the video is the one for CRS-8.  If they are correct, then the answer to your question is "no".  Never heard details about the accident.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: RLA on 03/03/2016 06:26 pm
Speculation from that Facebook group is that the core in the video is the one for CRS-8.  If they are correct, then the answer to your question is "no".  Never heard details about the accident.
Lets hope that we get more information soon or later about the mishap.

--
(Edited to remove speculation, because that's what feeds social media and that's where it usually gets misrepresented - Carl, Mod).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 03/03/2016 07:49 pm
The December NASA Advisory Committee meetings discussed CRS-8 (Spx-8).  Page 12 on the linked pdf.

http://www.nasa.gov/sites/default/files/atoms/files/gerstenmaier-heo-tagged.pdf

Quote
Working Dragon trunk latch issue
-Piston rod in latch failed

The meetings took place before the mishap with the stage, so that isn't discussed at all.   And I imagine that the note about the failed latch is well out of date now.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 03/04/2016 12:54 pm
So I've got in from work to some mods pulling this face at me:

(https://s-media-cache-ak0.pinimg.com/236x/3e/62/ef/3e62efbcacf8a6120ea8376354c93803.jpg) <--disclaimer, none of the mods actually look like that, apart from Carl (sorry Carl ;D)

The concern was the CRS-8 core damage info (which we all know about) was becoming more dramatic via people asking questions, people giving part answers, and people making assumptions on that info. I think someone said they worried the stage was damaged via a truck or something...I've missed the mod trim, but no - that was not what happened.

So let me help and then we can all move on.

It happened on the test stand, via a GSE (Ground Support Equipment) error. Not the Stage's fault and thus that's why it didn't impact on SES-9. Nozzles were damaged (not all). Customer (NASA) was told. SpaceX don't want to talk about it, as is their right (and was qualified by a NASA guy who mentioned a different company that had a big test incident and no one ever got to know about it). SpaceX suffer a bit via their fame as they only have to sneeze and its legions of fans want to know about it. An Antares (well Orbital) blows up a NK-33 on a Stennis test stand and there's interest, but far less, as an example.

I assume this has all come back up in conversation because of the Facebook video, but that's cool as it points to this Stage back to good working order and this would be within the schedule to get to the Cape for the current launch date target.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 03/04/2016 12:57 pm
here is a link for anyone intressted

https://www.facebook.com/groups/spacexgroup/10154020161831318/

Interested but not enough to open a facebook account.

Here is the video for those who don't want to open a Facbook account:

http://1drv.ms/1QxyRMx

Credit: Keth Wallace, SpaceX Facebook group.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 03/06/2016 11:39 pm
If this launch is March 30, and Progress launches March 31:

http://forum.nasaspaceflight.com/index.php?topic=39625.0

Is there really no conflict there with ISS operations, keep out zones, etc.?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 03/07/2016 10:06 am
I'm not sure. CRS Dragons have been kept in parking orbits for a couple of days to let other vehicles move in and out around the ISS, so there is no hypothetical problem in launching the vehicle into a parallel orbit and then waiting a couple of days for MCC to give an all clear to commence approach and berthing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vaporcobra on 03/07/2016 10:11 am
If this launch is March 30, and Progress launches March 31:

http://forum.nasaspaceflight.com/index.php?topic=39625.0

Is there really no conflict there with ISS operations, keep out zones, etc.?

It must be said that it is highly unlikely for the NET 3/30 to hold over the next few weeks. Not only is a Progress to be launched on 3/31, but a Cygnus is supposed to launch on 3/22 or 3/23. I believe that the ISS has 6 total ports, with 4 being the maximum number of free ports at any time, as two Soyuz vehicles are kept docked at all times in case of emergency. So, technically, it is possible for another Russian vehicle and two U.S. vehicles to dock at the moment.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: virnin on 03/08/2016 08:25 pm
I'm not sure. CRS Dragons have been kept in parking orbits for a couple of days to let other vehicles move in and out around the ISS, so there is no hypothetical problem in launching the vehicle into a parallel orbit and then waiting a couple of days for MCC to give an all clear to commence approach and berthing.

The Progress should follow the "same day" 6 hour launch to docking profile so the Dragon would arrive the following day.  If Cygnus launches on time, the US crew in the ISS would have almost a week to transfer the berthing camera from one port to the other.  It would be very busy up there but doable since they will be at full strength after Jeff, Oleg and Alexey launch on March 18.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 03/09/2016 06:04 pm
Andrew Rader (@marsrader) on Twitter:

Quote
How you put a Dragon on a Falcon

CRS-8? Can't see the grid fins, but they may be be obscured. Legs are (just about) visible.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 03/09/2016 06:16 pm
That's an image from CRS-4 3.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 03/09/2016 06:36 pm
Ahhh, a reverse image search suggests CRS-3. Wonder what inspired him to tweet that now?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 03/10/2016 01:26 am
Has anyone heard or seen any indications whether or not SpaceX plans to do an RTLS recovery on CRS-8's S1?  I'd have to believe an RTLS is within the envelope of the latest F9 (notice I didn't give it a version number or anything... ;) ) considering the difference in total LEO capability between the latest F9 and the rocket used on prior CRS flights.

I haven't seen the customary links to radio frequency clearances and references to FAA and FCC approvals, etc., that we normally get three to four weeks prior to a scheduled launch, so I figured I'd ask...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: schaban on 03/10/2016 01:29 am
for what it worth, there is no barge on the patch for CRD-8 @ reddit...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jacqmans on 03/10/2016 05:49 am
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinstout on 03/10/2016 07:50 am
Wow,  the one slightly darker star made a surprising emotional impact.  Guess I am a fanboi
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: J-V on 03/10/2016 07:57 am
No barge in the patch. RTLS confirmed then?  ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 03/10/2016 01:11 pm
Has anyone heard or seen any indications whether or not SpaceX plans to do an RTLS recovery on CRS-8's S1?  I'd have to believe an RTLS is within the envelope of the latest F9 (notice I didn't give it a version number or anything... ;) ) considering the difference in total LEO capability between the latest F9 and the rocket used on prior CRS flights.

I haven't seen the customary links to radio frequency clearances and references to FAA and FCC approvals, etc., that we normally get three to four weeks prior to a scheduled launch, so I figured I'd ask...

If we use ORBCOMM-2 as a model, CCAFS and KSC will post a "Incoming!" exclusion zone warning for areas of the range as they did prior to this mission's returning F9--but I suspect you already know this.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevin-rf on 03/10/2016 01:36 pm
No barge in the patch. RTLS confirmed then?  ;)
Maybe they solved the SSTO problem and it will sneak up on Florida from behind ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Prettz on 03/10/2016 03:03 pm
No barge in the patch. RTLS confirmed then?  ;)
I had assumed it was known that RTLS was always possible for CRS missions. Was that not true?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 03/10/2016 03:13 pm
No barge in the patch. RTLS confirmed then?  ;)
I had assumed it was known that RTLS was always possible for CRS missions. Was that not true?

Possible, yes. Approved, no.

It was only with the ORBCOMM-2 mission that RTLS was first approved by the FAA and the range to Landing Zone 1. All other Falcon 9 returning booster test landing attempts, CRS or otherwise, were deliberately soft-landed into the ocean if not given a ASDS for an barge landing.

The Powers That Be were convinced that, despite no successful ASDS landings to that date, that safety conditions were acceptable to let SpaceX try an LZ-1 landing for ORBCOMM-2.

So with that successful landing and with CRS-8's flight profile not requiring high performance (more fuel required), it's possible that RTLS or ASDS landing will occur. But there's been no official word on which location will be used.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ZachS09 on 03/10/2016 04:11 pm
No barge in the patch. RTLS confirmed then?  ;)
I had assumed it was known that RTLS was always possible for CRS missions. Was that not true?

Possible, yes. Approved, no.

It was only with the ORBCOMM-2 mission that RTLS was first approved by the FAA and the range to Landing Zone 1. All other Falcon 9 returning booster test landing attempts, CRS or otherwise, were deliberately soft-landed into the ocean if not given a ASDS for an barge landing.

The Powers That Be were convinced that, despite no successful ASDS landings to that date, that safety conditions were acceptable to let SpaceX try an LZ-1 landing for ORBCOMM-2.

So with that successful landing and with CRS-8's flight profile not requiring high performance (more fuel required), it's possible that RTLS or ASDS landing will occur. But there's been no official word on which location will be used.

They'll probably announce whether or not an RTLS will be attempted on launch day. They did the same for Orbcomm-2.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: edkyle99 on 03/10/2016 04:30 pm
No barge in the patch. RTLS confirmed then?  ;)
I had assumed it was known that RTLS was always possible for CRS missions. Was that not true?
Can I ask where this assumption comes from?  To my knowledge, the payload mass cutoff point for return-to-launch-site first stage recovery has not been announced.  The Orbcomm payload was less than 2 tonnes to a 47 deg orbit.  A fully loaded CRS Dragon is going to weigh 10 tonnes, if not more, and is going to 51.6 deg.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 03/10/2016 05:14 pm
They'll probably announce whether or not an RTLS will be attempted on launch day. They did the same for Orbcomm-2.
But the ASDS Thread 3 (http://forum.nasaspaceflight.com/index.php?topic=39766.0) will be tracking OCISLY to see if it is towed from port several days in advance.
it will also have updates on the status of the repairs.  If the hole is not patched, it is not being used, although the converse cannot be said with confidence.
It seems unlikely that they will dump the first stage in the ocean.  What kind of wastrels would dump a perfectly good booster in the ocean after just one use?  ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 03/10/2016 05:19 pm
Here is what appears to be the FCC transmitter application for CRS-8. Although the mission is not named, the NET March 20 date is consistent with earlier planning for CRS-8, and the coordinates given for the boat/barge location are consistent with a launch azimuth to ISS.

https://apps.fcc.gov/oetcf/els/reports/STA_Print.cfm?mode=current&application_seq=69496&RequestTimeout=1000

As pointed out above, the decision whether to land on the barge or RTLS could be changed until close to launch, but the permit shows that a barge landing is under consideration...or at least it was when the application was filed, before the ASDS was damaged on the SES-9 mission.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 03/10/2016 06:26 pm
The damage to Of Course I still Love You appears to be a 'surface blemish' if that small hole in the deck is the biggest concern.
A day of welding and some paint(optional), and she's good to go. 
Barge repair =/= rocket science.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 03/10/2016 07:02 pm
Has anyone heard or seen any indications whether or not SpaceX plans to do an RTLS recovery on CRS-8's S1?  I'd have to believe an RTLS is within the envelope of the latest F9 (notice I didn't give it a version number or anything... ;) ) considering the difference in total LEO capability between the latest F9 and the rocket used on prior CRS flights.

I haven't seen the customary links to radio frequency clearances and references to FAA and FCC approvals, etc., that we normally get three to four weeks prior to a scheduled launch, so I figured I'd ask...

If we use ORBCOMM-2 as a model, CCAFS and KSC will post a "Incoming!" exclusion zone warning for areas of the range as they did prior to this mission's returning F9--but I suspect you already know this.

Of course I do.  ;)  I was just thinking that, at about this timeframe prior to the Orbcomm RTF, we were starting to see signs and hear rumors that they would attempt an RTLS.  ISTR it was about two weeks prior to RTF that it began to be discussed, based on public-access FAA and FCC applications.

I was only noting that we hadn't heard much in the rumor mill and the only FCC application, AFAIK, was/is for the barge comms.  (Of course, the same application was made for Orbcomm, too -- they held out the ASDS option until the last-minute decision was made.)  I was just wondering if anyone had heard anything (and not just for L2 consumption) either way.

Also, in terms of discussion, does anyone think that the failure of the Jason and SES-9 stage recoveries would provide a basis for FAA refusal of another RTLS attempt until at least one ASDS attempt is successful?  SES-9 was thought to be a real long shot, so that ought not count against SpaceX, but d'you think the FAA might want to see a successful ASDS landing in which there are no landing gear, guidance or propulsion malfunctions before they issue another RTLS permit?  Or do you think the one-for-one performance in RTLS thus far means they'll rubber-stamp such a request?

Where in that continuum do y'all think we lie right now?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 03/10/2016 07:14 pm
Also, in terms of discussion, does anyone think that the failure of the Jason and SES-9 stage recoveries would provide a basis for FAA refusal of another RTLS attempt until at least one ASDS attempt is successful?  SES-9 was thought to be a real long shot, so that ought not count against SpaceX, but d'you think the FAA might want to see a successful ASDS landing in which there are no landing gear, guidance or propulsion malfunctions before they issue another RTLS permit?  Or do you think the one-for-one performance in RTLS thus far means they'll rubber-stamp such a request?

Where in that continuum do y'all think we lie right now?

I can't imagine RTLS permission being refused now with successful RTLS having been demonstrated.

The first RTLS attempt was permitted despite several previous crash landings on the ASDS, and the latest SES-9 attempt was even more of a long shot, both literally and figuratively.

If anything, the crashes on ASDS have shown that (1) the stage terminal guidance is excellent, and (2) damage from the stage coming in hot is relatively minimal, well within the limits of LZ-1 to handle. So in a perverse way, the crashes on ASDS may have helped bolster SpaceX's case that RTLS is relatively safe, even when things go wrong.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 03/10/2016 10:30 pm
I assume, on the patch,  the blue blip on the ISS represents BEAM - is that placement reasonably accurate?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: e of pi on 03/10/2016 10:54 pm
I assume, on the patch,  the blue blip on the ISS represents BEAM - is that placement reasonably accurate?
Node three aft, so that's roughly correct. See the diagram here (https://www.washingtonpost.com/rw/2010-2019/WashingtonPost/2013/01/17/Health-Environment-Science/Graphics/w-NASA0117-gA.jpg), and imagine rotating it 180 degrees.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 03/10/2016 10:54 pm
Also, in terms of discussion, does anyone think that the failure of the Jason and SES-9 stage recoveries would provide a basis for FAA refusal of another RTLS attempt until at least one ASDS attempt is successful?  SES-9 was thought to be a real long shot, so that ought not count against SpaceX, but d'you think the FAA might want to see a successful ASDS landing in which there are no landing gear, guidance or propulsion malfunctions before they issue another RTLS permit?  Or do you think the one-for-one performance in RTLS thus far means they'll rubber-stamp such a request?

Where in that continuum do y'all think we lie right now?


I can't imagine RTLS permission being refused now with successful RTLS having been demonstrated.

The first RTLS attempt was permitted despite several previous crash landings on the ASDS, and the latest SES-9 attempt was even more of a long shot, both literally and figuratively.

If anything, the crashes on ASDS have shown that (1) the stage terminal guidance is excellent, and (2) damage from the stage coming in hot is relatively minimal, well within the limits of LZ-1 to handle. So in a perverse way, the crashes on ASDS may have helped bolster SpaceX's case that RTLS is relatively safe, even when things go wrong.

Concur. Also, the next-to-last ASDS attempt was successful...it was only a landing leg mechanical failure that caused the booster to fall over after the engines were off. SES-9 was known to be short on fuel, so SpaceX was enjoying their "X" as "Experimental" to test high-speed landings and what control authority would work. Data, data, data.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: iamlucky13 on 03/10/2016 11:23 pm
I would think the most important consideration in approving RTLS attempts is not the fact that one landed successfully, but the fact that all of their attempts terminated within a radius significantly smaller than the distance from LZ-1 to anything that the Air Force would regret letting SpaceX hit.

Looked at another way, even if they crashed 10 in a row, but all ten were within 50 meters of the aim point, there's a pretty decent expectation the next one will be within 50 meters, too, and a good chance of an RTLS attempt approval.

On the other hand, if they landed 10 in a row, but one of the ten landed on General Monteith's car in the CCAFS parking lot, there would be some explaining to do before the good general lets them try to land a rocket at his base again.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 03/11/2016 12:17 am
Thanks for the intelligent discussion of the likelihood that the FAA and CCAFS will allow an RTLS on CRS-8.  This is exactly the kind of thing I was looking to establish, before people went off on why or why not an RTLS would be approved.

Good to get good facts established early on this forum, I think... ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: baldusi on 03/11/2016 01:28 am
BTW, hypothetically speaking, they might go with barge landing rather then RTLS just because they want to have a succesful landing. The legs are the new FT design and there's plenty of margin. In other words, even a barge landing would not prove that they can't do a RTLS on CRS missions.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CyndyC on 03/11/2016 03:53 am
I assume, on the patch,  the blue blip on the ISS represents BEAM - is that placement reasonably accurate?
Node three aft, so that's roughly correct. See the diagram here (https://www.washingtonpost.com/rw/2010-2019/WashingtonPost/2013/01/17/Health-Environment-Science/Graphics/w-NASA0117-gA.jpg), and imagine rotating it 180 degrees.

That's interesting to know some of the layers are Kevlar, and that the surface structure is flexible.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 03/11/2016 04:10 am
BTW, hypothetically speaking, they might go with barge landing rather then RTLS just because they want to have a succesful landing. The legs are the new FT design and there's plenty of margin. In other words, even a barge landing would not prove that they can't do a RTLS on CRS missions.
They will have plenty of other chances to do ASDS landing. Why risk loosing the stage with ASDS landing, instead of a very high likelyhood of success on RTLS ?
There will be a few GTO missions that are impossible to RTLS but have just enough performance margin for a "normal" ASDS landing.
Getting a second booster back paves the way for parallel pathways for clearing commercial relaunches (is SpaceX going to skip at least doing a few sub orbital hops, GH2 style ?).
If SpaceX could just launch new stages on CRS / LEO missions and relaunch them on GTO missions, that would be a good start.

The other point they should aim for at least halfway between one and two sigma confidence that RTLS works. A single (or even three or four) landings is far from making it routine. Just as important as pursuing ASDS landings. At least a half a dozen successful RTLS would allow SpaceX to count on those boosters being recovered as 90+% odds.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: guckyfan on 03/11/2016 04:35 am
Getting a second booster back paves the way for parallel pathways for clearing commercial relaunches (is SpaceX going to skip at least doing a few sub orbital hops, GH2 style ?).

Yes, I think they would do that, if New Mexico is ready. If not they maybe can do it in Vandenberg without affecting the launch cadence in Florida. The SES CEO says he is willing to put his satellite on a flown stage without test flights. I am not sure SpaceX is.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 03/11/2016 01:56 pm
I think the decision also hinges on whether SpaceX thinks the booster is "ready" for reflight.  If they have identified issues either by telemetry or by inspection of the Orbcomm stage that they want to address before reflight, and a given booster doesn't yet have those improvements (there's an assembly line, so quite a few stages might come "out" of production before changes introduced at the start of the line (and then qualified, etc) emerge) --- then they may be more willing to risk/work on ASDS landing, since they know that even if the stage was recovered it wouldn't be one they'd refly.

Of course, we have little insight into this from outside, other than noting they may be more willing to work on ASDS landing "now" rather than "later".
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: John Alan on 03/11/2016 02:56 pm
I think this is still very much an experimental phase as far as SpaceX is concerned...
The RTLS landing showed what can be done with lots of margins and a bit of luck...

But barge landings has to work for them... or the ability to underbid all others on price is in jeopardy...
SpaceX needs to get to a point... where they can give good odds of barge recovery statistically... for bidding purposes..

SO... while the whole idea is still in the X phase... you do crazy things like 3 engine landing burns well downrange... etc...
Right now... IMHO... the data from trying new stuff is more valuable to them... puts them ahead of the game.

My opinion... they are on the fence about RTLS or Barge for this flight... not sure yet...
Still processing data from last flight... looking for a case where there is something new to learn if tried...
Weather may also play a part... rough seas=RTLS... IMHO...

SO... they left all reference off the mission patch and left themselves the option to decide later...

My hunch... is this next one will go downrange... single engine landing... the goal is stick it on the barge and bring to home, for once...  ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 03/11/2016 03:42 pm
I think this is still very much an experimental phase as far as SpaceX is concerned...
The RTLS landing showed what can be done with lots of margins and a bit of luck...

But barge landings has to work for them... or the ability to underbid all others on price is in jeopardy...
SpaceX needs to get to a point... where they can give good odds of barge recovery statistically... for bidding purposes..

SO... while the whole idea is still in the X phase... you do crazy things like 3 engine landing burns well downrange... etc...
Right now... IMHO... the data from trying new stuff is more valuable to them... puts them ahead of the game.

My opinion... they are on the fence about RTLS or Barge for this flight... not sure yet...
Still processing data from last flight... looking for a case where there is something new to learn if tried...
Weather may also play a part... rough seas=RTLS... IMHO...

SO... they left all reference off the mission patch and left themselves the option to decide later...

My hunch... is this next one will go downrange... single engine landing... the goal is stick it on the barge and bring to home, for once...  ;)

They already underbid all others on price, in expendable mode. 

What is still to be determined is what margin needs to be reserved for barge landings (I think).  Searching for that parameter will continue as there are many manifested GTO flights around the 5 tonne mark.  They also need data on RTLS landings to inform that piece of the equation since one successful landing is, ...one.

The 30% further reduction in price in 2016-2017 will exacerbate the competition's problem -- instead of a price that is currently 30-40% of the competitions' ($62.5M vs $150-$200M for Atlas/Ariane*), they will be be in the 20-25% range ($40M vs around $150-$200M).  After the 50%-ish reductions promised by the competition for the early 2020s, they will still be able to underbid all others, even if they make zero progress beyond the 30% reduction.

That said, the 30% reduction is likely based on a projected recovery rate that may be unobtainable.

* With the reliability issues, draconian budget cuts, and international political burdens being carried by the Russian launchers, their much more affordable launch prices are not adding market share.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 03/11/2016 03:42 pm
I think this is still very much an experimental phase as far as SpaceX is concerned...
The RTLS landing showed what can be done with lots of margins and a bit of luck...

But barge landings has to work for them... or the ability to underbid all others on price is in jeopardy...
SpaceX needs to get to a point... where they can give good odds of barge recovery statistically... for bidding purposes..

SO... while the whole idea is still in the X phase... you do crazy things like 3 engine landing burns well downrange... etc...
Right now... IMHO... the data from trying new stuff is more valuable to them... puts them ahead of the game.

My opinion... they are on the fence about RTLS or Barge for this flight... not sure yet...
Still processing data from last flight... looking for a case where there is something new to learn if tried...
Weather may also play a part... rough seas=RTLS... IMHO...

SO... they left all reference off the mission patch and left themselves the option to decide later...

My hunch... is this next one will go downrange... single engine landing... the goal is stick it on the barge and bring to home, for once...  ;)

They have plenty of flights on the manifest that can only do ASDS landings.  They will never ever go ASDS if RTLS is possible.

Getting the booster back out weighs any thing they would learn about ASDS landings. 

Also RTLS is faster and less expensive.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 03/11/2016 04:03 pm
Quote
They will never ever go ASDS if RTLS is possible.

I'd be cautious about using the word "never." They have filed a transmitter application with the FCC for a CRS-8 landing on ASDS, which means it's an option they are considering for a mission that probably can also RTLS.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 03/11/2016 04:23 pm
My opinion, unsolicited in this debate but proffered like the others, is that booster recovery and relaunch is currently the priority with plenty of opportunities for ASDS recoveries in the near future.  I think the only determining factors here are the amount of margin in RTLS on a CRS mission. So to look at that we can consider that we need about 2300m/s less ΔV than GTO and we know that F9FT can put 5300kg into GTO. Based on my analysis of FH scenarios it looks to me like taking 800m/s off the requirement for the first stage would leave enough propellant for RTLS. That leaves the upper stage needing 1500m/s less ΔV than it did for SES-9 and that would make the difference between 5.5t payload and 13t payload. Certainly that looks like it is within the realm of possibility for this launch.

But there were a couple other issues that came up on the economics of what SpaceX is doing that are worth commenting on:

The largest single expense that can be reduced in a Falcon 9 launch is reusing the first stage.  The next largest, and one that has no performance impact, is reducing the launch services costs which at the Cape or Vandenberg are mostly outside of SpaceX's control. That is where Boca Chica (and eventually some other location) comes into play. Finally the next domino in cost reduction would be reusing the upper stage except for the performance hit that would have which might wipe out any savings.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 03/11/2016 04:39 pm
  The next largest, and one that has no performance impact, is reducing the launch services costs which at the Cape or Vandenberg

No, that is not the next largest. Propellant costs are more.  and there are others.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 03/11/2016 04:43 pm
  The next largest, and one that has no performance impact, is reducing the launch services costs which at the Cape or Vandenberg

No, that is not the next largest. Propellant costs are more.  and there are others.

Semantics, I am including all fees paid for services at the launch site: propellant, range, facilities, electricity, integration space use etc. To be succinct the set of all costs incurred for a launch after the LV arrives at the launch facility.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 03/11/2016 04:46 pm
  The next largest, and one that has no performance impact, is reducing the launch services costs which at the Cape or Vandenberg

No, that is not the next largest. Propellant costs are more.  and there are others.

Launch services costs less than propellant?

I think Jim needs a raise. ;-)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 03/11/2016 04:54 pm
Ok to be more specific I am working under the assumption that the cost break down for an F9 launch vehicle and launch is roughly:

$2M Transportation to, inspection and testing at McGregor
$10M upper stage manufacturing
$10M gross margin (which is eaten into by any over runs in the other areas)
$15M services, propellant, transportation to launch site, integration, range, and other launch activities
$25M first stage manufacturing
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: John Alan on 03/11/2016 05:07 pm
Since launch contracts are signed some months (years) in advance of flight...
My guess is accountant Elon is asking Engineer Elon... Is this REALLY going to work out as planned...
They kinda need to know sooner then later on this...  ???
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 03/11/2016 05:29 pm
Ok to be more specific I am working under the assumption that the cost break down for an F9 launch vehicle and launch is roughly:

$2M Transportation to, inspection and testing at McGregor
$10M upper stage manufacturing
$10M gross margin (which is eaten into by any over runs in the other areas)
$15M services, propellant, transportation to launch site, integration, range, and other launch activities
$25M first stage manufacturing

I'm just kind of wondering how much you think it costs to ship S1 from CA to TX and from TX to CCAFS.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 03/11/2016 05:29 pm

Semantics, I am including all fees paid for services at the launch site: propellant, range, facilities, electricity, integration space use etc. To be succinct the set of all costs incurred for a launch after the LV arrives at the launch facility.

Well you got your semantics wrong and your premise wrong..  Launch services is the cost of what a spacecraft customer pays.  You are referring to operational costs.  And other than range costs, Spacex does have control over what they pay for those items at VAFB and the Cape

Boca Chica is going to be more for those items.  Spacex gets the benefit of sharing some items with other users.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 03/11/2016 05:50 pm
Ok to be more specific I am working under the assumption that the cost break down for an F9 launch vehicle and launch is roughly:

$2M Transportation to, inspection and testing at McGregor
$10M upper stage manufacturing
$10M gross margin (which is eaten into by any over runs in the other areas)
$15M services, propellant, transportation to launch site, integration, range, and other launch activities
$25M first stage manufacturing

I'm just kind of wondering how much you think it costs to ship S1 from CA to TX and from TX to CCAFS.

including packaging and insurance between $50,000 and $75,000 CA to TX, probably about half TX to CCAFS and probably just a little more to go TX to VAFB.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OnWithTheShow on 03/11/2016 05:51 pm
I'd be cautious about using the word "never." They have filed a transmitter application with the FCC for a CRS-8 landing on ASDS, which means it's an option they are considering for a mission that probably can also RTLS.

Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 03/11/2016 06:01 pm
Ok to be more specific I am working under the assumption that the cost break down for an F9 launch vehicle and launch is roughly:

$2M Transportation to, inspection and testing at McGregor
$10M upper stage manufacturing
$10M gross margin (which is eaten into by any over runs in the other areas)
$15M services, propellant, transportation to launch site, integration, range, and other launch activities
$25M first stage manufacturing

I'm just kind of wondering how much you think it costs to ship S1 from CA to TX and from TX to CCAFS.

including packaging and insurance between $50,000 and $75,000 CA to TX, probably about half TX to CCAFS and probably just a little more to go TX to VAFB.

Don't now about packaging, but that's way too high.  My opinion would be cut it by a factor of 3-4 or so.  I paid less than that (by a lot) to move something far larger and heavier a similar distance and about $12k to move something about that same size about the same distance.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 03/11/2016 06:02 pm
Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....
That is a vanishingly small likelihood, considering the rocket will have just launched from the same location.  It is far more likely that the weather at the ASDS will be no-go than at the Cape.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 03/11/2016 06:08 pm
So I created a new thread to discuss the per launch soft costs as it really doesn't belong in here:

http://forum.nasaspaceflight.com/index.php?topic=39782.0 (http://forum.nasaspaceflight.com/index.php?topic=39782.0)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OnWithTheShow on 03/11/2016 06:38 pm
That is a vanishingly small likelihood, considering the rocket will have just launched from the same location.  It is far more likely that the weather at the ASDS will be no-go than at the Cape.

I havent seen landing weather constraints listed anywhere. You think the likelihood of them being different from launch constraints is slim? I would think wind would be much more of a concern for landing a stage that is mostly unpowered for its flight.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: HMXHMX on 03/11/2016 06:40 pm
  The next largest, and one that has no performance impact, is reducing the launch services costs which at the Cape or Vandenberg

No, that is not the next largest. Propellant costs are more.  and there are others.

So what are current range costs for an F9 class vehicle?  I've heard numbers from $1.5 to over $4M, including fees for GPS metric tracking (which may or may not be range fee).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 03/11/2016 06:42 pm
That is a vanishingly small likelihood, considering the rocket will have just launched from the same location.  It is far more likely that the weather at the ASDS will be no-go than at the Cape.

I havent seen landing weather constraints listed anywhere. You think the likelihood of them being different from launch constraints is slim? I would think wind would be much more of a concern for landing a stage that is mostly unpowered for its flight.

This was discussed before the Orbcomm RTF.  If you look in those threads, you'll see that the wind constraints are worse for launch than landing.  On launch, a slowly accelerating rocket could be blown sideways into pad structure or the lightning masts.  On a more rapidly decelerating descent, which is correcting for winds on-the-fly, and no lightning masts or other structures near the aim point, winds can be significantly higher and not cause a waive-off.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 03/11/2016 08:40 pm
So what are current range costs for an F9 class vehicle?  I've heard numbers from $1.5 to over $4M, including fees for GPS metric tracking (which may or may not be range fee).

I know that recurring costs are much lower after the system MSPSP is approved.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: manoweb on 03/11/2016 08:58 pm
Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....

Can the weather be OK for launch at the Cape and not OK ten minutes later to land?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 03/11/2016 09:01 pm
Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....

Can the weather be OK for launch at the Cape and not OK ten minutes later to land?

Unlikely. The landing winds limit posted for the OG2 RTLS was 50 mph, much higher than the launch winds limit.

http://forum.nasaspaceflight.com/index.php?topic=39146.msg1469912#msg1469912
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 03/11/2016 09:38 pm
You'd have a problem if you, a la Marooned, launched through the eye of a hurricane.  That's the only way I can imagine being within launch limits at T-0 and beyond the landing limits at T+10.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 03/11/2016 09:40 pm
You'd have a problem if you, a la Marooned, launched through the eye of a hurricane.  That's the only way I can imagine being within launch limits at T-0 and beyond the landing limits at T+10.
In that case you wouldn't want to launch for RTLS anyway.  You might be able to land the first stage at LZ-1, but it would be blown over within a half-hour once the eye has left the area.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 03/11/2016 10:14 pm
The damage to Of Course I still Love You appears to be a 'surface blemish' if that small hole in the deck is the biggest concern.
A day of welding and some paint(optional), and she's good to go. 
Barge repair =/= rocket science.

Why even repair it?  What are the odds that it will land in the same place twice?    :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: TomTX on 03/11/2016 11:25 pm
The damage to Of Course I still Love You appears to be a 'surface blemish' if that small hole in the deck is the biggest concern.
A day of welding and some paint(optional), and she's good to go. 
Barge repair =/= rocket science.

Why even repair it?  What are the odds that it will land in the same place twice?    :)

Getting clearance to go out to sea again.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mike_1179 on 03/12/2016 12:13 am
Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....

Can the weather be OK for launch at the Cape and not OK ten minutes later to land?

It happened during shuttle flights where weather was OK to launch but weather at the SLF was no go in case of a RTLS (or the  weather 10 minutes later at the SLF was projected to be no go).

Of course, flying an orbiter along the HAC in winds or thunderstorms is different than dropping in vertically.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: russianhalo117 on 03/12/2016 03:04 am
The damage to Of Course I still Love You appears to be a 'surface blemish' if that small hole in the deck is the biggest concern.
A day of welding and some paint(optional), and she's good to go. 
Barge repair =/= rocket science.

Why even repair it?  What are the odds that it will land in the same place twice?    :)

Getting clearance to go out to sea again.
At least every time we crash a first stage for more science (KSP reference) we don't have to go through lengthy mishap investigations like Delta Mariner (when it last struck and collapsed a road bridge over the Tennessee River), otherwise we'd be building an ASDS for nearly every launch as the previous ones went through lengthy mishap, rebuild, and re-cert.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nomadd on 03/12/2016 03:21 am
Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....

Can the weather be OK for launch at the Cape and not OK ten minutes later to land?
I believe it can be that way simultaneously. Last I heard, they can launch up to 30 knots but can only land up to 20.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 03/12/2016 03:56 am
Something to consider too is that weather could be no-go for landing at the Cape but green downrange at the ASDS....

Can the weather be OK for launch at the Cape and not OK ten minutes later to land?
I believe it can be that way simultaneously. Last I heard, they can launch up to 30 knots but can only land up to 20.

For OG-2 the constraint was 50 mph, not 20 knots.

Landing Weather Looks good
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 03/12/2016 05:58 am
For OG-2 the constraint was 50 mph, not 20 knots.

50 mph converts to ~43.4 kts
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nomadd on 03/12/2016 05:35 pm
For OG-2 the constraint was 50 mph, not 20 knots.

50 mph converts to ~43.4 kts
Are you sure that wasn't upper level winds?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 03/12/2016 05:40 pm
For OG-2 the constraint was 50 mph, not 20 knots.

50 mph converts to ~43.4 kts
Are you sure that wasn't upper level winds?
The image states "Winds below 160 feet < 50 mph."  It could be a typo I guess, but I've always been in the "wind on landing concerns are overblown" camp.  :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 03/12/2016 06:27 pm
So what are current range costs for an F9 class vehicle?  I've heard numbers from $1.5 to over $4M, including fees for GPS metric tracking (which may or may not be range fee).

I know that recurring costs are much lower after the system MSPSP is approved.

Do you mean the Missile System Prelaunch Safety Package (http://snebulos.mit.edu/projects/reference/NASA-Generic/EWR/97ewr-3a.pdf)?

And nadreck is right.  Let's take launch cost discussions here. (http://forum.nasaspaceflight.com/index.php?topic=39782.0)  It's not specific to CRS-8/SpX-8.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: StuffOfInterest on 03/18/2016 02:47 pm
From the update thread:

And that's now official via NASA:

SpaceX’s Dragon cargo spacecraft is targeted for launch at 4:43 p.m. EDT Friday, April 8.

Finally, a day time landing attempt.  If this is a RTLS it could be spectacular.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nate_Trost on 03/18/2016 03:18 pm
Chatting with some SpaceX folks at a conference this week, I asked about CRS-8 landing. Currently, it's still planned for the droneship. Land-landing of CRS is the goal they are working towards, but not quite there yet.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 03/18/2016 04:56 pm
Land-landing of CRS is the goal they are working towards, but not quite there yet.
Well, that's interesting.  I wonder if "working towards" means "we'll do it with the droneship this time, validate our models, then try RTLS for CRS-9" or if it actually means there are changes that need to be made to the rocket to enable it to perform RTLS on a CRS mission.

Of course, this mission will have the heaviest trunk payload to date, so maybe that's a part of the equation too.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 03/18/2016 05:23 pm
Chatting with some SpaceX folks at a conference this week, I asked about CRS-8 landing. Currently, it's still planned for the droneship. Land-landing of CRS is the goal they are working towards, but not quite there yet.

Other sources seem to corroborate this:

A tweet by Loren Grush (The Verge):

Quote
James Stewart  ‏@JamesStewart97  2h2 hours ago United Kingdom
@lorengrush have @SpaceX confirmed that they're going for a first stage drone ship landing rather than a RTLS?

‏@lorengrush
@JamesStewart97 Yep! Got confirmation this morning

https://twitter.com/lorengrush/status/710859540250628096
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kaputnik on 03/18/2016 08:07 pm
Could it perhaps be related to the margins that NASA require?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 03/18/2016 08:25 pm
Could it perhaps be related to the margins that NASA require?
If I had to hazard a guess, it would be that following a LOM on the previous flight, SpaceX is going to use an excess of caution to make sure this flight goes off without a hitch.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 03/18/2016 08:37 pm
Could it perhaps be related to the margins that NASA require?
If I had to hazard a guess, it would be that following a LOM on the previous flight, SpaceX is going to use an excess of caution to make sure this flight goes off without a hitch.

If so, that would be slightly ironic given that the closer you push to 1st stage depletion, the higher the buoyancy-related loads are on 2nd stage struts... I think G throttling only kicks in after what would normally be stage sep for a RTLS profile.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cuddihy on 03/19/2016 12:57 am
Yeah but a lot fewer scrub worries if you don't have to super load sub chilled propellants--use the extra downrange propellant margin to ensure subcooling issues don't scrub you out of your window
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: manoweb on 03/19/2016 05:20 am
cuddihy how do you know they will not load sub cooled propellants exactly like on SES-9 or Orbcomm-2?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 03/19/2016 05:40 am
Discussion I've seen on other sites tends towards them really wanting to get ASDS landings down more than a second RTLS because it is a critical element of future FH reuse and something they want well established prior to the FH demonstration launch.  As well as for any higher mass GTO payloads for the F9.  Ergo, based on their "ideal" future manifest, barge landings will play an overall larger role in their recovery efforts than RTLS.  That puts it at a higher priority on the critical path than just getting a second recovered stage.  Especially when one considers that there are at least a handful of launches "scheduled" for this year that could allow RTLS and at least an equal number that will require barging.  The achieving/improving/perfecting the barge landings will increase recovery rate more.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 03/19/2016 05:48 am
Yeah but a lot fewer scrub worries if you don't have to super load sub chilled propellants--use the extra downrange propellant margin to ensure subcooling issues don't scrub you out of your window

IMO they'll always use the subchilled LOX whether it's performance improvement is technically needed for the mission or not. 

1. It gives them extra margin for both the primary mission and for any booster recovery attempt. 
2.  Landing heavier is actually easier. 
3.  Better to always run your ground operations the same.  Improves reliability as well as simplifying operations.  Makes them easier to automate (a high long term priority for SpaceX) and cheaper.
4.  Don't get too hung up on subchilled LOX being a commonly recurring problem yet.  So far there have been 2 mission that have used it.  Only 1 has experienced issues with the LOX temps.  And according to Ms. Shotwell those were mainly related to the use of new ground-side LOX tanks that had some issue (subsequently resolved?).  I expect something like their troubles with the containers that hold the molecule-not-to-be-named (similar to Hydrogen in mol. mass).  It created some problems for a while, but was eventually handled.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Johnnyhinbos on 03/19/2016 12:19 pm
Plus I doubt the GSE is set up to handle a non sub cooled path.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Karloss12 on 03/19/2016 12:49 pm
Discussion I've seen on other sites tends towards them really wanting to get ASDS landings down more than a second RTLS because it is a critical element of future FH reuse and something they want well established prior to the FH demonstration launch. ....

I agree.  I recon the FH could have been completed and ready for the test launch months ago.  The only thing holding it up is the Statistical Engineers who have some milestones that need to be met to reduce the cost/risk to an optimum level for recovering the cores of the FH.  One of these milestones will be the need for X successful drone ship landings.  There no point in even fabricating the FH if there is at least a year of more of unknown iterative improvements to the F9 before the statisticians milestones can be met.

After all if they don't recover any of the FH cores than that is effectively expending three F9's.  That would be an expensive test.  If they can recover even one FH core then that is 9 Merlins that can be transferred to another F9, or even an entire core that can be reused.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ronsmytheiii on 03/19/2016 01:05 pm
Discussion I've seen on other sites tends towards them really wanting to get ASDS landings down more than a second RTLS because it is a critical element of future FH reuse and something they want well established prior to the FH demonstration launch.

Except SES wants to use a reused stage (I think it is in their contract) Doesnt give SpaceX much time to guarantee a returned stage.

I would imagine that they are still planning for ASDS as it depends on the weather conditions and Range approval for RTLS. Always keep your options ready.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: IntoTheVoid on 03/19/2016 03:23 pm
Yeah but a lot fewer scrub worries if you don't have to super load sub chilled propellants--use the extra downrange propellant margin to ensure subcooling issues don't scrub you out of your window

I don't believe that he's arguing that they won't subcool the propellants. I believe his point was that the margin gained by landing on ASDS rather than RTLS would allow them to launch in spite of minor temperature issues rather than scrub as SES-9 did.

Personally, I doubt this would be their motivating factor because the launch window will not permit them to sit on the pad with the LOX warming up anyway.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 03/19/2016 03:25 pm
Yeah but a lot fewer scrub worries if you don't have to super load sub chilled propellants--use the extra downrange propellant margin to ensure subcooling issues don't scrub you out of your window

It is an instantaneous window, so either you go or you wait for next day.
Sub-cooled propellants being one-shot loads may already be a solved problem, but irrelevant for zero duration windows.

(what IntoTheVoid said)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Billium on 03/20/2016 04:28 pm
I noted that Wikipedia lists the maximum up mass for Dragon at 3,310kg. I noted that BEAM (according to an excellent link to a Boeing article on the update thread) is 1,360kg. This in theory leaves 1,950kg for pressurized cargo.  However I don’t think Dragon has ever delivered more than 1,905kg pressurized cargo before, so it doesn’t seem like carrying BEAM will restrict the pressurized cargo for this mission any more than normal. I wanted to ask however if the maximum up mass is restricted by Dragon or by Falcon 9? (I assume Dragon, and just because we have F9FT now this doesn’t mean they could in theory put more mass on Dragon).

I was really happy to see the transported dimensions/inflated dimensions of BEAM confirmed in the linked article. I noted that the diameter of BEAM for transport is 2.4m. Can anyone confirm the maximum diameter that could be transported in the trunk of Dragon?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 03/20/2016 04:44 pm
Upmass (and down) is limited by space in the dragon and not the F9.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: RDoc on 03/20/2016 06:00 pm
Upmass (and down) is limited by space in the dragon and not the F9.
That seems unlikely. There's lots of volume between the interior and trunk to hold a lot of mass depending on the density, e.g. filling it with water tanks.

I'd believe it's limited by either the structural or RCS capabilities of the Dragon, particularly down mass, but not volume.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 03/20/2016 07:14 pm
Upmass (and down) is limited by space in the dragon and not the F9.
That seems unlikely. There's lots of volume between the interior and trunk to hold a lot of mass depending on the density, e.g. filling it with water tanks.

I'd believe it's limited by either the structural or RCS capabilities of the Dragon, particularly down mass, but not volume.

wrong, it is volume. Also, they don't have tanks for water.   Station logistics is about 25lb per CTB
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 03/20/2016 07:25 pm
Quote
I was really happy to see the transported dimensions/inflated dimensions of BEAM confirmed in the linked article. I noted that the diameter of BEAM for transport is 2.4m. Can anyone confirm the maximum diameter that could be transported in the trunk of Dragon?

You can get a good idea of dimensional limits from this pic of CATS mounted in the trunk. The trunk diameter is 12 ft, and the 2.4m you mentioned for the BEAM module is a bit under 8 ft.

(http://i.imgur.com/Mgn6iQn.jpg)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dorkmo on 03/20/2016 08:18 pm
what if nasa wanted a bunch or uranium plates for micrometeor protection?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: RDoc on 03/20/2016 08:30 pm
Upmass (and down) is limited by space in the dragon and not the F9.
That seems unlikely. There's lots of volume between the interior and trunk to hold a lot of mass depending on the density, e.g. filling it with water tanks.

I'd believe it's limited by either the structural or RCS capabilities of the Dragon, particularly down mass, but not volume.

wrong, it is volume. Also, they don't have tanks for water.   Station logistics is about 25lb per CTB
Hmm, interesting, I hadn't realized that they put the BEAM unit into CTBs. How do they reassemble it?

It's also surprising that there's no difference in maximum mass to orbit if using the pressurized volume, non-pressurized trunk, or both. I'd think that increasing the volume from 10 to 24 cubic meters would have some impact on the maximum up mass if, as you say, it is volume limited.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 03/20/2016 09:59 pm
what if nasa wanted a bunch or uranium plates for micrometeor protection?

Then they'd have lost their minds. There are much better options (such as the current MMOD shields in place on ISS modules), layered ballistic fiber blankets, etc.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: manoweb on 03/21/2016 12:45 am
@Herb Schaltegger I think you have missed the point. NASA could, in principle, decide to send up some material that has a density greater than 1. There might be materials that have a density that makes Dragon very heavy while not being full. This apparently is not very common but possible no?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 03/21/2016 01:00 am
@Herb Schaltegger I think you have missed the point. NASA could, in principle, decide to send up some material that has a density greater than 1. There might be materials that have a density that makes Dragon very heavy while not being full. This apparently is not very common but possible no?

Name one that is realistic, and necessary in large enough quantities. Otherwise this is just nonsense.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: QuantumG on 03/21/2016 01:08 am
Here's an article on the experiments that will be on this launch.

http://www.nasa.gov/mission_pages/station/research/news/experiment_challenges

The nanofluidic studies look neat, and of course there's BEAM. Other than that, it's the same stuff they've been doing for years.

Dragon really is for carrying up tang and t-shirts.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 03/21/2016 01:33 am
Dragon really is for carrying up tang and t-shirts.

QG, you make it sound like tang and t-shirts aren't important..
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: woods170 on 03/21/2016 09:30 am
Here's an article on the experiments that will be on this launch.

http://www.nasa.gov/mission_pages/station/research/news/experiment_challenges (http://www.nasa.gov/mission_pages/station/research/news/experiment_challenges)

The nanofluidic studies look neat, and of course there's BEAM. Other than that, it's the same stuff they've been doing for years.

Dragon really is for carrying up tang and t-shirts.

Well, I suppose an EMU could be seen as some kind of horrendously expensive clothing. And from a distance I suppose BEAM looks like a huge roll of toilet-paper. But other than that stuff like IDA's and other external payloads do not exactly fit the description of 'tang, toilet-paper and t-shirts' (as ever so often voiced by Jim).
But heck, who am I to criticize this 'tang, toilet-paper and t-shirts'-nonsense?  ::)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: PD Engr on 03/21/2016 11:38 am
Here's an article on the experiments that will be on this launch.

http://www.nasa.gov/mission_pages/station/research/news/experiment_challenges

The nanofluidic studies look neat, and of course there's BEAM. Other than that, it's the same stuff they've been doing for years.

Dragon really is for carrying up tang and t-shirts.

Dragon really is for bringing stuff down. There are other vehicle options for upmass.  Downmass, not so much.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ChrisC on 03/23/2016 04:18 am
McGregor leg article for the next two missions, including CRS-8:
https://www.nasaspaceflight.com/2016/03/spacex-prepares-two-missions-mcgregor/

Congrats on the Slashdotting:

https://science.slashdot.org/story/16/03/23/0319213/spacex-sets-april-8-for-next-dragon-launch
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ohsin on 03/24/2016 03:49 am
"Spotted on a road in Florida" near Sanford.

Source (https://www.reddit.com/r/whatisthisthing/comments/4bpi3u/spotted_on_a_road_in_florida/)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: darkenfast on 03/24/2016 08:36 am
I just looked at a map of Florida.  Why would they be off the Interstate there?  Detour or some kind of breakdown?  There's somebody under the tail of the trailer, so it must be stopped or moving very slowly.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: PD Engr on 03/24/2016 11:29 am
I just looked at a map of Florida.  Why would they be off the Interstate there?  Detour or some kind of breakdown?  There's somebody under the tail of the trailer, so it must be stopped or moving very slowly.

Looks a lot like this intersection:

https://www.google.com/maps/@28.7960724,-81.3543277,3a,75y,179.24h,74.85t/data=!3m6!1e1!3m4!1s-YKLgvadzCWzX1Pk7bPBYQ!2e0!7i13312!8i6656!6m1!1e1
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 03/24/2016 11:58 am
I just looked at a map of Florida.  Why would they be off the Interstate there?  Detour or some kind of breakdown?  There's somebody under the tail of the trailer, so it must be stopped or moving very slowly.

The trailer could have rear steering.  You pin those things on the highway but they might be unpinning it to make the corner.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 03/24/2016 12:16 pm
Since the photo was posted yesterday on Reddit (and probably taken in the middle of the day), the stage is most likely on the Cape already.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: b ramsey on 03/24/2016 01:32 pm
Maybe they, just missed their exit, and are doubling back to 417.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Brovane on 03/24/2016 01:46 pm
Maybe they, just missed their exit, and are doubling back to 417.

Trying to "Flip a bitch" with that load must suck.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: leetdan on 03/24/2016 01:51 pm
They would've been coming down I-75, and I'm guessing they skip the Turnpike for toll plaza reasons (the ramp to 528 might be too sharp, and is always busy).  I don't know why they'd ever get on I-4, especially considering all the construction through Orlando.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CraigLieb on 03/24/2016 01:52 pm
Shameless self promotion: Landing Poll just out..
http://forum.nasaspaceflight.com/index.php?topic=39862.0
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kansan52 on 03/24/2016 02:13 pm
Certainly appears the a trying everything they can to straighten when you see how far on the grass they have driven.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dorkmo on 03/24/2016 03:46 pm
i wonder if they werent on the interstate and came in from the west on state highway 46?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: intrepidpursuit on 03/25/2016 06:37 pm
They would've been coming down I-75, and I'm guessing they skip the Turnpike for toll plaza reasons (the ramp to 528 might be too sharp, and is always busy).  I don't know why they'd ever get on I-4, especially considering all the construction through Orlando.

If it were me I would take I-10 to I-295 to I-95 and avoid the Orlando area entirely, but clearly that is not what they did. I-4 is under construction so it would not be passable by anything that size (not that it is ever NOT under construction or passable by anything of any size, but I digress). I agree that they must be coming from 46 via 44 and I-75 and be getting on 417 toward 528 SR-50. Not much out there so just big open roads mostly. The turnpike has ridiculous on/off ramps so I'm not surprised they are avoiding it.

Just 2c from an Orlando native in case it is helpful.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dorkmo on 03/25/2016 07:05 pm
https://www.google.com/maps/dir/28.8838263,-82.0945394/28.5786461,-81.2628713/@28.7378153,-81.9216333,10z/data=!4m14!4m13!1m10!3m4!1m2!1d-81.6415135!2d28.8328854!3s0x88e7a25358079a93:0x2873ba867d416000!3m4!1m2!1d-81.5131376!2d28.8281883!3s0x88e70a7dd1307ee9:0x67481073324ec940!1m0!3e0

perhaps like this eh

we should set up some street cameras ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MarekCyzio on 03/25/2016 07:22 pm
Would be good to map all sightings of F9 rockets in the past. I-95 next to St. John's Pkwy in Port St. John and now we know F9 was seen at 417/International Pkwy in Sanford.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 03/25/2016 07:38 pm
There is no way things come down I-75.  The standard for deliveries to the space center is I-10 to I-95
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: The Roadie on 03/25/2016 07:54 pm
Reddit was wrong or late. Nothing was on the road yesterday or even Wednesday. Stage 23 processing in the HIF. Stage 24 still vertical on McGregor test stand.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dorkmo on 03/25/2016 08:26 pm
There is no way things come down I-75.  The standard for deliveries to the space center is I-10 to I-95

but it was in sanford, fl?

i suppose there could have been something on I-95 to warrant a detour?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: The Roadie on 03/25/2016 08:52 pm
i suppose there could have been something on I-95 to warrant a detour?
400 photogs waiting to take spy pics
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: hans_ober on 03/26/2016 12:28 am
Reddit was wrong or late. Nothing was on the road yesterday or even Wednesday. Stage 23 processing in the HIF. Stage 24 still vertical on McGregor test stand.

I though so too.
Launch on the 8th means Static Fire around the 5th. Do they do the Static Fire with the Dragon on top?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 03/26/2016 08:05 am
Reddit was wrong or late. Nothing was on the road yesterday or even Wednesday. Stage 23 processing in the HIF. Stage 24 still vertical on McGregor test stand.

I though so too.
Launch on the 8th means Static Fire around the 5th. Do they do the Static Fire with the Dragon on top?
Always have before.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 03/26/2016 09:14 am
Do they do the Static Fire with the Dragon on top?
Always have before.

https://www.youtube.com/watch?v=5I7loLnDYyU
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 03/26/2016 09:37 am
Do they do the Static Fire with the Dragon on top?
Always have before.
I stand corrected, though that was many moons ago and SpaceX seems to be leaning towards full integration before static fire now as a way to save time.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 03/26/2016 02:59 pm
They were leaning towards that even then. Events don't always transpire that way, though.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: hans_ober on 03/31/2016 09:39 am
How far out will the barge be?

How is this distance compared to CRS5/ CRS6 / CRS7 attempts?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nick L on 03/31/2016 10:13 am
From ASDS thread:
http://forum.nasaspaceflight.com/index.php?topic=39766.msg1509864#msg1509864
Quote
About 185 statute miles from the point of launchness and about 172 miles from nearest land.

This link provide a comparison between CRS6-7 and CRS8 landing zone:
http://forum.nasaspaceflight.com/index.php?topic=39766.msg1507418#msg1507418
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mdeep on 04/01/2016 07:11 pm
Exactly how much does the launch time shift each day? I saw 4/9 16:20 local posted as a backup on the hazard areas, but didn't want to draw a pattern from just that.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/01/2016 07:31 pm

Not sure how the word "Expendable" fits into this.  Is that a customary word always in that type of release or what?  I'm kind of hoping that the bottom 175 feet or so and the top 14 feet or so aren't expendable.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/01/2016 07:43 pm
<keep-out zone>
Made a visualization on google maps.  Range cartographers, water you doing?
Red is A, Yellow B, Green C, by the way.  Oh, and the end of the yellow area is about 300 miles downrange - 120 closer than the center of the SES-9 keep-out area.

Ok, but keep out zone begins usually at least around the launch pad. ;)
My google map visualization.

https://www.google.com/maps/d/viewer?mid=zPI-aXRtCFwc.kwrYIXaXWCKM

<map posted>

The maps differ vastly. If I was a tug boat captain pulling a load through that area around launch time which of these three maps should I use?  And are the other two erroneous?

edit: I see that the last one is airspace so forget that one - but what is up with the first two?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rlmoser on 04/01/2016 09:22 pm

The maps differ vastly. If I was a tug boat captain pulling a load through that area around launch time which of these three maps should I use?  And are the other two erroneous?

edit: I see that the last one is airspace so forget that one - but what is up with the first two?

I think craftyatom had a typo when he was creating his visualization, it looks like the second data point for section C was entered as 3313N instead of 3113N.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Raul on 04/01/2016 09:48 pm

The maps differ vastly. If I was a tug boat captain pulling a load through that area around launch time which of these three maps should I use?  And are the other two erroneous?

edit: I see that the last one is airspace so forget that one - but what is up with the first two?

I think craftyatom had a typo when he was creating his visualization, it looks like the second data point for section C was entered as 3313N instead of 3113N.
Not only typo of one data point of area C. All areas are wrong. It's typical faulty coordinates interpretation in decimal form.
That's reason why area A is outside the launch pad and area B has tilted nose at the end. (E.g. not 28.36°N, but 28°36'N).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Craftyatom on 04/02/2016 02:03 am
<keep-out zone>
Made a visualization on google maps.  Range cartographers, water you doing?
Red is A, Yellow B, Green C, by the way.  Oh, and the end of the yellow area is about 300 miles downrange - 120 closer than the center of the SES-9 keep-out area.

Ok, but keep out zone begins usually at least around the launch pad. ;)
My google map visualization.

https://www.google.com/maps/d/viewer?mid=zPI-aXRtCFwc.kwrYIXaXWCKM

<map posted>

The maps differ vastly. If I was a tug boat captain pulling a load through that area around launch time which of these three maps should I use?  And are the other two erroneous?

edit: I see that the last one is airspace so forget that one - but what is up with the first two?

Yup, my bad on that one, I'm not used to this coordinate system.  It's close enough to almost be believable, but still quite far from reality.  Still, makes more sense that I screwed up than that the range did.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vulture4 on 04/02/2016 12:06 pm
Over the 30 years I have lived here numerous launches have been delayed, sometimes at great cost, because of boats (and less commonly aircraft) entering the restricted zones during the countdowns. Boaters have long complained that there is no easy way to find out the exact boundaries of the restricted zones and when they are in effect. Text descriptions in press releases are vague and not widely distributed. A website that provides accurate and continuously updated information in graphical format, with distribution though all sties that provide marine and aviation weather information would be more effective.

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/02/2016 03:03 pm
I vastly agree that there's room for an zone clearance website. A phone app that integrates with current position and direction of travel so that you'd get an alarm even if you did nothing would be good as well.  There would be some liability associated with it but that could be overcome with disclaimers.  Targeted advertising revenue for such a narrow audience would probably be good as well.

As for the map differences, when I put the three contender maps in the post above I made the mistake of using the airspace map that jacqmans had put up.  Looking back I see that he also put up a nautical chart.  And it doesn't match Raul's chart.  So I'm back to wondering, what is up with that?  Its no wonder that people stumble into these zones if the information is so unobvious that there can easily be multiple interpretations.  Also, in Raul's zone map what are the markers at the far ends of the zones?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Raul on 04/02/2016 08:58 pm
Also, in Raul's zone map what are the markers at the far ends of the zones?
If you mean blue markers, it's nothing more than auxiliary nodical points of middle track estimated according hazard areas, created for more global SpX map overview.
https://www.google.com/maps/d/viewer?mid=zPI-aXRtCFwc.kYumI0Jr0r_A
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Brian45 on 04/03/2016 03:29 pm
With the Progress and Cygnus currently on station, where is the CRS-8 going to berth?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/03/2016 04:00 pm
With the Progress and Cygnus currently on station, where is the CRS-8 going to berth?

Nadir port of Harmony module, according to spaceflightinsider.com.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/03/2016 04:02 pm
With the Progress and Cygnus currently on station, where is the CRS-8 going to berth?

Progress docks to the Russian end and so never conflicts with American vehicles.
(ESA's ATV used to dock to the Russian end and HTV docks to US Berthing ports.)
Check out the discussion of the ISS FPIPs. (https://forum.nasaspaceflight.com/index.php?topic=29401.msg1504813#msg1504813)
It shows Cygnus docking to Node 2 Nadir and Dragon docking to Node 1 Nadir.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: boog on 04/03/2016 04:36 pm
Once S1 is standing vertically on the drone ship I've heard they will weld shoes over the legs. Will they then cruise back to shore like that? Wouldn't it be safer to translate horizontal? Can they not fit the gear they need for this? My next worry is that they will land but then have tipping problems on the trip back. Does anyone know details on these boots?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/03/2016 05:11 pm
Once S1 is standing vertically on the drone ship I've heard they will weld shoes over the legs. Will they then cruise back to shore like that? Wouldn't it be safer to translate horizontal? Can they not fit the gear they need for this? My next worry is that they will land but then have tipping problems on the trip back. Does anyone know details on these boots?

I strongly suspect that the boots are irrelevant.  I suspect that, if you pushed on the stage until something broke, it wouldn't be the boots, it would be the legs or their supports.

I, too am curious has to how and when they plan to get the stage horizontal again.  It has been doing that job on its own so far, but sooner or later they're going to have to give it some help.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lar on 04/03/2016 05:14 pm
I, too am curious has to how and when they plan to get the stage horizontal again.  It has been doing that job on its own so far, but sooner or later they're going to have to give it some help.
Shore crane.  It will be vertical til then, is my theory.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Stan-1967 on 04/03/2016 05:59 pm
My WAG is that the stage will survive the journey back to port upright just fine, but I think there are other more dangerous unknowns that need to be characterized.

1.  The natural oscillation frequency of the barge, due to wave action, is going to be loading members & joints alternately between tension/compression/torsion during the transit back to port.  With a frequency of around 20s, (which I recall from an ASDS thread here)  that could put around 10^4 cycles on the stage components.   Even with the extra design margins that SpaceX says they have built into Falcon 9 for re-usability, I still think there will be a higer learning curve and validation needed for stages landed and returned on barge landings vs. RTLS.  That amount of cycling could very well lower the ultimate strength of some members, which needs to be understood for reliable re-use.  SpaceX is hopefully installing instrumentation onto the CRS-8 S1, such as accelerometers and strain gages, so they can record loading during transit.   Alternately they could instrument up the recovered Orbcomm 2 stage, secure it on the barge deck,  and send it out to sea to get some data.

2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.   Corrosion mechanisms that were not a problem for single use launches could very well manifest themselves on landed stages subject to that environment.  The environment factors could compound the cyclic loading factors.   
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lar on 04/03/2016 06:35 pm
Agreed that instrumenting up the returned Orbcomm would be a great idea... as long as the CRS-8 landing doesn't make as large a hole as last time there might be time to do that after CRS-8. And if CRS-8 lands safely the safeing crew may well be doing just that to it.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cartman on 04/03/2016 06:40 pm
How hard is it to throw a tarp over the stage?


2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.   Corrosion mechanisms that were not a problem for single use launches could very well manifest themselves on landed stages subject to that environment.  The environment factors could compound the cyclic loading factors.   

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/03/2016 06:54 pm
My WAG is that the stage will survive the journey back to port upright just fine, but I think there are other more dangerous unknowns that need to be characterized.

1.  The natural oscillation frequency of the barge, due to wave action, is going to be loading members & joints alternately between tension/compression/torsion during the transit back to port.  ..(snip)

2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.  ...(snip)

Surely you don't think SpaceX has overlooked these issues, do you?
This is not some half baked operation.
It will be interesting to see what they do to cope with these issues.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kch on 04/03/2016 06:56 pm
How hard is it to throw a tarp over the stage?


2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.   Corrosion mechanisms that were not a problem for single use launches could very well manifest themselves on landed stages subject to that environment.  The environment factors could compound the cyclic loading factors.   


If you can throw a tarp 170 feet or so straight up, you have one heck of a throwing arm!  ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Stan-1967 on 04/03/2016 07:11 pm
How hard is it to throw a tarp over the stage?


2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.   Corrosion mechanisms that were not a problem for single use launches could very well manifest themselves on landed stages subject to that environment.  The environment factors could compound the cyclic loading factors.   


If you can throw a tarp 170 feet or so straight up, you have one heck of a throwing arm!  ;)
A tarp will protect it from rain, but not from humidity, condensation, and some salt spray in the air. 

S1 stands some 47 meters tall.   Does the ASDS barge or the command ship have the euipment needed to access the top of the stage?   I don't think we know the answer to that.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Stan-1967 on 04/03/2016 07:16 pm
My WAG is that the stage will survive the journey back to port upright just fine, but I think there are other more dangerous unknowns that need to be characterized.

1.  The natural oscillation frequency of the barge, due to wave action, is going to be loading members & joints alternately between tension/compression/torsion during the transit back to port.  ..(snip)

2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.  ...(snip)

Surely you don't think SpaceX has overlooked these issues, do you?
This is not some half baked operation.
It will be interesting to see what they do to cope with these issues.

No, I don not think they are some half baked operation.  I do not think I was being disrespectful to their expertise by making the observations I did.  How far SpaceX has already taken this is completely unknown to me, is it know to you?

I do think SpaceX has some demonstrated a philosophical history of minimizing problems until reality demonstrates the need for greater attention.  They seem to go for the simple solutions before loading in more complexity, changes, & cost.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Coastal Ron on 04/03/2016 07:55 pm
I do think SpaceX has some demonstrated a philosophical history of minimizing problems until reality demonstrates the need for greater attention.

I don't see how anyone outside of SpaceX can prove that statement.  It's obviously your opinion, but I disagree with it.

Quote
They seem to go for the simple solutions before loading in more complexity, changes, & cost.

Show me an organization that always builds the most complex solution first and I'll show you an organization that is wasting time and money.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/03/2016 08:32 pm
I do think SpaceX has some demonstrated a philosophical history of minimizing problems until reality demonstrates the need for greater attention.

I don't see how anyone outside of SpaceX can prove that statement.  It's obviously your opinion, but I disagree with it.

Quote
They seem to go for the simple solutions before loading in more complexity, changes, & cost.

Show me an organization that always builds the most complex solution first and I'll show you an organization that is wasting time and money.

Should I start with ablative chamber for the engine, or parachute recovery of first stage...
In so many cases SpaceX started simple, to go more complicate if needed.
Not a bad thing...

As for the most complex solution, this site has the name of one of the big players.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Stan-1967 on 04/03/2016 11:30 pm
Well said Cambrianera.   It's been discussed in other threads, and commented by many here in this thread ( looking at you Coastal Ron  :D ) that SpaceX is balancing many priorities in regards to allocation of engineering resources.   

Where exactly do you think cyclic loading and corrosion mechanisms as a result of barge transport fit in with balancing engineering resources for FH, Raptor FFSC, a Raptor upper stage, Dragon V2 for cargo & crew, should I go on?

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 04/03/2016 11:46 pm
I do think SpaceX has some demonstrated a philosophical history of minimizing problems until reality demonstrates the need for greater attention.

I don't see how anyone outside of SpaceX can prove that statement.  It's obviously your opinion, but I disagree with it.

Quote
They seem to go for the simple solutions before loading in more complexity, changes, & cost.

Show me an organization that always builds the most complex solution first and I'll show you an organization that is wasting time and money.

Should I start with ablative chamber for the engine, or parachute recovery of first stage...
In so many cases SpaceX started simple, to go more complicate if needed.
Not a bad thing...

As for the most complex solution, this site has the name of one of the big players.

Great points.  I'll add that they are tagging on experiments and development on flights paid for by customers. 

It has started slow, but as they ramp up the pace of development should increase with flight rate and revenue growth. 

If you write down a list of everything they've accomplished in the last 10 years with a very low flight rate, then the expectation for the next 10 years should excite everyone!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nomadd on 04/04/2016 12:47 am
My WAG is that the stage will survive the journey back to port upright just fine, but I think there are other more dangerous unknowns that need to be characterized.

1.  The natural oscillation frequency of the barge, due to wave action, is going to be loading members & joints alternately between tension/compression/torsion during the transit back to port.  ..(snip)

2.  All of that cyclic loading is happening in a marine environment with significant humidity, ocean spray, and temperatures changes day to night & night to day on some journeys.  ...(snip)

Surely you don't think SpaceX has overlooked these issues, do you?
This is not some half baked operation.
It will be interesting to see what they do to cope with these issues.
You would have thought all of the problems SpaceX has had would have been thoroughly analyzed before they happened. Stan raised some well thought out questions and cliches about daring to question the competence of the gods don't really help. Problems don't usually occur because of highly difficult to foresee issues. They tend to occur because of really dumb things that people on this forum could very well pick up on. I've been on some pretty harrowing barge rides because of squalls that can't be predicted and make you think you're in a hurricane for a few minutes.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: guckyfan on 04/04/2016 12:57 am
I imagine, SpaceX are aware of a number of potential problems and prefer to wait until they come up to evaluate their extent. With tests done on commercial flight that approach may be easier,faster and cheaper than solving everything through analysis and extensive tests before the first flight.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: te_atl on 04/04/2016 01:37 am
I imagine, SpaceX are aware of a number of potential problems and prefer to wait until they come up to evaluate their extent. With tests done on commercial flight that approach may be easier,faster and cheaper than solving everything through analysis and extensive tests before the first flight.

I would revise that to be that SpaceX is aware of the potential problems, took their best judgement on what would be required to alleviate or avoid them and is waiting for actual data to prove or disprove their efforts as being effective.

I don't doubt they considered Stan's questions, but like him they are waiting for actual data to see the results of their efforts and what further measures if any they might have to take.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/04/2016 02:32 am
Quote
A tarp will protect it from rain, but not from humidity, condensation, and some salt spray in the air. 

US launch vehicle components are traditionally designed and qualified to the MIL-STD 810 "salt fog" test standard, because launching from the Cape or other coastal area requires tolerance of salt spray just sitting on the launch pad near the ocean. A few extra days on a barge is unlikely to do anything worse than the MIL-STD 810 test environments.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Stan-1967 on 04/04/2016 07:32 am
Quote
A tarp will protect it from rain, but not from humidity, condensation, and some salt spray in the air. 

US launch vehicle components are traditionally designed and qualified to the MIL-STD 810 "salt fog" test standard, because launching from the Cape or other coastal area requires tolerance of salt spray just sitting on the launch pad near the ocean. A few extra days on a barge is unlikely to do anything worse than the MIL-STD 810 test environments.

I do think MIL-Standards are a valuable reference point.  I have some experience with ASTM B-117 NSS testing on components for Boeing aircraft, not too different from MIL-STD 810 salt fog testing section.  Does the "810" spec test at the component or systems level?  ( component level I believe )   A rocket operates at a systems level and component level testing while certainly valuable, is not the end all be all.

The "810" spec is also predicated on the expected life cycle of the part.  I don't think there is any existing reference point for the life cycle conditions of a reusable EELV class rocket.  Life cycle for expendable rockets ends when the stage burns out.  It is that second ( and beyond) cycle that is moving the lifecycle of F9 into unknown territory. 

I don't think MIL-STD 810 as applied to new launch vehicle components is going to be helpful in being predictive of failure or risk in a reusable system.  Component level testing is ideal for baselining a performance standard, but I would wager that many key parts of the Orbcomm-2 core that was recovered would not pass the "810" salt fog test if removed from the vehicle and put into the test chamber.


This has wandered pretty far off topic for a CRS-8 discussion.  It started out talking about transport of the CRS-8 core, but is gone into reuse issues.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/04/2016 09:09 am
Quote
A tarp will protect it from rain, but not from humidity, condensation, and some salt spray in the air. 

US launch vehicle components are traditionally designed and qualified to the MIL-STD 810 "salt fog" test standard, because launching from the Cape or other coastal area requires tolerance of salt spray just sitting on the launch pad near the ocean. A few extra days on a barge is unlikely to do anything worse than the MIL-STD 810 test environments.

I do think MIL-Standards are a valuable reference point.  I have some experience with ASTM B-117 NSS testing on components for Boeing aircraft, not too different from MIL-STD 810 salt fog testing section.  Does the "810" spec test at the component or systems level?  ( component level I believe )   A rocket operates at a systems level and component level testing while certainly valuable, is not the end all be all.

Yes, and you make other valid points. But the main thing is, launch vehicle manufacturers are well aware of corrosion issues at coastal sites and do make special provisions for surviving that environment. MIL-STD 810 "salt fog" testing is one example of how that is done at a component level.. And SpaceX already got burned by a possibly-related issue on Falcon 1 and are unlikely to make the same mistake twice.

Quote
Why the nut cracked is still a bit of a mystery. Musk said the "prevailing thought" among investigators, which included a mix of government and SpaceX personnel, is that the heat and humidity on Omelek Island was a factor. Though the nut was anodized to guard against corrosion, Musk said, it may have been scratched at some point, compromising its protection against the elements. "We had a series of countdowns [during which] the rocket was exposed for quite a bit of time," Musk said. "And the vehicle hangar for about three months was not climate controlled."

http://www.space.com/2643-falcon-1-failure-traced-busted-nut.html
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: timverhoeven on 04/04/2016 11:11 am
Once S1 is standing vertically on the drone ship I've heard they will weld shoes over the legs. Will they then cruise back to shore like that? Wouldn't it be safer to translate horizontal? Can they not fit the gear they need for this? My next worry is that they will land but then have tipping problems on the trip back. Does anyone know details on these boots?

IIRC the same stands used after the Orbcom landing on shore to support the stage are also onboard the ASDS. I've seem then on picitures of previous ASDS missions. I presume that once the stage is secured these will be used  to fix and support the stage for ride to port.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 04/04/2016 04:23 pm
Once S1 is standing vertically on the drone ship I've heard they will weld shoes over the legs. Will they then cruise back to shore like that? Wouldn't it be safer to translate horizontal? Can they not fit the gear they need for this? My next worry is that they will land but then have tipping problems on the trip back. Does anyone know details on these boots?

IIRC the same stands used after the Orbcom landing on shore to support the stage are also onboard the ASDS. I've seem then on picitures of previous ASDS missions. I presume that once the stage is secured these will be used  to fix and support the stage for ride to port.

I've assumed there will also be some form of tie down from the base of the booster straight down to the ASDS.  That would help relieve load from the legs themselves.

The free body diagram of the booster, with it's mass, center of mass and hold down points and load per point(s) given any possible loads is very easy engineering.  Getting it back to port won't be hard. 

Getting it under bridges, that's the tough part.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: guyw on 04/04/2016 04:53 pm

Getting it under bridges, that's the tough part.

I think the move from Jacksonville to Port Canaveral solved that problem. From memory (always a bad thing to rely on) and a quick look at Google Maps, there are not any bridges in the way from the open sea to the Port Canaveral dock.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dorkmo on 04/04/2016 08:46 pm
they use aircraft jacks with custom attachment fixtures to attach to and hold the octoweb. on the barge i think these jacks will be welded to the deck. on the RTLS, the jacks were used and appeared to be weighted down by large concrete blocks. at the dock there are also taller mounts built that appear to attach to the same place as the jacks.

seems like they want to get the rocket off the landing legs relatively quickly after touchdown.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Flying Beaver on 04/05/2016 06:02 am
CRS - 8 Dragon from instagram (https://www.instagram.com/p/BDox4uLF8S6/).

It looks a bit... worn? Any chance this Dragon could have been refurbished from a previous mission?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 04/05/2016 06:13 am
CRS - 8 Dragon from instagram (https://www.instagram.com/p/BDox4uLF8S6/).

It looks a bit... worn? Any chance this Dragon could have been refurbished from a previous mission?

No.  As part of the CRS contract, NASA gets procured a new Dragon for each mission.  I imagine what you're seeing is just lighting/camera effects.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mikes on 04/05/2016 06:40 am
CRS - 8 Dragon from instagram (https://www.instagram.com/p/BDox4uLF8S6/).

It looks a bit... worn? Any chance this Dragon could have been refurbished from a previous mission?

No.  As part of the CRS contract, NASA gets procured a new Dragon for each mission.  I imagine what you're seeing is just lighting/camera effects.

It's also a quite heavily compressed image

$ identify -verbose 12940812_830072057119943_1446018063_n.jpg | grep Quality
  Quality: 72
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: QuantumG on 04/05/2016 06:55 am
Not only is there no requirement that CRS flights be all new Dragons (we go through this every launch and a few times between, how many more times?) but Gwynne Shotwell actually said they're expecting to fly their first recovered Dragon this year.

Quote from: Jeff Foust
Shotwell: hope to fly a recovered, refurbished Dragon later this year. - source (https://twitter.com/jeff_foust/status/694954313270038528) 4 Feb 2016


Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/05/2016 09:08 am
Not only is there no requirement that CRS flights be all new Dragons (we go through this every launch and a few times between, how many more times?) but Gwynne Shotwell actually said they're expecting to fly their first recovered Dragon this year.

Quote from: Jeff Foust
Shotwell: hope to fly a recovered, refurbished Dragon later this year. - source (https://twitter.com/jeff_foust/status/694954313270038528) 4 Feb 2016

On a CRS or a test flight?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: QuantumG on 04/05/2016 09:50 am
On a CRS or a test flight?

Dragon, not Dragon 2.


Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jacqmans on 04/05/2016 11:23 am
Some cargo info:

(HP press release)

NASA ships HP ZBook Workstations to the International Space Station.

4 April 2016

Today’s engineers, scientists, and designers push compute to the max, relying on uninterrupted performance to calculate a path to Mars,
design an airplane, contain a forest fire, or run Wall Street.

Where does this performance live? Some people think that the hardware is all the same, and that only the software matters. HP believes
that hardware powers the quality, performance, and reliability that can mean the difference between life or death.


Does that seem dramatic? Not to NASA (National Aeronautics and Space Administration), who’s running the ISS (International Space Station),

which sustains the human crews conducting crucial experiments beyond Earth’s atmosphere. ISS is a joint project with five space agencies,
including NASA, Roskosmos of Russia, Japan Aerospace Exploration Agency, Canadian Space Agency, and European Space Agency. In this orbiting
laboratory, six people live and work, spending much of their time demonstrating new technologies and conducting research not possible on Earth. 

The computers on ISS are refreshed every six years, and over the course of this year NASA will be replacing Lenovo laptops
with HP ZBook 15 Mobile Workstations. The Z Workstations are literally mission critical, tied in to ISS life support, vehicle control,
maintenance, and operations systems. They provide mission support for onboard experiments, email, entertainment, and more.

Why did NASA choose HP ZBook 15 Mobile Workstations? In part because they’re already proven: one has been in space for the last two years,
demonstrating the performance and reliability that HP builds into their mobile workstation solutions. With advanced capabilities that are
typically not available in notebooks, like 3D graphics, powerful processors, and massive memory, crew members can be a lot more efficient—and
even bootup times are scrutinized when an astronaut’s time is worth more than $100,000 an hour.


30 HP ZBook 15 Mobile Workstations will be heading to ISS from Cape Canaveral, Florida via the SpaceX Falcon 9 rocket on 8 April at 4:43pm EST.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: francesco nicoli on 04/05/2016 11:58 am
Not only is there no requirement that CRS flights be all new Dragons (we go through this every launch and a few times between, how many more times?) but Gwynne Shotwell actually said they're expecting to fly their first recovered Dragon this year.

Quote from: Jeff Foust
Shotwell: hope to fly a recovered, refurbished Dragon later this year. - source (https://twitter.com/jeff_foust/status/694954313270038528) 4 Feb 2016

that's a nice payload for the Falcon Heavy demo. You can send a Dragon to nice locations with a FH
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: QuantumG on 04/05/2016 12:02 pm
For God's sake.. three of us watched the video and commented on it at the time. There was no doubt what she was saying.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 04/05/2016 12:21 pm
Dragons are priced as new... not required to be new.  SpaceX has already reflown some reused parts.  QuantumG is correct.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/05/2016 12:35 pm
Some cargo info:

(HP press release)

NASA ships HP ZBook Workstations to the International Space Station.

4 April 2016

Today’s engineers, scientists, and designers push compute to the max, relying on uninterrupted performance to calculate a path to Mars,
design an airplane, contain a forest fire, or run Wall Street.

Where does this performance live? Some people think that the hardware is all the same, and that only the software matters. HP believes
that hardware powers the quality, performance, and reliability that can mean the difference between life or death.


Does that seem dramatic? Not to NASA (National Aeronautics and Space Administration), who’s running the ISS (International Space Station),

which sustains the human crews conducting crucial experiments beyond Earth’s atmosphere. ISS is a joint project with five space agencies,
including NASA, Roskosmos of Russia, Japan Aerospace Exploration Agency, Canadian Space Agency, and European Space Agency. In this orbiting
laboratory, six people live and work, spending much of their time demonstrating new technologies and conducting research not possible on Earth. 

The computers on ISS are refreshed every six years, and over the course of this year NASA will be replacing Lenovo laptops
with HP ZBook 15 Mobile Workstations. The Z Workstations are literally mission critical, tied in to ISS life support, vehicle control,
maintenance, and operations systems. They provide mission support for onboard experiments, email, entertainment, and more.

Why did NASA choose HP ZBook 15 Mobile Workstations? In part because they’re already proven: one has been in space for the last two years,
demonstrating the performance and reliability that HP builds into their mobile workstation solutions. With advanced capabilities that are
typically not available in notebooks, like 3D graphics, powerful processors, and massive memory, crew members can be a lot more efficient—and
even bootup times are scrutinized when an astronaut’s time is worth more than $100,000 an hour.



30 HP ZBook 15 Mobile Workstations will be heading to ISS from Cape Canaveral, Florida via the SpaceX Falcon 9 rocket on 8 April at 4:43pm EST.

Ack. As an I.T. guy myself, that read like an ostentatious advertisement. Sounds like someone won a new contract, given that Lenovo's units have been up there for years and years. The "advanced features that are typically not found in notebooks" line is particularly weird since you can find any of that technology in many other brands--just not the inexpensive ones.

These HP units are still commercial off-the-shelf units with some modifications, right? Are they radiation-hardened processors or modified in any particular way for ISS use? I know there's a current experiment to test radiation tolerance now aboard (http://www.nasa.gov/mission_pages/station/research/experiments/2046.html). Are they still using a Linux (http://spaceref.com/iss/computer/), such as Debian?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 04/05/2016 12:37 pm

Ack. As an I.T. guy myself, that read like an ostentatious advertisement. Sounds like someone won a new contract, g

What part of "HP press release" didn't you understand?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: whitelancer64 on 04/05/2016 03:18 pm
Article ahead of the Static Fire later today - by Chris Gebhardt:
https://www.nasaspaceflight.com/2016/04/spacex-falcon-9-static-fire-crs-8-mission/

The only issue I have with the article is that it describes the ASDS distance downrange in nautical miles.

"For this, the ASDS will be placed approximately 185 nautical miles Northeast of the launch site where it will wait to receive the Falcon 9 first stage."

I assume that the unit is in the original NOTAM advisory, but can we please use or include standard miles and / or kilometers in the article? Not everyone is aware that nautical miles are different from standard miles, 185 NM = 212.89 mi = 342.62 km
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/05/2016 04:11 pm

Ack. As an I.T. guy myself, that read like an ostentatious advertisement. Sounds like someone won a new contract, g

What part of "HP press release" didn't you understand?

The "HP" part. I'm so used to NASA press releases here and missed that entirely.

Notes to self: Don't tug on Superman's cape, spit in the wind, pull the mask off the Long Ranger, or miss around with Jim...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 04/05/2016 05:33 pm


The "HP" part. I'm so used to NASA press releases here and missed that entirely.

Notes to self: Don't tug on Superman's cape, spit in the wind, pull the mask off the Long Ranger, or miss a round with Jim...

There fixed your typo ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chris Bergin on 04/05/2016 06:51 pm
Article ahead of the Static Fire later today - by Chris Gebhardt:
https://www.nasaspaceflight.com/2016/04/spacex-falcon-9-static-fire-crs-8-mission/

The only issue I have with the article is that it describes the ASDS distance downrange in nautical miles.

"For this, the ASDS will be placed approximately 185 nautical miles Northeast of the launch site where it will wait to receive the Falcon 9 first stage."

I assume that the unit is in the original NOTAM advisory, but can we please use or include standard miles and / or kilometers in the article? Not everyone is aware that nautical miles are different from standard miles, 185 NM = 212.89 mi = 342.62 km

The only issue I had with this post is it was in the update thread   :P

Anyway, fair point, well made. I've edited it to "approximately 210 miles".

PS To all: It's a lot faster to PM me (as editor) and/or the writer as I only saw this message three hours later.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: whitelancer64 on 04/05/2016 07:10 pm
The only issue I had with this post is it was in the update thread   :P

Anyway, fair point, well made. I've edited it to "approximately 210 miles".

PS To all: It's a lot faster to PM me (as editor) and/or the writer as I only saw this message three hours later.

Opps I thought it was the Discussion thread. My bad. Thanks for listening to the input, though!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: enzo on 04/06/2016 01:13 am
About an hour remaining in the Static Fire window. Still pressing for an attempt.
Noob question, does "pressing for an attempt" literally mean keeping the tanks pressurized, or is it merely a metaphor, as in "The slogan Press On! has solved and always will solve the problems of the human race." ?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/06/2016 01:15 am
About an hour remaining in the Static Fire window. Still pressing for an attempt.
Noob question, does "pressing for an attempt" literally mean keeping the tanks pressurized, or is it merely a metaphor, as in "The slogan Press On! has solved and always will solve the problems of the human race." ?

Metaphor. As in, Keep Calm and Press On.

But you may hear "tanks pressing" on the launch webcast, which does mean pressurizing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Johnnyhinbos on 04/06/2016 02:08 am
From SpaceX:

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: gongora on 04/06/2016 02:18 am
Not only is there no requirement that CRS flights be all new Dragons (we go through this every launch and a few times between, how many more times?) but Gwynne Shotwell actually said they're expecting to fly their first recovered Dragon this year.

Quote from: Jeff Foust
Shotwell: hope to fly a recovered, refurbished Dragon later this year. - source (https://twitter.com/jeff_foust/status/694954313270038528) 4 Feb 2016

From what we've previously heard the refurbished Dragons will have been stripped down to the pressure vessel and given a new outer layer, so when it happens it won't look any different than a new Dragon.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 04/06/2016 03:01 am
CRS - 8 Dragon from instagram (https://www.instagram.com/p/BDox4uLF8S6/).

It looks a bit... worn? Any chance this Dragon could have been refurbished from a previous mission?

No.  As part of the CRS contract, NASA gets procured a new Dragon for each mission.  I imagine what you're seeing is just lighting/camera effects.
Another oft-repeated myth. Please either stop spreading it or provide an official (not 3rd-party) source. SpaceX has already reused parts of Dragon and plan to soon reuse a Dragon itself.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: HVM on 04/06/2016 07:59 am
https://www.youtube.com/watch?v=nGzf68XJLyw

What's up with the flying "cinder"? I don't remember seeing those in other Static Fire videos.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: NovaSilisko on 04/06/2016 08:03 am
In the video of the static fire, you can see the odd spectacle of a few chunks of white-hot something-or-other go flying out of the flame trench after the burn. I wonder what they were. Don't think I've seen it in a static fire video before?

Edit: Hmph, beaten to the punch by HVM because I took so long grabbing nice screencaps  ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/06/2016 08:06 am
Perhaps a bit morbid but the first thought I had was small animals, maybe some birds were in the trench? Might be a good idea for flash cooking chicken, or a terrible idea.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: NovaSilisko on 04/06/2016 08:08 am
Perhaps a bit morbid but the first thought I had was small animals, maybe some birds were in the trench? Might be a good idea for flash cooking chicken, or a terrible idea.

I... don't believe a bird would retain structural integrity for such a length of time after being hit with rocket exhaust.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joaosg on 04/06/2016 08:36 am
Perhaps a bit morbid but the first thought I had was small animals, maybe some birds were in the trench? Might be a good idea for flash cooking chicken, or a terrible idea.

I... don't believe a bird would retain structural integrity for such a length of time after being hit with rocket exhaust.

RUD of the bird right? :) (or :( , i'm not sure)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kamilfredo on 04/06/2016 09:07 am
this static fire were little bit longer than usual .... perhaps to 8s?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 04/06/2016 10:06 am
this static fire were little bit longer than usual .... perhaps to 8s?
Dunno about the eight seconds, but I agree: it seemed much longer than the usual test.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/06/2016 10:47 am
With things going all-out for a launch on Friday, when does it stop being 'NET 4/8/16'? After the post-Static Fire review?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/06/2016 11:09 am
What's up with the flying "cinder"? I don't remember seeing those in other Static Fire videos.

Maybe not in static fire videos, but incandescent stuff was seen flying out of the trench in a couple occasions during an actual launch.

There's also the observational bias angle, stuff like this is more noticeable during nighttime.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jcc on 04/06/2016 11:14 am
With things going all-out for a launch on Friday, when does it stop being 'NET 4/8/16'? After the post-Static Fire review?

When they actually launch. The backup date is 4/9.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mvpel on 04/06/2016 11:59 am
With things going all-out for a launch on Friday, when does it stop being 'NET 4/8/16'? After the post-Static Fire review?
There's a meeting called a Launch Readiness Review where they get together all the people in charge of all the critical paths, including the static fire test, and make sure everyone's go for launch.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AJW on 04/06/2016 02:31 pm
In the video of the static fire, you can see the odd spectacle of a few chunks of white-hot something-or-other go flying out of the flame trench after the burn. I wonder what they were. Don't think I've seen it in a static fire video before?

Perhaps these were unicorns gathered together for a dance.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/06/2016 02:46 pm
The usual suspects are loose chunks of concrete or brick liberated from the trench by the blast, or "dirty water" which happens to catch the light.  Any opinions about whether one of these usual suspects could be guilty in this case?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/06/2016 03:30 pm
What caught my eye is that the debris & steam cloud, at its furthest point, drifted through a green-shaded light and looked like a green chemical. At first I thought it was something specifically associated with the igniters but, as it persisted for several seconds, I realised it was just a lighting effect.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CraigLieb on 04/06/2016 03:31 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: edkyle99 on 04/06/2016 06:11 pm
Article ahead of the Static Fire later today - by Chris Gebhardt:
https://www.nasaspaceflight.com/2016/04/spacex-falcon-9-static-fire-crs-8-mission/

The only issue I have with the article is that it describes the ASDS distance downrange in nautical miles.

"For this, the ASDS will be placed approximately 185 nautical miles Northeast of the launch site where it will wait to receive the Falcon 9 first stage."

I assume that the unit is in the original NOTAM advisory, but can we please use or include standard miles and / or kilometers in the article? Not everyone is aware that nautical miles are different from standard miles, 185 NM = 212.89 mi = 342.62 km

The only issue I had with this post is it was in the update thread   :P

Anyway, fair point, well made. I've edited it to "approximately 210 miles".

PS To all: It's a lot faster to PM me (as editor) and/or the writer as I only saw this message three hours later.
OK, now it is my turn to post an annoying complaint!  Since NASA and the USAF use "nautical miles", any mention of "miles" should specify either "nautical" or "statute" to avoid confusion.  Or, just use kilometers. 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Brian45 on 04/06/2016 06:29 pm
Do other launch companies do these static fire tests? Is it just because I'm a fan of SpaceX and that's all I hear about?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Pete on 04/06/2016 06:51 pm

OK, now it is my turn to post an annoying complaint!  Since NASA and the USAF use "nautical miles", any mention of "miles" should specify either "nautical" or "statute" to avoid confusion.  Or, just use kilometers. 

 - Ed Kyle

There's no reason to get confused with the size of your Miles.
a Nautical mile is 6,080.2 feet
An International Mile is 5,280 feet
a Statute Mile is 5,280 survey feet, which makes it 33/125 of a barleycorn longer than the International mile.

Its all quite easy, really.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ohsin on 04/06/2016 06:55 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.

This one was released and later removed by SpaceX employee after 14 July 2014 (Flight 10, OG1 mission)

Edit: Original link (http://i.imgur.com/mOhkTCb.jpg)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/06/2016 07:02 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.

This one was released and later removed by SpaceX employee after 14 July 2014 (Flight 10, OG1 mission)

Given that few other birds fly at the height that this particular Falcon can go, I'd say we missed our opportunity for some flash-roasted Turkey Vulture. And I had the gravy all ready. Sad and humorous all at once. We occasionally forget that the Cape is also a natural wildlife reserve.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mike_1179 on 04/06/2016 07:27 pm
Do other launch companies do these static fire tests? Is it just because I'm a fan of SpaceX and that's all I hear about?


Both the Atlas and Delta do a wet dress rehearsal a few days before launch. This involves taking the countdown almost to ignition but not quite to test the vehicle and the ground support equipment. They have pretty high confidence in their systems that they don't need to test that engines ignite and perform as appropriate when integrated to the vehicle before using them for real.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vulture4 on 04/06/2016 07:54 pm
For the Shuttles a 20-second Flight Readiness Firing of the main engines was done before the first launch of a new Shuttle but not routinely. Naturally the solid fuel boosters could not be tested.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: whitelancer64 on 04/06/2016 08:33 pm
Early in its flight history the Delta IV did some on pad, hold down, hot fire tests (Flight Readiness Firings) on the pad prior to launch, but they are not done on a regular basis.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: boog on 04/06/2016 08:48 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.

This one was released and later removed by SpaceX employee after 14 July 2014 (Flight 10, OG1 mission)

Edit: Original link (http://i.imgur.com/mOhkTCb.jpg)

It looks like that thing ignited before it even got to the engines, why? The force of impacting the bird (?) was enough to spontaneously combust it? Crazy if true?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/06/2016 09:00 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.

This one was released and later removed by SpaceX employee after 14 July 2014 (Flight 10, OG1 mission)

Edit: Original link (http://i.imgur.com/mOhkTCb.jpg)

It looks like that thing ignited before it even got to the engines, why? The force of impacting the bird (?) was enough to spontaneously combust it? Crazy if true?

More likely the heat of the expanding exhaust plume that appears to move forward from the engine nozzles. The bird was cooking about halfway and was ready to eat milliseconds before it reached the nozzles.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Bynaus on 04/06/2016 09:12 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.

This one was released and later removed by SpaceX employee after 14 July 2014 (Flight 10, OG1 mission)

Edit: Original link (http://i.imgur.com/mOhkTCb.jpg)

It looks like that thing ignited before it even got to the engines, why? The force of impacting the bird (?) was enough to spontaneously combust it? Crazy if true?

More likely the heat of the expanding exhaust plume that appears to move forward from the engine nozzles. The bird was cooking about halfway and was ready to eat milliseconds before it reached the nozzles.

Or it's just illumination. If you see how the starting engines can light up the smoke cloud...

Except for the last image in the sequence. That is combustion.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: boog on 04/06/2016 09:59 pm
just reminds me of that frog ejected during the launch. I imagine there is much that doesn't get seen by the cameras.

This one was released and later removed by SpaceX employee after 14 July 2014 (Flight 10, OG1 mission)

Edit: Original link (http://i.imgur.com/mOhkTCb.jpg)

It looks like that thing ignited before it even got to the engines, why? The force of impacting the bird (?) was enough to spontaneously combust it? Crazy if true?

More likely the heat of the expanding exhaust plume that appears to move forward from the engine nozzles. The bird was cooking about halfway and was ready to eat milliseconds before it reached the nozzles.

I buy heat from exhaust plume, still crazy. Could be illumination but looks like flames to me.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jcm on 04/06/2016 10:03 pm

OK, now it is my turn to post an annoying complaint!  Since NASA and the USAF use "nautical miles", any mention of "miles" should specify either "nautical" or "statute" to avoid confusion.  Or, just use kilometers. 

 - Ed Kyle

There's no reason to get confused with the size of your Miles.
a Nautical mile is 6,080.2 feet
An International Mile is 5,280 feet
a Statute Mile is 5,280 survey feet, which makes it 33/125 of a barleycorn longer than the International mile.

Its all quite easy, really.


Yes, but if the statement you're trying to parse just says "miles", and the same agency sometimes uses
statute and sometimes nautical (sometimes both in coverage of the same launch for height vs range), there's no way to be sure which is meant.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jdeshetler on 04/07/2016 12:01 am
Close up & stabilized for your analysis, by the way, that's a nice arc.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 04/07/2016 12:34 am

OK, now it is my turn to post an annoying complaint!  Since NASA and the USAF use "nautical miles", any mention of "miles" should specify either "nautical" or "statute" to avoid confusion.  Or, just use kilometers. 

 - Ed Kyle

There's no reason to get confused with the size of your Miles.
a Nautical mile is 6,080.2 feet
An International Mile is 5,280 feet
a Statute Mile is 5,280 survey feet, which makes it 33/125 of a barleycorn longer than the International mile.

Its all quite easy, really.


Yes, but if the statement you're trying to parse just says "miles", and the same agency sometimes uses
statute and sometimes nautical (sometimes both in coverage of the same launch for height vs range), there's no way to be sure which is meant.

If America, like the rest of the world used Metric then meters ad kilometers would prevent such arguments over how many length of King George's foot are in a mile.

Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Brian45 on 04/07/2016 03:33 am
So on the static fire issue, would we expect to have these tests eventually go away as confidence in the vehicle increases?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/07/2016 04:09 am

OK, now it is my turn to post an annoying complaint!  Since NASA and the USAF use "nautical miles", any mention of "miles" should specify either "nautical" or "statute" to avoid confusion.  Or, just use kilometers. 

 - Ed Kyle

There's no reason to get confused with the size of your Miles.
a Nautical mile is 6,080.2 feet
An International Mile is 5,280 feet
a Statute Mile is 5,280 survey feet, which makes it 33/125 of a barleycorn longer than the International mile.

Its all quite easy, really.


Yes, but if the statement you're trying to parse just says "miles", and the same agency sometimes uses
statute and sometimes nautical (sometimes both in coverage of the same launch for height vs range), there's no way to be sure which is meant.

If America, like the rest of the world used Metric then meters ad kilometers would prevent such arguments over how many length of King George's foot are in a mile.

Unfortunately, it's never going to be that simple.  The best you could do is maybe Metric (on-land) plus Nautical Miles (off-land), because, by definition and common usage, a Nautical Mile implies more than mere distance - it equals a minute of lattitude (north-south) - and that's key to all navigation off of the dirt beneath your feet.
 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Sesquipedalian on 04/07/2016 04:45 am
Unfortunately, it's never going to be that simple.  The best you could do is maybe Metric (on-land) plus Nautical Miles (off-land), because, by definition and common usage, a Nautical Mile implies more than mere distance - it equals a minute of lattitude (north-south) - and that's key to all navigation off of the dirt beneath your feet.

We should settle this by standardizing on nautical kilometers.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jcm on 04/07/2016 04:46 am

OK, now it is my turn to post an annoying complaint!  Since NASA and the USAF use "nautical miles", any mention of "miles" should specify either "nautical" or "statute" to avoid confusion.  Or, just use kilometers. 

 - Ed Kyle

There's no reason to get confused with the size of your Miles.
a Nautical mile is 6,080.2 feet
An International Mile is 5,280 feet
a Statute Mile is 5,280 survey feet, which makes it 33/125 of a barleycorn longer than the International mile.

Its all quite easy, really.


Yes, but if the statement you're trying to parse just says "miles", and the same agency sometimes uses
statute and sometimes nautical (sometimes both in coverage of the same launch for height vs range), there's no way to be sure which is meant.

If America, like the rest of the world used Metric then meters ad kilometers would prevent such arguments over how many length of King George's foot are in a mile.

Unfortunately, it's never going to be that simple.  The best you could do is maybe Metric (on-land) plus Nautical Miles (off-land), because, by definition and common usage, a Nautical Mile implies more than mere distance - it equals a minute of lattitude (north-south) - and that's key to all navigation off of the dirt beneath your feet.
 

You could switch to radians or great circles. 40000 km = 1 great circle.   1 km = pi / 20000  radians.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/07/2016 05:38 am
You could switch to radians or great circles. 40000 km = 1 great circle.   1 km = pi / 20000  radians.

A nice idea.. but saying that, for example, your orbit is "one-and-a-bit great circles" high just might not be precise enough for most people.  ;D
 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Pete on 04/07/2016 06:00 am
Close up & stabilized for your analysis, by the way, that's a nice arc.

Considering that whatever that flaming bit is, it gets thrown in an arc more than 80 meters high.
It has to be something of significant mass and density. No mere flaming Sparrow or Frog will fly that high.

Its unlikely to be a brick,concrete or similar, such rapid heating would shred it

Its could be a metal fitting that was right in the flame, but would that result is such nice "dribbles" of flame falling off?

My bet is that it was a badly-placed camera. Suitable mass and density, nice mix of heat-surviving metal bits and dribbly plastic parts, plus it has a reasonable excuse to be so near the path of danger.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mike_1179 on 04/07/2016 07:15 am
Refractory bricks shot out pretty far of the flame trench for shuttle back in the day. I wouldn't be so quick to assume it's something other then flame trench wall material
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: woods170 on 04/07/2016 08:32 am

Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.
Don't underestimate the ability of the members here to discuss things ad nauseum, even in a very limited amount of time.  ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: woods170 on 04/07/2016 08:34 am
Refractory bricks shot out pretty far of the flame trench for shuttle back in the day. I wouldn't be so quick to assume it's something other then flame trench wall material
Refractory bricks and other general flame trench materials usually don't burn while on their way out...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: eeergo on 04/07/2016 09:19 am
You guys realize it happens in many other launchers' pads right?

See Proton (0:12-0:15s in the first video), CZ family (0:19 in the second video) and others...

https://www.youtube.com/watch?v=XJEV6s-3nTs

https://www.youtube.com/watch?v=0L5s6Nuk9pA
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jacqmans on 04/07/2016 10:03 am
Quote


Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.

SpaceX will never ever launch once a week....
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/07/2016 10:29 am
Unless some space application comes into existence that requires weekly launches (although I'm at a loss to speculate what such a thing could be). Speculation would be entirely off-topic.

Going back to the topic, anyone remember space-bat? The poor thing was stuck on the side of a shuttle's ET and thus got to experience 3g sustained acceleration and hypersonic airflow (although certainly not for very long).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/07/2016 11:50 am
Quote


Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.

SpaceX will never ever launch once a week....

"Heavier-than-air flying machines are impossible." -- Lord Kelvin, President, Royal Society, 1895
"Man will never reach the moon regardless of all future scientific advances." -- Dr. Lee De Forest, inventor of the Audion tube and a father of radio, 25 February, 1967.

Never is a long time - from now to the heat death of the universe. I'm always cautious when using the word "never".
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 04/07/2016 11:53 am

Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.
Don't underestimate the ability of the members here to discuss things ad nauseum, even in a very limited amount of time.  ;)

And with a very limited amount of information to go on. ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: eriblo on 04/07/2016 12:27 pm
Refractory bricks shot out pretty far of the flame trench for shuttle back in the day. I wouldn't be so quick to assume it's something other then flame trench wall material
Refractory bricks and other general flame trench materials usually don't burn while on their way out...
Dousing them in rocket fuel first can make for a convincing approximation :) It might also mostly be reflected light, hard to tell.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jet Black on 04/07/2016 01:20 pm
Refractory bricks shot out pretty far of the flame trench for shuttle back in the day. I wouldn't be so quick to assume it's something other then flame trench wall material
Refractory bricks and other general flame trench materials usually don't burn while on their way out...
Dousing them in rocket fuel first can make for a convincing approximation :) It might also mostly be reflected light, hard to tell.

or even just disintegration of something that is very hot.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: WHAP on 04/07/2016 02:50 pm
Especially when quickly veering off topic to discu

Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.
Don't underestimate the ability of the members here to discuss things ad nauseum, even in a very limited amount of time.  ;)

And with a very limited amount of information to go on. ;)

And with no regard for the actual topic at hand. 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Okie_Steve on 04/07/2016 02:56 pm
No mere flaming Sparrow or Frog will fly that high.
Depends on whether it's an African or Europen Sparrow.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/07/2016 03:21 pm
No mere flaming Sparrow or Frog will fly that high.
Depends on whether it's an African or Europen Sparrow.
or and African or Asian rhinoceros.....
My goodness, people!  On and on and on
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/07/2016 03:24 pm
So on the static fire issue, would we expect to have these tests eventually go away as confidence in the vehicle increases?
All indications are that SpaceX considers it a standard part of their pre-launch flow and an important "competitive advantage" -- that is, they believe the all-up test improves reliability.

Of course, they could always change their minds later.  Presumably once static fires become so routine and trouble free that they've stopped learning anything interesting from them.

But I wouldn't expect a change this year.  Or next.  After that, who knows?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: garcianc on 04/07/2016 03:51 pm
So on the static fire issue, would we expect to have these tests eventually go away as confidence in the vehicle increases?

I don't believe so, but I am sure someone will tell me if I am wrong.

The "test like you fly, test what you fly" doctrine is deeply embedded in SpaceX's engineering philosophy: https://www.aiaa.org/uploadedFiles/Events/Conferences/2012_Conferences/2012-Complex-Aerospace-Systems-Exchange-Event/Detailed_Program/CASE2012_2-4_Muratore_presentation.pdf (https://www.aiaa.org/uploadedFiles/Events/Conferences/2012_Conferences/2012-Complex-Aerospace-Systems-Exchange-Event/Detailed_Program/CASE2012_2-4_Muratore_presentation.pdf).
The NASA Systems Engineering approach and project management philosophy also support that (and precede it): http://www.nasa.gov/pdf/423715main_NPR_7120-5_HB_FINAL-02-25-10.pdf (http://www.nasa.gov/pdf/423715main_NPR_7120-5_HB_FINAL-02-25-10.pdf)

I am not even getting into safety codes and regulations. I am not smart enough on the subject, but can assume that those are non-negotiable.

Edit: cscott beat me to the punch. Darn broken finger...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JoerTex on 04/07/2016 03:56 pm
Do other launch companies do these static fire tests? Is it just because I'm a fan of SpaceX and that's all I hear about?


Both the Atlas and Delta do a wet dress rehearsal a few days before launch. This involves taking the countdown almost to ignition but not quite to test the vehicle and the ground support equipment. They have pretty high confidence in their systems that they don't need to test that engines ignite and perform as appropriate when integrated to the vehicle before using them for real.

Remember, the Merlins are designed for reuse and are much more robust in construction that other engines.  The static fire isn't a concern from time on the engine.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: bunker9603 on 04/07/2016 04:14 pm
Quote


Edit:  However, if SpaceX flew once a week we wouldn't have time to discuss such trivia.

SpaceX will never ever launch once a week....


Like someone said above, "Never" is a long time and unless you have a time machine an have read history books from the future there is no way to know for sure.... a lot can change in just 5-10 years
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: spacenut on 04/07/2016 04:27 pm
Well, SpaceX has pad 40 in operation for Falcon 9 now.  They are getting pad 39 ready for Falcon 9 humans and Falcon Heavies.  They are building a site at Boca Chica, Texas.  They also have a pad at Vandenburg for polar orbits.  That is 4 pads coming on line.  So, they only launch once a month at each pad, that is once a week launch.  Never say never. 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lar on 04/07/2016 05:07 pm
I'm  not the best mod.... (just ask anyone) but I kinda suspect that the following are off topic: Animal barbeque techniques. Flammability of bricks. Units of measure. Launch frequency. Speculation frequency and focus. (and a fair few I missed)

Say no more, wink wink, nudge nudge.  Or else I'll tell your father.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rower2000 on 04/07/2016 05:40 pm
No mere flaming Sparrow or Frog will fly that high.
You sure?
(https://upload.wikimedia.org/wikipedia/commons/thumb/8/8e/AIM-7_Sparrow_at_Eglin_AFB_1988.JPEG/1200px-AIM-7_Sparrow_at_Eglin_AFB_1988.JPEG)
 ;D.

Image is public domain, USAF.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nomadd on 04/07/2016 05:44 pm
 I know this has probably been covered, but with the 3,000 lb BEAM, this would be the most total payload by SpaceX to the ISS by a good margin, wouldn't it?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mvpel on 04/07/2016 05:50 pm
Would this also be the first time three cargo ships are berthed?


Sent from my iPhone using Tapatalk
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 04/07/2016 06:00 pm
jeff_foust: Robert Bigelow: BEAM has been bound up for more than a year awaiting launch. We’re not 100% sure of its behavior once in space.
https://twitter.com/jeff_foust/status/718135100966195201
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/07/2016 06:10 pm
Would this also be the first time three cargo ships are berthed?


Sent from my iPhone using Tapatalk
I suspect no. ORB missions usually take off before Dragons arrive and vice versa. I can't recall if you can have a Progress docked at the same time as the old ATV, and the HTV and Dragon have been up there at the same time. At the least, it'll tie the record (Progress, ATV/HTV/Cygnus, Soyuz, Soyuz, Dragon). And I think there was a time with two Progress docked at once, as well.

Hopefully someone with better resources than I have will be able to confirm this.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AnalogMan on 04/07/2016 06:16 pm
Would this also be the first time three cargo ships are berthed?

Sent from my iPhone using Tapatalk

There will be four cargo ships on station when Dragon berths (2 Progress, Cygnus) - plus two Soyuz  spacecraft.  This will tie for the most vehicles attached to the ISS at the same time (last happened in 2011).

http://www.nasa.gov/feature/dragon-and-cygnus-to-meet-for-first-time-in-space (http://www.nasa.gov/feature/dragon-and-cygnus-to-meet-for-first-time-in-space)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/07/2016 06:26 pm
Would this also be the first time three cargo ships are berthed?

Sent from my iPhone using Tapatalk

There will be four cargo ships on station when Dragon berths (2 Progress, Cygnus) - plus two Soyuz  spacecraft.  This will tie for the most vehicles attached to the ISS at the same time (last happened in 2011).

http://www.nasa.gov/feature/dragon-and-cygnus-to-meet-for-first-time-in-space (http://www.nasa.gov/feature/dragon-and-cygnus-to-meet-for-first-time-in-space)

Great find, thank you.

Looks like the only way to beat the six spacecraft record is once Commercial Crew flights add one more. My understanding is that it will unlikely that two CC would be up at the same time, especially not until both IDAs are installed. Or, if an HTV's arrival occurs while 2 Progress, a Cygnus and Dragon cargo are up.

We have the happy problem of an imminent "traffic jam."
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CuddlyRocket on 04/07/2016 06:44 pm
I'm  not the best mod.... (just ask anyone) ....

Better than I was; at least you weren't summarily dismissed! :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 04/07/2016 07:18 pm
There will be four cargo ships on station when Dragon berths (2 Progress, Cygnus) - plus two Soyuz  spacecraft.  This will tie for the most vehicles attached to the ISS at the same time (last happened in 2011).
Specifically, February 26th 2011 (ref: http://historicspacecraft.com/ISS.html):
Quote
With the arrival of STS-133 on February 26, 2011, a record six vehicles were at the station simultaneously (illustration below). In addition to Space Shuttle Discovery, three Russian spacecraft included Soyuz TMA-01M, Soyuz TMA-20 and Progress M-09M were docked to the station. A Japanese H-II Transfer Vehicle (HTV-2), and a European Automated Transfer Vehicle (ATV-2), were also at the station.
(http://historicspacecraft.com/Diagrams/S/ISS_Visiting_Vehicles_Feb2011_RK2011.jpg)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Sam Ho on 04/07/2016 07:45 pm
Another way to look at it is to count the available ports. 4 SSVP, 2 CBM, and 2 APAS. Up till this week, only 1 VV has berthed to CBM at a time. The APAS (soon to be IDSS) have never been used simultaneously, and have only been used by Shuttle. Thus, 6 VV during STS-133, and soon 6 VV with dual-CBM operations. 7 VV will require an IDSS VV docking.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: starhawk92 on 04/07/2016 08:00 pm
Can we please count BEAM as "docked" and set a record for ships at the station this round????

Can we rename it Babylon 5 now (or 1)?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/07/2016 08:35 pm
jeff_foust: Robert Bigelow: BEAM has been bound up for more than a year awaiting launch. We’re not 100% sure of its behavior once in space.
https://twitter.com/jeff_foust/status/718135100966195201

Okay, that sets a new all-time record for 'CRS pre-mission statements that do not build confidence in the payload'.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 04/07/2016 10:50 pm
jeff_foust: Robert Bigelow: BEAM has been bound up for more than a year awaiting launch. We’re not 100% sure of its behavior once in space.
https://twitter.com/jeff_foust/status/718135100966195201

Okay, that sets a new all-time record for 'CRS pre-mission statements that do not build confidence in the payload'.

Maybe that is the reason why NASA decided to pressurize/inflate the BEAM using ISS's air supply instead of using the compressed air tank supplied by Bigelow?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kansan52 on 04/07/2016 11:33 pm
If memory serves, the tank was removed at NASA's request to reduce risk (compressed gas tank inside BEAM).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/08/2016 02:03 am
During the press conference, Hans confirmed that Dragon will be able to use its parachutes in an abort situation. They obtained FAA approval for Phase 1 and 2 but not for Phase 3 (which is only the last 20 seconds).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yokem55 on 04/08/2016 02:13 am
During the press conference, Hans confirmed that Dragon will be able to use its parachutes in an abort situation. They obtained FAA approval for Phase 1 and 2 but not for Phase 3 (which is only the last 20 seconds).
Well, not so much as an abort, as much as it unexpectedly finds itself flying free during ascent...

Sent from my A0001 using Tapatalk

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/08/2016 02:27 am
If memory serves, the tank was removed at NASA's request to reduce risk (compressed gas tank inside BEAM).

Didn't they say during the press conference that BEAM would be carrying a tank of "makeup" air to fill the additional volume? IIRC, they even joked about it being "Nevada" air.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/08/2016 05:31 am
If memory serves, the tank was removed at NASA's request to reduce risk (compressed gas tank inside BEAM).

Didn't they say during the press conference that BEAM would be carrying a tank of "makeup" air to fill the additional volume? IIRC, they even joked about it being "Nevada" air.

FWIW, here's a NASA interview with the ISS project manager for BEAM confirming the same thing:
https://www.youtube.com/watch?v=TQHjWFFeetc
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/08/2016 05:52 am
FWIW, here's a NASA interview with the ISS project manager for BEAM confirming the same thing:
https://www.youtube.com/watch?v=TQHjWFFeetc (https://www.youtube.com/watch?v=TQHjWFFeetc)

Despite Mr Dasgupta's statement that NASA started inflatable work on Transhab in "the mid 1990's", they were working on it in the early 1960's.  A quick Google image search finds a completed 24' diameter test torus (http://www.nasa.gov/sites/default/files/space_station_1961-l-08693.jpeg) in 1961.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/08/2016 06:01 am
Despite Mr Dasgupta's statement that NASA started inflatable work on Transhab in "the mid 1990's", they were working on it in the early 1960's.  A quick Google image search finds a completed 24' diameter test torus (http://www.nasa.gov/sites/default/files/space_station_1961-l-08693.jpeg) in 1961.

Maybe he wasn't on the job back then.. :)
 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: NovaSilisko on 04/08/2016 07:39 am
Short kit  = reduced man hours to create the thing = lower baked in costs.

I feel like there are better ways to reduce the cost of spaceflight than cutting back on press kits...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: docmordrid on 04/08/2016 07:42 am
I agree, but having dealt with maddening bean counters for decades my first instinct is they had a say.

Let's also not forget that SpaceX just hired a new Comminications Director who may have his own ideas; Dex Torricke-Barton, former speechwriter for Zukerberg at Facebook.

Link.... (http://recode.net/2016/04/06/mark-zuckerberg-speechwriter-leaving-for-spacex-elon-musk/)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/08/2016 12:09 pm
I note that the landing is apparently planned for the barge (per Daily Mail website (http://www.dailymail.co.uk/sciencetech/article-3528687/Space-station-getting-inflatable-room-cosmic-1st.html)). If this is the case, two questions jump into my mind:

1) Is this because the mass of the BEAM leaves too little propellent margin for the boost back?

2) Given the difficulties SpaceX have been having, has any hint been given that they might abandon using the barge should they be unable to successfully land (or have consecutive successful landings) on it soon?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MattMason on 04/08/2016 12:20 pm
I note that the landing is apparently planned for the barge (per Daily Mail website (http://www.dailymail.co.uk/sciencetech/article-3528687/Space-station-getting-inflatable-room-cosmic-1st.html)). If this is the case, two questions jump into my mind:

1) Is this because the mass of the BEAM leaves too little propellent margin for the boost back?

2) Given the difficulties SpaceX have been having, has any hint been given that they might abandon using the barge should they be unable to successfully land (or have consecutive successful landings) on it soon?

Yesterday's pre-launch conference fielded these questions. The SpaceX representative, Hans Keonigsmann, said that they basically want to get ASDS landings perfected, often because there will be many future flights where LZ-1 landings of F9 stages would compromise the energy required to lift mission payloads to the correct orbit. There's also the implied point that multiple cores from a Falcon Heavy can't all return to LZ-1 as well. ASDS landings will always factor in all flights based on payload, and there will be times where boosters may not be recovered at all.

I believe that, according to the presser, the ASDS is closer to shore this time around, suggesting that the extra weight of BEAM isn't as much of a factor. If anyone can verify my notes here, that would be appreciated.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/08/2016 01:03 pm
I note that the landing is apparently planned for the barge (per Daily Mail website (http://www.dailymail.co.uk/sciencetech/article-3528687/Space-station-getting-inflatable-room-cosmic-1st.html)). If this is the case, two questions jump into my mind:

1) Is this because the mass of the BEAM leaves too little propellent margin for the boost back?

2) Given the difficulties SpaceX have been having, has any hint been given that they might abandon using the barge should they be unable to successfully land (or have consecutive successful landings) on it soon?

Pt2 is exactly why they want to do a barge landing. Practice makes perfect.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: litton4 on 04/08/2016 01:27 pm
Correct me if I'm wrong, but I don't think there was anything about the failed barge landings that were barge-related?

All of the 4 barge landing attempts would have failed on land, too.

1) Came in hot, no directional control (grid fins ran out of hydraulic fluid)
2) Came in hot, little directional control (sticky engine/TVC valve)
3) Came in perfectly, toppled over (leg didn't latch)
4) Came in incandescent, poked hole in barge (low thrust on one engine)

So, the barge appears to be concentrating on eliminating failure modes.......
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rik ISS-fan on 04/08/2016 01:51 pm
3) might have been a test for a planetary lander (Speculative)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Hauerg on 04/08/2016 02:00 pm
Correct me if I'm wrong, but I don't think there was anything about the failed barge landings that were barge-related?

All of the 4 barge landing attempts would have failed on land, too.

1) Came in hot, no directional control (grid fins ran out of hydraulic fluid)
2) Came in hot, little directional control (sticky engine/TVC valve)
3) Came in perfectly, toppled over (leg didn't latch)
4) Came in incandescent, poked hole in barge (low thrust on one engine)

So, the barge appears to be concentrating on eliminating failure modes.......

2) might have worked on land, since the final lateral movement would not have been necessary.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MarekCyzio on 04/08/2016 02:07 pm
Another picture of late loading taken earlier.

What is the purpose of these black bands on F9?

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/08/2016 02:10 pm
Another picture of late loading taken earlier.

What is the purpose of these black bands on F9?
Hmm, I don't recall seeing them before. They seem to be wrapped around to protect all the payload, stage and interstage connection points....from the salt and humidity?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Paul_G on 04/08/2016 02:13 pm
Another picture of late loading taken earlier.

What is the purpose of these black bands on F9?
Hmm, I don't recall seeing them before. They seem to be wrapped around all the payload, stage and interstage connection points.

Possibly to protect Grid Fins during roll out and erection?

Paul
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ElGuapoGuano1 on 04/08/2016 02:13 pm
So what do you guys think, what are the odds that Falcon 9 actually launches today? I'm usually pretty geared up and ready for a launch, but since the last launch had sooooo many scrubs. My confidence for a on time launch today is not high, IMHO my WAG says less than a 30% chance today even though the weather looks great.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/08/2016 02:16 pm
So what do you guys think, what are the odds that Falcon 9 actually launches today? I'm usually pretty geared up and ready for a launch, but since the last launch had sooooo many scrubs. My confidence for a on time launch today is not high, IMHO my WAG says less than a 30% chance today even though the weather looks great.
95%. I think they learned a lot from both the Orbcom and SES-9 launch campaigns.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ElGuapoGuano1 on 04/08/2016 02:31 pm
Really hope you are right rcoppola. Fingers crossed.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 04/08/2016 02:44 pm
So what do you guys think, what are the odds that Falcon 9 actually launches today? I'm usually pretty geared up and ready for a launch, but since the last launch had sooooo many scrubs. My confidence for a on time launch today is not high, IMHO my WAG says less than a 30% chance today even though the weather looks great.
95%. I think they learned a lot from both the Orbcom and SES-9 launch campaigns.

I'd guess 80%, they've had a good prelaunch flow and the weather looks good.  However, there are issues like a boat in the exclusion zone, range, ground side issue etc.

I feel good about today for both the launch and a vertical barge visitation.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/08/2016 03:02 pm
I think the odds are good. Weather is cooperative, mission is not novel and performance is not demanding, and teething pains seem to have been dealt with during the static fire.  On the other hand: instantaneous launch window.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dgates on 04/08/2016 03:02 pm
I am 50 miles west right now and weather is CAVU here.  Not a cloud anywhere.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: WindyCity on 04/08/2016 03:39 pm
Just checked weather.com. Winds projected to be 10-12 MPH at launch time. In the press conference, gusts of 20 MPH predicted.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dgates on 04/08/2016 03:51 pm
TAF and METAR for Titusville, roughly 10 miles west of launch site.


KTIX 081120Z 0812/0912 25008KT P6SM SCT250
  FM081400 27010KT P6SM SCT040
  FM081600 25012G21KT P6SM SCT050
  FM090000 26012KT P6SM SCT250

KTIX 081447Z 26007KT 7SM SKC 23/14 A2999
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/08/2016 04:06 pm
I think they stand very nice odds of going up today, glumming onto the side of ISS, and a large portion of it coming in to port standing up on ASDS OCISLY.  I think they have learned a lot about their propellant cooling apparatus and mostly have that understood and under control.  There were some here that were of the mind that if they were having such troubles with super cooled propellant in the last few launches then they would likely face semi-insurmountable difficulty in launching in the summer (not me).  From the perspective of that assertion we seem to be half way there today as the weather will be 80F and sunny.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 04/08/2016 04:27 pm
...
All of the 4 barge landing attempts would have failed on land, too.
...
2) Came in hot, little directional control (sticky engine/TVC valve)
...
So, the barge appears to be concentrating on eliminating failure modes.......
2) might have worked on land, since the final lateral movement would not have been necessary.
I'm fairly certain that the lateral movement was do to feedback/over-control control issue, it was not part of the intended flight.  So I don't think targeting the pad would have been any more likely to succeed assuming the same stiction issue.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: SamWiseCA on 04/08/2016 04:59 pm
Question about an image posted in the updates trhead
http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=39537.0,3Battach=1108741,3Bimage.pagespeed.ic.LmR6fbZWj0.webp (http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=39537.0,3Battach=1108741,3Bimage.pagespeed.ic.LmR6fbZWj0.webp)

There is some black something wrapped around the falcon in 2 locations while the rocket is laying down and being loaded.   Once erected this morning, that black item is gone.   What is it and what is it covering?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: schaban on 04/08/2016 05:54 pm
In SpaceX brief, MECO is at 150 sec. Wasn't it more like 180 seconds on prior flights?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: StarryKnight on 04/08/2016 05:58 pm
In SpaceX brief, MECO is at 150 sec. Wasn't it more like 180 seconds on prior flights?

Perhaps because of the higher thrust engines? IIRC the full thrust engines are supposed to provide ~15% more thrust. 15% of 180 seconds is 27 seconds, which gets you down to 150 seconds. Just guessing what it is here.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: manoweb on 04/08/2016 05:59 pm
According to my data:
CRS-1: 169
CRS-2: 169
CRS-3: 164
CRS-4: 164
CRS-5: 164
CRS-6: 161
CRS-7: n/a
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/08/2016 06:21 pm
When does NASA's webcast start?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/08/2016 06:23 pm
When does NASA's webcast start?

I found the answer. 3:30 pm.

http://www.nasa.gov/mission_pages/station/structure/launch/spacex.html
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: DiracsDelta on 04/08/2016 07:00 pm
Some cargo info:

(HP press release)

NASA ships HP ZBook Workstations to the International Space Station.

4 April 2016

Today’s engineers, scientists, and designers push compute to the max, relying on uninterrupted performance to calculate a path to Mars,
design an airplane, contain a forest fire, or run Wall Street.

Where does this performance live? Some people think that the hardware is all the same, and that only the software matters. HP believes
that hardware powers the quality, performance, and reliability that can mean the difference between life or death.


Does that seem dramatic? Not to NASA (National Aeronautics and Space Administration), who’s running the ISS (International Space Station),

which sustains the human crews conducting crucial experiments beyond Earth’s atmosphere. ISS is a joint project with five space agencies,
including NASA, Roskosmos of Russia, Japan Aerospace Exploration Agency, Canadian Space Agency, and European Space Agency. In this orbiting
laboratory, six people live and work, spending much of their time demonstrating new technologies and conducting research not possible on Earth. 

The computers on ISS are refreshed every six years, and over the course of this year NASA will be replacing Lenovo laptops
with HP ZBook 15 Mobile Workstations. The Z Workstations are literally mission critical, tied in to ISS life support, vehicle control,
maintenance, and operations systems. They provide mission support for onboard experiments, email, entertainment, and more.

Why did NASA choose HP ZBook 15 Mobile Workstations? In part because they’re already proven: one has been in space for the last two years,
demonstrating the performance and reliability that HP builds into their mobile workstation solutions. With advanced capabilities that are
typically not available in notebooks, like 3D graphics, powerful processors, and massive memory, crew members can be a lot more efficient—and
even bootup times are scrutinized when an astronaut’s time is worth more than $100,000 an hour.



30 HP ZBook 15 Mobile Workstations will be heading to ISS from Cape Canaveral, Florida via the SpaceX Falcon 9 rocket on 8 April at 4:43pm EST.

Ack. As an I.T. guy myself, that read like an ostentatious advertisement. Sounds like someone won a new contract, given that Lenovo's units have been up there for years and years. The "advanced features that are typically not found in notebooks" line is particularly weird since you can find any of that technology in many other brands--just not the inexpensive ones.

These HP units are still commercial off-the-shelf units with some modifications, right? Are they radiation-hardened processors or modified in any particular way for ISS use? I know there's a current experiment to test radiation tolerance now aboard (http://www.nasa.gov/mission_pages/station/research/experiments/2046.html). Are they still using a Linux (http://spaceref.com/iss/computer/), such as Debian?

To call the HP workstations "off the shelf" is a bit of an understatement. The mobile workstations typically incorporate much more testing and higher end components than are available to most consumers. some examples are: Server class processors, HUGE memory configs, pro graphics such as nvidia quadro, storage solutions that are ahead of the consumer market, and a huge modules and options list that allows you to pick from a much wider range of components. The biggest advantages are that they undergo much much more testing to cover the expanded modules list and are tested to a higher standard than any consumer devices.

 What makes the workstations specifically suited to the ISS, however, is the use of ECC memory which is resistant to bit flipping by cosmic rays and such. Obviously other manufacturers also produce workstations with some of these features, but I understand HP did some custom work in order to make sure the ZBooks would operate on the power requirements aboard the station.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mapperuo on 04/08/2016 07:49 pm
Wow those weather cloud graphics on NTV made me jump there...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 04/08/2016 07:50 pm
NASA webcast mentioned 1st stage recovery.  I did not see that coming, I thought they were pretty quiet about that since it's post mission.



Edit: Now that I think about it, I think we've seen landing criteria before.  So I guess it's not that unusual.  Still cool to hear a NASA webcast mention 1st stage recovery.  Exciting times.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ClayJar on 04/08/2016 08:12 pm
Has the procedure outside T-30 seconds always been to call "NO GO recommend hold" and have the LD or CE make the call?  (Inside T-30 for an anomaly that has a high risk of hardware damage, it's still the "HOLD HOLD HOLD" we all know and... um... love.)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 04/08/2016 08:12 pm
SpaceX is apparently not broadcasting until just a couple of minutes before launch.
Based on the count down on the stream, or additional information?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: docmordrid on 04/08/2016 08:14 pm
SpaceX ✔ ‎@SpaceX
Propellant load underway for Falcon 9. Launch webcast will go live in about 10 minutes http://www.spacex.com/webcast
4:08 PM - 8 Apr 2016
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 04/08/2016 08:14 pm
Has the procedure outside T-30 seconds always been to call "NO GO recommend hold" and have the LD or CE make the call?  (Inside T-30 for an anomaly that has a high risk of hardware damage, it's still the "HOLD HOLD HOLD" we all know and... um... love.)
That's a new variation to me - sounds like a sensible precaution against too precipitate a scrub.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: matthewkantar on 04/08/2016 08:15 pm
"initiating stage one helium cushion"
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: edkyle99 on 04/08/2016 08:16 pm
This is going to be the heaviest payload ever launched by a Falcon 9.  My guesstimate is nearly 10.4 metric tons.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: GregA on 04/08/2016 08:21 pm
L-2 hours. Always worth noting for people working through different timezones and need a marker.

Ahh thanks for that. I'd calculated wrong with daylight savings ending in Us and beginning here. Plus my Timezone settings on the site here are similarly wrong.

So 20 minutes now, will wake myself up!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/08/2016 08:25 pm
SpaceX webcast is live.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/08/2016 08:30 pm
SpaceX webcast running about 20 seconds ahead of the NASA feed?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: BioBritt on 04/08/2016 08:32 pm
SpaceX webcast running about 20 seconds ahead of the NASA feed?

Of course NASA removes their little time stamp right when you post that so I can't verify... :P

Edit: they just said 9:40 when SpaceX webcast was at 9:20, so yes, exactly!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: BioBritt on 04/08/2016 08:37 pm
Also the SpaceX technical webcast is about ten seconds ahead of the hosted webcast.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Zardar on 04/08/2016 08:37 pm
ISS just passed overhead in a clear sky at -8.4 deg W. What time will dragon be expected to transit at this location?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/08/2016 08:42 pm
Fair bit of pitching visible aboard OCISLY - but looks no worse than for JRTI / Jason 3.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ElGuapoGuano1 on 04/08/2016 08:50 pm
woohoo on the liftoff. I love it when I'm wrong!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: a_godumov on 04/08/2016 08:56 pm
Wow! Unbeliavable, the waves look pretty serious but it seems to be standing secure. And the approach angle looked too high in the beginning but it leveled just before the touchdown. Congratulations to SpaceX on this incredible achievement!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ulm_atms on 04/08/2016 08:59 pm
Well there is the data for stage stability on the barge(as long as the legs hold)......Them are not small waves and that boat be rocking!!!!

And that landing also bounced that barge quite a bit.

That was amazing to watch in real time.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: a_godumov on 04/08/2016 09:02 pm
I literally can't take my eyes off it. Now that they've demonstrated it works, investing in a bigger barge may be justified. I'm not sure it will be necessary though.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Hywel1995 on 04/08/2016 09:09 pm
OMG!! it worked... i'm crying with excitement
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sojourner on 04/08/2016 09:10 pm
Now to speculate on the fate of this stage. Dis-assembly? re-use? Testing?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: NovaSilisko on 04/08/2016 09:12 pm
Thank you Elon, thank you.

Well, I'm pretty sure he didn't do it on his own...

So: Congratulations to all of the hardworking people at SpaceX.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/08/2016 09:19 pm
Now to speculate on the fate of this stage. Dis-assembly? re-use? Testing?

Speculation?

It'll get a static fire at the Cape then shipped to Texas for more tests and possibly they'll re-fly it there.

If it survives that, I guess Orbcomm will be wanting to use it.

There are probably some developmental demands that might get in the way but I'd guess that the SpaceX will be keen to loft another satellite uphill on a re-used stage to prove they can do it - sooner rather than later.

As for the next one they manage to land on a barge, I wonder if they'll be ready to refuel it and try and fly it home - or whether that idea will be knocked on the head for a while? Costs are probably not dissimilar but the risk of losing it has to be quite significant in the thinking.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 04/08/2016 09:21 pm
Can't see that happening. They would have to have a full fuel rig (densified!) on the drone ship along with a full launch ground system. too much $$$.

Now to speculate on the fate of this stage. Dis-assembly? re-use? Testing?

...

As for the next one they manage to land on a barge, I wonder if they'll be ready to refuel it and try and fly it home - or whether that idea will be knocked on the head for a while? Costs are probably not dissimilar but the risk of losing it has to be quite significant in the thinking.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 04/08/2016 09:22 pm
If it survives that, I guess Orbcomm will be wanting to use it.
SES.  Orbcomm has no pending launches, AFAIK.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: toruonu on 04/08/2016 09:25 pm
One curiosity. When NASA was showing the replays I noticed one camera showing from over water the pad with a road at the coast. Before launch I think 3-4 minutes to T-0 there were a couple of fire trucks and two cars traveling to the left and then during replays I saw a car driving to the right literally seconds before liftoff.

What road is that and how come it's not closed for traffic during a launch as that looks literally way way too close to the PAD :) And if it's an open road, why isn't it filled with people watching the launch :D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: BioBritt on 04/08/2016 09:27 pm
Now to speculate on the fate of this stage. Dis-assembly? re-use? Testing?

Testing, I imagine, and lots of it. They only have one set of good data points (ORBCOMM-2) for what happens to the rocket during re-entry and successful landing, and I suspect they'll need more before they are just turning these things around like aluminum cans. Lots of little things to learn about what gets burned up or messed up or needs replacing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/08/2016 09:27 pm
So, a mischievous question here: How many successful landings do we need before SpaceX stops calling them 'experimental landings'?  ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/08/2016 09:28 pm
Can't see that happening. They would have to have a full fuel rig (densified!) on the drone ship along with a full launch ground system. too much $$$.

Yes. Would imagine refuelling afloat would be very difficult to achieve.

Perhaps when sea landings were regular and there was a high chance of success, but even so it may not be worth the cost/risk.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 04/08/2016 09:29 pm
So, a mischievous question here: How many successful landings do we need before SpaceX stops calling them 'experimental landings'?  ;)

When they start having experimental reflights
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/08/2016 09:29 pm
So, appropros to recycle, refuel and fly-back to LZ1 after a barge recovery... Who's using Sea Launch's old launch ship now?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: matthewkantar on 04/08/2016 09:33 pm
Stunned. Good thing they put those wings on there.

Enjoy, Matthew.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/08/2016 09:37 pm
What road is that and how come it's not closed for traffic during a launch as that looks literally way way too close to the PAD :) And if it's an open road, why isn't it filled with people watching the launch :D

That could (and would) be literally miles off the pad, the perspective is deceiving with narrow angle camera views from a distance.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Doesitfloat on 04/08/2016 09:38 pm
Way to go Spacex
Falcon FT is 2/3 on landing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Oersted on 04/08/2016 09:38 pm
Not only does SpaceX use densified fuel but they also test the engines before flight and do a hundred other things in preparation for launches. For all those reasons they won't launch from sea in the foreseeable future, if ever.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cebri on 04/08/2016 09:43 pm
Thank you Elon, thank you.

Well, I'm pretty sure he didn't do it on his own...

So: Congratulations to all of the hardworking people at SpaceX.

Of course, but without him this wouldn't have happened. I know there are thousands of engineers that have worked incredibly hard to achieve this goal, but man, this guy, his vision, i can't thank him enough for having disrupted the space industry as much as he has.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/08/2016 09:50 pm
So, appropros to recycle, refuel and fly-back to LZ1 after a barge recovery... Who's using Sea Launch's old launch ship now?

Still tied up somewhere while lawyers argue over who owes what to who until it's finally sold?

Would need a *lot* of work to refit it - losing virtually all the superstructure and creating a big flat deck for a start.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/08/2016 09:54 pm
Still tied up somewhere
Port of Los Angeles / Long Beach, both platform and ship.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/08/2016 09:54 pm
Historic article William, well done! :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 04/08/2016 09:55 pm
So, a mischievous question here: How many successful landings do we need before SpaceX stops calling them 'experimental landings'?  ;)
At least half a dozen successes in a row. Just because they manage to recover a stage, doesn't mean they aren't learning more things that will make the process more reliable.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 04/08/2016 09:59 pm
Now to speculate on the fate of this stage. Dis-assembly? re-use? Testing?

It was amazing and scary to watch.  Hard to believe it stuck.

I'm going out on a limb and predicting this one stays at the Cape and flies again.

I see little that can be learned by shipping it cross country and being torn apart. 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: GregA on 04/08/2016 10:03 pm
What great video coverage spaceX provides eh?

Spectacular landing footage.

And just to ask for even more ... :). I assume that an onboard camera during boost back etc wouldn't work?

We need a drone camera jettisoned during stage separation - it could show the stage 2 head off, then pan to watch the first stage orient and stay wih it till boost back. (Not asking much eh!)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ohsin on 04/08/2016 10:07 pm
Post Launch presser has begun https://www.youtube.com/watch?v=OX9I1KyNa8M

6:12 AM Sunday Tim Peak would be grappling Dragon.

Elon saying almost half of missions have to land at sea.

Hans saying Dragon is in top health GNC door to open in 2hr15min.

Elon saying booster to arrive at  port on Sunday. They'll test engine 10 times in row and then May or June for reflight! Eliminated all prior reasons of failure.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Tuts36 on 04/08/2016 10:13 pm
Elon musk says this booster will be likely to relaunch if test-fires go well at the Cape.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/08/2016 10:14 pm
Ten test fires in a row to re-qualify the booster, and another orbital launch in "June" (!).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: BioBritt on 04/08/2016 10:15 pm
Now to speculate on the fate of this stage. Dis-assembly? re-use? Testing?

It was amazing and scary to watch.  Hard to believe it stuck.

I'm going out on a limb and predicting this one stays at the Cape and flies again.

I see little that can be learned by shipping it cross country and being torn apart.

Wow, Musk just confirmed in the press conference that this one will be brought back to Cape, fired about 10 times, and hopefully re-used! No plans to move it back to Texas!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/08/2016 10:15 pm
I'm sort of losing my mind here. Over on the NASA presser, Elon is calmly talking about re-flying this booster in June! :o
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ohsin on 04/08/2016 10:18 pm
Did he just confirm first recovered booster will simply put on display at Cape?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ehb on 04/08/2016 10:20 pm
Did he just confirm first recovered booster will simply put on display at Cape?

No, at SpX HQ Hawthorne.

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/08/2016 10:20 pm
Just got FAA permission to display December landed 1st stage outside SpaceX in Hawthorne. Need permission as it's so tall and near the airport ... !

I did predict that the first stage to return would be a 'gate guardian' somewhere but I was expecting MacGreggor, not Hawthorne.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ohsin on 04/08/2016 10:25 pm
Max tilt for safe landing 8-9 degrees. It was 2-3 degrees today. Shoes being welded over legs to secure it.

They'll unload it using crane put it on stand and fold legs. Then probably take it to 39A and perform 10 test firings.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 04/08/2016 10:27 pm
Shoes being welded over legs to secure it.

Finally confirms - officially! - what people have been saying since the very first attempt.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ohsin on 04/08/2016 10:34 pm
Next land landings 3 months away(third mission from now). Looking to reduce sea landing to third or fourth, prefer landing on land. 10 or 20 reflight missions per core!? After refurbishment may be even100...

BEAM installing on 15 -16 April. 25-26 May for inflating Beam.

Elon said looking forward to recovering fairing they cost several million.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Machdiamond on 04/08/2016 10:39 pm
Chalk another one for the history books. Awesome!

On another note, I wonder if the final approach was sub-nominal. The first stage approached the barge with a fairly high pitch angle / horizontal speed. Maybe due to winds?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/08/2016 10:44 pm
Chalk another one for the history books. Awesome!

On another note, I wonder if the final approach was sub-nominal. The first stage approached the barge with a fairly high pitch angle / horizontal speed. Maybe due to winds?

Elon said it was due to winds - it was leaning into the wind sort of like an airplane crabbing into the wind to stay on the runway approach in a cross wind.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/08/2016 10:50 pm
Here is the NASA Full-Launch webcast (almost 2 hours long):

https://www.youtube.com/watch?v=rA7h3UBYuvY
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/08/2016 11:07 pm
Here is the NASA Full-Launch webcast (almost 2 hours long):

https://www.youtube.com/watch?v=rA7h3UBYuvY

Cool - And if you look closely at 1:22:30 (and the next 20 seconds), you can actually see a video of the grid fins deploying on the first stage. (top middle, the top left image projected on the launch control wall)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: muazcatalyst on 04/08/2016 11:08 pm
If it survives that, I guess Orbcomm will be wanting to use it.
SES.  Orbcomm has no pending launches, AFAIK.

SES has also stated interests in using a used F9R.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Grandpa to Two on 04/08/2016 11:22 pm
During the launch videos of the second stage engine firing I saw something fluttering on 3 of the camera views. It looked kind of rectangular and two pieces, one atop of the other. The top (outside) piece was vibrating up and down. I've certainly never seen this before, does anyone know what I'm trying to refer too? Only one camera view of the nozzle didn't cover it. Beside this movement was a rod attached to the engine bell.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/08/2016 11:23 pm
Way to go Spacex
Falcon FT is 2/3 on landing.

What do you mean Falcon FT is 2/3 on landing? Heh

OG-2, SES-9, CRS-8.
Those are the FT flights to date.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/08/2016 11:47 pm
Anyone know if the black sheeting on the second stage engine was new?
Purpose?  Doesn't seem to have a reason to change the stage, so maybe something going forward?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/09/2016 12:08 am
Ten test fires in a row to re-qualify the booster, and another orbital launch in "June" (!).
Ha!  That'll drive our cape reporters crazy when we ask them questions on how many puffs they've seen so far.

Shoes being welded over legs to secure it.

Finally confirms - officially! - what people have been saying since the very first attempt.
Rumor of those shoes started 1/2015 when Elon himself said that's what would be done in the reddit AMA.  To my knowledge that is the only source material we had until he again confirmed it today.

Falcon FT is 2/3 on landing.
While true that is the wrong statistic. Falcon FT has achieved 100% landing success, 2/2 for flights where it stood any reasonable chance of success.  SES-9 was an extreme experiment in high energy physics.



Take a look at the landed stage.  The square which is defined by the four feet is nearly parallel and perpendicular to the deck of the ASDS.  Is this intentional or coincedence?  Of course you'd want it to be that way to reduce the chance of setting a foot off the deck (which it would be close to if rotated 45 degrees) but on the other hand forcing it to orient that way would add even more restraint on what the control system was tasked with.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 04/09/2016 12:10 am
Way to go Spacex
Falcon FT is 2/3 on landing.
What do you mean Falcon FT is 2/3 on landing? Heh
OG-2, SES-9, CRS-8.
Those are the FT flights to date.

That's Falcon 9 v1.2 by its licensed designation (http://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/LLS%2014-089%20Rev_1%20ORBCOMM-2%20-%20License%20and%20Orders%20-%20Signed.pdf).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/09/2016 12:19 am
Way to go Spacex
Falcon FT is 2/3 on landing.
What do you mean Falcon FT is 2/3 on landing? Heh
OG-2, SES-9, CRS-8.
Those are the FT flights to date.

That's Falcon 9 v1.2 by its licensed designation (http://www.faa.gov/about/office_org/headquarters_offices/ast/licenses_permits/media/LLS%2014-089%20Rev_1%20ORBCOMM-2%20-%20License%20and%20Orders%20-%20Signed.pdf).

I'm not sure what your trying to say. That we should call it the F9 v1.2? And we are incorrect in calling it a F9 v1.1 FT?

I have not seen Elon or SpaceX call it 1.2 in their publications/social media. So I'm inclined to say that discussions about whether it's name is this or that is a bit pedantic.

Last I heard officially SpaceX just wants us to call whatever the latest version of Falcon is simply the "Falcon 9".

Regardless of name pedantry. We can safely say that of the landing attempts made. The latest version of the "Falcon 9" vehicle has made 3 attempts, 2 of which have succeeded. Can we not?

Thanks, and please do not take offense just trying to interpret your one-liner.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/09/2016 12:29 am
Anyone know if the black sheeting on the second stage engine was new?
Purpose?  Doesn't seem to have a reason to change the stage, so maybe something going forward?


I noticed it on the previous launch as well.  It seemed new to me then.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 12:37 am
Ten test fires in a row to re-qualify the booster, and another orbital launch in "June" (!).
Ha!  That'll drive our cape reporters crazy when we ask them questions on how many puffs they've seen so far.

Shoes being welded over legs to secure it.

Finally confirms - officially! - what people have been saying since the very first attempt.
Rumor of those shoes started 1/2015 when Elon himself said that's what would be done in the reddit AMA.  To my knowledge that is the only source material we had until he again confirmed it today.

Falcon FT is 2/3 on landing.
While true that is the wrong statistic. Falcon FT has achieved 100% landing success, 2/2 for flights where it stood any reasonable chance of success.  SES-9 was an extreme experiment in high energy physics.



Take a look at the landed stage.  The square which is defined by the four feet is nearly parallel and perpendicular to the deck of the ASDS.  Is this intentional or coincedence?  Of course you'd want it to be that way to reduce the chance of setting a foot off the deck (which it would be close to if rotated 45 degrees) but on the other hand forcing it to orient that way would add even more restraint on what the control system was tasked with.

Why one more restraint?  The booster knows the cardinal directions/coordinate system or it would never find the barge and the barge does, too.  Only to us do all faces of a rocket look the same.  Don't think much is left to chance...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/09/2016 12:37 am
What black sheeting? The foil like stuff covering the upper part of the engine? That would probably be thermal insulation and it's been there for a while now.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 12:38 am
Ten test fires in a row to re-qualify the booster, and another orbital launch in "June" (!).
Ha!  That'll drive our cape reporters crazy when we ask them questions on how many puffs they've seen so far.

Shoes being welded over legs to secure it.

Finally confirms - officially! - what people have been saying since the very first attempt.
Rumor of those shoes started 1/2015 when Elon himself said that's what would be done in the reddit AMA.  To my knowledge that is the only source material we had until he again confirmed it today.

Falcon FT is 2/3 on landing.
While true that is the wrong statistic. Falcon FT has achieved 100% landing success, 2/2 for flights where it stood any reasonable chance of success.  SES-9 was an extreme experiment in high energy physics.



Take a look at the landed stage.  The square which is defined by the four feet is nearly parallel and perpendicular to the deck of the ASDS.  Is this intentional or coincedence?  Of course you'd want it to be that way to reduce the chance of setting a foot off the deck (which it would be close to if rotated 45 degrees) but on the other hand forcing it to orient that way would add even more restraint on what the control system was tasked with.

Why one more restraint?  The booster knows the cardinal directions/coordinate system or it would never find the barge and the barge does, too.  Only to us do all faces of a rocket look the same.

I'm sure they control roll, since it reduced the chance of a leg falling off the edge.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JasonAW3 on 04/09/2016 12:41 am
Hey, quick question; does anyone know the schedule of the in-flight abort test?

I'm wondering if that would be the relaunch of stage that just landed?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/09/2016 12:41 am
What black sheeting? The foil like stuff covering the upper part of the engine? That would probably be thermal insulation and it's been there for a while now.
(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=39537.0,3Battach=1108741,3Bimage.pagespeed.ic.LmR6fbZWj0.webp)


I think it's just the black wrap they put on it for transportation. Cut off and leaving the bits covering stage seams?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 04/09/2016 12:42 am
I'm not sure what your trying to say. That we should call it the F9 v1.2? And we are incorrect in calling it a F9 v1.1 FT?

Correct on both counts. Falcon 9 v1.2 is how it is referred to in official filings.  Use it.  Other nomenclature simply confuses matters. (If you think I'm being pedantic, you have not been a party to some earlier long-winded discussions on this site.)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Hungry4info3 on 04/09/2016 12:47 am
Is this the second stage?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/09/2016 12:50 am
Is this the second stage?


Could be a solar panel fairing, but it sure looks like the profile of the second stage.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 12:51 am
What black sheeting? The foil like stuff covering the upper part of the engine? That would probably be thermal insulation and it's been there for a while now.

Thanks, never noticed it before.  Thermal insulation in black is an interesting application... High emissivity (black) is the opposite of a good radiative insulator.  Usually highly reflective like MLI is a vacuum insulator.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: edkyle99 on 04/09/2016 12:52 am
I'm not sure what your trying to say. That we should call it the F9 v1.2? And we are incorrect in calling it a F9 v1.1 FT?

Correct on both counts. Falcon 9 v1.2 is how it is referred to in official filings.  Use it.  Other nomenclature simply confuses matters. (If you think I'm being pedantic, you have not been a party to some earlier long-winded discussions on this site.)
SpaceX personnel have, in presentations at conferences, press and otherwise, called it, repeatedly, "Falcon 9 Upgrade".  Other SpaceX workers have told us on L2 that it is named "Falcon 9 v1.1 Full Thrust".  Now we have "v1.2" on some paperwork but, if memory serves, someone at SpaceX in answer to a question once pointedly said that it was not named "v1.2". 

I have given up trying to figure out the name.  It is the "Falcon 9 with the higher thrust Merlin 1D engines and the stretched second stage and the ulta-cool LOX".

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 12:54 am
I'm not sure what your trying to say. That we should call it the F9 v1.2? And we are incorrect in calling it a F9 v1.1 FT?

Correct on both counts. Falcon 9 v1.2 is how it is referred to in official filings.  Use it.  Other nomenclature simply confuses matters. (If you think I'm being pedantic, you have not been a party to some earlier long-winded discussions on this site.)
SpaceX personnel have, in presentations at conferences, press and otherwise, called it, repeatedly, "Falcon 9 Upgrade".  Other SpaceX workers have told us on L2 that it is named "Falcon 9 v1.1 Full Thrust".  Now we have "v1.2" on some paperwork but, if memory serves, someone at SpaceX in answer to a question once pointedly said that it was not named "v1.2". 

I have given up trying to figure out the name.  It is the "Falcon 9 with the higher thrust Merlin 1D engines and the stretched second stage and the ulta-cool LOX".

 - Ed Kyle

F9 hereafter.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Alastor on 04/09/2016 01:01 am
While true that is the wrong statistic. Falcon FT has achieved 100% landing success, 2/2 for flights where it stood any reasonable chance of success.  SES-9 was an extreme experiment in high energy physics.

I'm pretty sure high energy physics is not the appropriate word for it. The energy of the landing is completely dwarfed by the events in LHC.

Ballistic missile testing, maybe ?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/09/2016 01:02 am
What black sheeting? The foil like stuff covering the upper part of the engine? That would probably be thermal insulation and it's been there for a while now.

Thanks, never noticed it before.  Thermal insulation in black is an interesting application... High emissivity (black) is the opposite of a good radiative insulator.  Usually highly reflective like MLI is a vacuum insulator.

This pic?
(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39537.0;attach=1108988;image)
Looks like a garbage bag to me :P
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 04/09/2016 01:05 am
I have given up trying to figure out the name.  It is the "Falcon 9 with the higher thrust Merlin 1D engines and the stretched second stage and the ulta-cool LOX".
Then use its official name, which by license designation is F9 v1.2.  This is not hard.  the FAA requires that  applicants distinguish their LV's.  SpaceX chose to use F9 v1.2 as a distinguishing identifier in their official filings; what they say in press releases is irrelevant.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jaufgang on 04/09/2016 01:06 am
Did anyone else notice what looks like a crumpled up scrap of paper on the stage 2 engine go flying off into the plume?  It's in the split-screen shot just seconds after stage one landed.  I've attached a video with a close up in slo-mo.

Is it unusual to see something like that?
(edit: fix typo)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/09/2016 01:08 am
What black sheeting? The foil like stuff covering the upper part of the engine? That would probably be thermal insulation and it's been there for a while now.

Thanks, never noticed it before.  Thermal insulation in black is an interesting application... High emissivity (black) is the opposite of a good radiative insulator.  Usually highly reflective like MLI is a vacuum insulator.

It's probably got more to do with keeping off that pesky GOX outgassing from freezing stuff than radiative thermal control. They've been burned frozen with that before.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/09/2016 01:10 am
Did anyone else notice shat looks like a crumpled up scrap of paper on the stage 2 engine go flying off into the plume?  It's in the split-screen shot just seconds after stage one landed.  I've attached a video with a close up in slo-mo.

Is it unusual to see something like that?

No, it literally happens on every launch. There's what I believe as GOX vent somewhere around there and the sudden pressure drop probably causes slow buildup of oxygen ice flakes.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/09/2016 01:14 am
Did anyone else notice shat looks like a crumpled up scrap of paper on the stage 2 engine go flying off into the plume?  It's in the split-screen shot just seconds after stage one landed.  I've attached a video with a close up in slo-mo.

Is it unusual to see something like that?

No, it literally happens on every launch. There's what I believe as GOX vent somewhere around there and the sudden pressure drop probably causes slow buildup of oxygen ice flakes.

Watching from MECO to that ~8m time mark you can clearly see stuff coming out of a small vent tube and forming crystals, then floating a bit around, some goes and flies into the exhaust. That big bit forms, then flattens on that bigger piping above the skirt, then dislodges and flies off into the exhaust around 8m.

Now that you pointed it out I find it entertaining to focus on that bit of piping and see the crystals dance around :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/09/2016 01:18 am
F9 Onboard video of the landing now posted.  Not sure how to post a link more direct than this

https://twitter.com/elonmusk?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jgoldader on 04/09/2016 01:20 am
To any SpaceX folks reading this--I'm a model builder, and I'd sure like to build a whole lot of SpaceX vehicles.  I hope one day we'll have Falcons and Dragons available in plastic or resin at affordable prices.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Paul_G on 04/09/2016 01:25 am
Rockets eye view of the landing

https://twitter.com/SpaceX/status/718605741288894464

Check out the ACS roll control puff at 2 seconds.

There also seems to be a but of a skid after engine shutdown - sporty.

Incredible to compare this view to the almost pixel by pixel recreation of the first landing landing attempt that NSF'ers recreated.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: robertross on 04/09/2016 01:27 am
What a great day for Spaceflight, SpaceX, NASA & the ISS, and even Bigelow.

My congrats to the teams for finally sticking it on that barge. What an accomplishment. I had my doubt they could do, until they made the land landing, and then I started to think they could actually pull it off. Did they ever deliver!

(of course I missed all of it as I was traveling but what a treat to come back home to)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CyndyC on 04/09/2016 01:31 am
So, a mischievous question here: How many successful landings do we need before SpaceX stops calling them 'experimental landings'?  ;)

When they start having experimental reflights

At the press conf Elon implied that would be when landings become boring, non-news items. I forgot the original question there.

Edit: Q was something like how many landings before they consider themselves successful.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Space Ghost 1962 on 04/09/2016 01:44 am
Rockets eye view of the landing

https://twitter.com/SpaceX/status/718605741288894464

Check out the ACS roll control puff at 2 seconds.

There also seems to be a but of a skid after engine shutdown - sporty.

Incredible to compare this view to the almost pixel by pixel recreation of the first landing landing attempt that NSF'ers recreated.

Vehicle appeared to be tilted on touchdown, and righted then cancelled vibration appropriately.

Terminal guidance seems to be improved over prior attempts.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: gongora on 04/09/2016 02:05 am
He said that, but I think he mis-spoke.  I think the order they whispered between them was:

Two ocean landings like today (i.e. CRS-9 and FORMOSAT 5)
Two GEO missions (so, hot ocean landings) (i.e. Thaicom8 and AMOS 6).
CRS mission with land landing (CRS-10).

He began by saying "three months" before the whispering began. That would be CRS-9 or Iridium, wouldn't it?

Next two GTO missions JCSAT and EutelSat/ABS, could be FORMOSAT 5 is the next RTLS?  If CRS-9 is the 3rd flight from now then they're not ramping up the flight rate at all until 3rd quarter and their manifest will be really crammed in the second half of the year.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/09/2016 02:24 am
Seems like you'd want to refly the stage on one of the GTO "hot ocean landing" flights because chances of landing failure are higher, so you're risking a depreciated asset vs a brand new one.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 04/09/2016 02:28 am
Seems like you'd want to refly the stage on one of the GTO "hot ocean landing" flights because chances of landing failure are higher, so you're risking a depreciated asset vs a brand new one.
But there's more performance margin available (by that I mean amount of propellant in the first stage at separation) on the land-return flights, so an early engine-out could be much more easily compensated by using up some of the recovery propellant.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JAFO on 04/09/2016 02:41 am
Working in the Tower at the Sun 'n Fun airshow, we could see the launch but it was during the F-22 Raptor display so we couldn't mention it, the launch was easily visible from Lakeland, FL.

At first I thought it was an inbound aircraft with a VERY bright LED landing light busting the airspace and we were going to have to make the Raptor knock it off, but then it kept climbing, I realized what it was, and I went back to scanning for other traffic.


Congrats, Space X!!!!!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: catdlr on 04/09/2016 02:44 am
CRS-8 | First Stage Landing on Droneship

SpaceX

UNLISTED VIDEO  in 4K



https://www.youtube.com/watch?v=sYmQQn_ZSys
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/09/2016 02:49 am
Seems like you'd want to refly the stage on one of the GTO "hot ocean landing" flights because chances of landing failure are higher, so you're risking a depreciated asset vs a brand new one.
But there's more performance margin available (by that I mean amount of propellant in the first stage at separation) on the land-return flights, so an early engine-out could be much more easily compensated by using up some of the recovery propellant.

True, but probability of failed "hot" landing attempt is likely higher than probability of engine out.

Maybe moot point anyway, since it depends on which customer is ready to step up to the plate.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Seattleite on 04/09/2016 02:51 am
In the airborne video

https://www.youtube.com/watch?v=sYmQQn_ZSys (https://www.youtube.com/watch?v=sYmQQn_ZSys)

I see the right leg deploy after the others - I assumed that all legs deploy at the same time. Is it sequential deployment, or just a sticky leg?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/09/2016 02:58 am
Quote
I see the right leg deploy after the others - I assumed that all legs deploy at the same time. Is it sequential deployment, or just a sticky leg?

The white triangles of clean paint appear simultaneously as the legs unlock at the same time. The right one does seem to take longer to extend, though.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 04/09/2016 02:59 am
I would think they would want all the legs to come out at the same time, for aerodynamic reasons.  But, that said, I think on every flight thus far where we've seen the legs deploy, one has come down a touch later than the others.

As long as the staggered deployment doesn't spin the stage out of control (which it obviously didn't), and as long as they are all down and locked at touchdown, I guess it doesn't really matter.

Oh, and BTW, how great was it that SpaceX decided to share their drone view of the landing (in HD, no less) with us this time?  Maybe it has something to do with the fact that it was a NASA mission being launched, and as such had its feed going out over the satellite system via NASA TV.  Sort of a "now, let's all look nice for the camera" kind of moments... ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: edkyle99 on 04/09/2016 03:03 am
I have given up trying to figure out the name.  It is the "Falcon 9 with the higher thrust Merlin 1D engines and the stretched second stage and the ulta-cool LOX".
Then use its official name, which by license designation is F9 v1.2.  This is not hard.  the FAA requires that  applicants distinguish their LV's.  SpaceX chose to use F9 v1.2 as a distinguishing identifier in their official filings; what they say in press releases is irrelevant.
But that isn't its name.  It is only the name that someone at SpaceX used the day they filled out that particular paperwork.  They probably called it something different the next day.

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/09/2016 03:05 am
Quote
Oh, and BTW, how great was it that SpaceX decided to share their drone view of the landing (in HD, no less) with us this time?  Maybe it has something to do with the fact that it was a NASA mission being launched, and as such had its feed going out over the satellite system via NASA TV.  Sort of a "now, let's all look nice for the camera" kind of moments...

Yes, great live video, and FWIW, it was a NASA chase plane, according to someone else here who knows.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rebel44 on 04/09/2016 03:08 am
above posted video is now available at 4K resolution (and looks great on my 4K monitor).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Bubbinski on 04/09/2016 03:25 am
The Falcon stage stuck the landing in heavy seas, I have to think that is encouraging for future barge landings.  As for doing test firings to re-qualify the flown stage, will they be able to use 39A for these firings, to keep Pad 40 available for regular flows?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/09/2016 03:32 am
The Falcon stage stuck the landing in heavy seas, I have to think that is encouraging for future barge landings.  As for doing test firings to re-qualify the flown stage, will they be able to use 39A for these firings, to keep Pad 40 available for regular flows?

Elon said that they will use 39A to test this recovered stage. It might refly in June.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/09/2016 03:35 am
Did anyone else notice shat looks like a crumpled up scrap of paper on the stage 2 engine go flying off into the plume?  It's in the split-screen shot just seconds after stage one landed.  I've attached a video with a close up in slo-mo.

Is it unusual to see something like that?

No, it literally happens on every launch. There's what I believe as GOX vent somewhere around there and the sudden pressure drop probably causes slow buildup of oxygen ice flakes.

There are similar objects on both sides of the M-Vac.
One comes off around MET:6:40.  Then another one forms in the same place and comes off at MET 9:19.
I see something on the other side at MET 4:20.  It jitters around a bunch but is gone by MET 7:40.
They do look like frost or snow.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mlow on 04/09/2016 03:52 am
Did anyone else notice shat looks like a crumpled up scrap of paper on the stage 2 engine go flying off into the plume?  It's in the split-screen shot just seconds after stage one landed.  I've attached a video with a close up in slo-mo.

Is it unusual to see something like that?

No, it literally happens on every launch. There's what I believe as GOX vent somewhere around there and the sudden pressure drop probably causes slow buildup of oxygen ice flakes.

There are similar objects on both sides of the M-Vac.
One comes off around MET:6:40.  Then another one forms in the same place and comes off at MET 9:19.
I see something on the other side at MET 4:20.  It jitters around a bunch but is gone by MET 7:40.
They do look like frost or snow.

With my limited knowledge I don't think RP-1 would do that, so that leaves LOX. The only other fluid on board. Helium is pressed in gas form in the COPVs, wouldn't crystallize to my knowledge. So it has to be LOX venting, instantly puffing into ice. Clinging to the piping until a gimbal or vibration knocks it off. Probably means nothing. It's also got to be some insanely small amount, like measured in ml's. I think that's a safe bet what do you think?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 04:05 am
In the airborne video

https://www.youtube.com/watch?v=sYmQQn_ZSys (https://www.youtube.com/watch?v=sYmQQn_ZSys)

I see the right leg deploy after the others - I assumed that all legs deploy at the same time. Is it sequential deployment, or just a sticky leg?

I keep seeing the same thing (right leg late), and given how close to touch down everything deploys, it's really scary to watch.

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: TomH on 04/09/2016 04:09 am
Amazing! And this is why FH is late. The importance of this far exceeds FH's maiden flight. Now when FH flies, three stages will be recoverable rather than three thrown away. I think now we will begin to see rapid progress on other fronts: in-flight abort, FH, Dragon V2, Raptor. For awhile I was feeling that progress in space was simply coming to an end. Today, I feel the kind of optimism I felt in 1968.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CyndyC on 04/09/2016 04:10 am
With my limited knowledge I don't think RP-1 would do that, so that leaves LOX. The only other fluid on board. Helium is pressed in gas form in the COPVs, wouldn't crystallize to my knowledge. So it has to be LOX venting, instantly puffing into ice. Clinging to the piping until a gimbal or vibration knocks it off. Probably means nothing. It's also got to be some insanely small amount, like measured in ml's. I think that's a safe bet what do you think?

I'll say none of the above and go outside the box, I mean outside stage 2. It's ultimately melting formerly frozen nitrogen gas from the RCS thrusters at the top of stage 1, when stage 1 was moving max plaid to get out of the way of the stage 2 plume at separation.

Edit: Or maybe hydraulic fluid from the pushers for stage separation.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CyndyC on 04/09/2016 04:18 am
In the airborne video I see the right leg deploy after the others - I assumed that all legs deploy at the same time. Is it sequential deployment, or just a sticky leg?

I keep seeing the same thing (right leg late), and given how close to touch down everything deploys, it's really scary to watch.

Is it not possible the legs can be operated independently just as the grid fans can? The legs are designed to contribute to drag, so even though most talk is about slowing down the stage, you probably don't want to slap on the brakes too hard either.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Brovane on 04/09/2016 04:30 am
I would think they would want all the legs to come out at the same time, for aerodynamic reasons.  But, that said, I think on every flight thus far where we've seen the legs deploy, one has come down a touch later than the others.

As long as the staggered deployment doesn't spin the stage out of control (which it obviously didn't), and as long as they are all down and locked at touchdown, I guess it doesn't really matter.

Oh, and BTW, how great was it that SpaceX decided to share their drone view of the landing (in HD, no less) with us this time?  Maybe it has something to do with the fact that it was a NASA mission being launched, and as such had its feed going out over the satellite system via NASA TV.  Sort of a "now, let's all look nice for the camera" kind of moments... ;)

Maybe now they will share the video from the SES-9 mission.  I always love explosions. 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 04/09/2016 04:32 am
Maybe now they will share the video from the SES-9 mission.  I always love explosions. 

That would be nice. So would OCISLY onboard video from this afternoon.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 04:37 am
With my limited knowledge I don't think RP-1 would do that, so that leaves LOX. The only other fluid on board. Helium is pressed in gas form in the COPVs, wouldn't crystallize to my knowledge. So it has to be LOX venting, instantly puffing into ice. Clinging to the piping until a gimbal or vibration knocks it off. Probably means nothing. It's also got to be some insanely small amount, like measured in ml's. I think that's a safe bet what do you think?

I'll say none of the above and go outside the box, I mean outside stage 2. It's ultimately melting formerly frozen nitrogen gas from the RCS thrusters at the top of stage 1, when stage 1 was moving max plaid to get out of the way of the stage 2 plume at separation.

Edit: Or maybe hydraulic fluid from the pushers for stage separation.
Ideally, yes.

But - the fins are controlled by mechanism that can move them at will - back and forth, and proportionally.  It is part of a servo system.

The legs in comparison are ginormous, and are not so efficient as control surfaces.  They are operated by a one-time push-only system that barely has enough oomph to get them open, going all out.

Being able to control the legs with finesse would take a much heavier actuator.

They were talking about improving the legs, but the end goal, I believe, is just enough power to be able to deploy them earlier during the landing.

My 2c.

Edit: using legs as air brakes was mentioned by Musk a long time ago.  It may no longer be the plan.

One problem: if the legs open before the engine starts, and do so asymetrically, you only have the grid fins to keep the rocket straight, and that's not a lot.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jimbowman on 04/09/2016 04:58 am
The 4k landing footage ain't too bad  ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 05:13 am
Some captures I made soon after launch, but only now have the time to post them.

SpaceX LCC showing grid fin deployed in top left screen.

Series of captures showing the "white stuff" whatever it is. The first three showing it in position and then falling away. The next two showing the stuff reappearing.

View inside the Dragon trunk.

SpaceX LCC showing the Stage 2 LOX tank on the left screen and the first stage on OCISLY on the right screen.

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: daver on 04/09/2016 05:33 am
My son and I watched from A1A.
Truly amazing.
Thank You SpaceX
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:33 am
Some screen capture from the full SpaceX webcast.

Our presenters and control centres.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:34 am
Talking about Dragon.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:37 am
Spacecraft clean room and performing testing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:39 am
Rare view of base of second stage.

Dragon 2.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:42 am
Talking about BEAM.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/09/2016 06:43 am
Is this the second stage?

Yes it is! Cool find; I've never seen a discarded stage from the spacecraft so long after S/C separation before!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:43 am
Dragon late load.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:45 am
Mission profile. They show the second stage splitting in two and Dragon being grabbed by the nose!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:48 am
Some pre launch and launch shots. The nozzle looks like it is back to using the old style thin partial rings to hold the nozzle in place.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 06:49 am
The beautiful landing!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: catdlr on 04/09/2016 07:18 am
Thanks Steven for all the screen recaps, this is needed to document this historic day.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 04/09/2016 08:03 am
Second that. Good job Stephen.

Thanks Steven for all the screen recaps, this is needed to document this historic day.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Humuku on 04/09/2016 08:06 am
There must be footage from a cam on the first stage looking up. In the top left corner the grid fins just deployed. I would love to see the whole footage. Elon to the rescue!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/09/2016 08:21 am
Second that. Good job Stephen.

Thanks Kevin, but my birth certificate says my name is Steven. :-) My Dad named me after Steve Reeves, an actor who starred in many Italian swords and sandals movies. Ironically, Steve Reeves first name was Stephen!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 04/09/2016 08:32 am
Ooops. It's my Irish school upbringing - You'll spell it this way and this way only!

Cheers Steven and thanks for the great updates.

Second that. Good job Stephen.

Thanks Kevin, but my birth certificate says my name is Steven. :-) My Dad named me after Steve Reeves, an actor who starred in many Italian swords and sandals movies. Ironically, Steve Reeves first name was Stephen!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: darkenfast on 04/09/2016 08:38 am
Watching the video looking down as it landed on the barge, the stage appears to have bounced or slid about ten feet from the initial contact.  I think it was headed for pretty close to a bulls-eye when it straightened up, then was blown off center and then kept moving a bit as the thrust died away.  It's a bit like a video shot from the end of a runway showing crosswind landings in a strong breeze.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 04/09/2016 08:51 am
There was quite a breeze out that and it's in the last half second or so that the stage (cutting the power and ...almost hovering) would be very susceptible to the wind.  But you're right - very close to center.

We've also got to remember that the droneship and the stage are both just aiming for a gps lat/long and it takes time to get a gps pos/adjust thrust/get gps pos again/ repeat again for both, so getting them to line up exactly over the same spot at the same second is a tough job.




Watching the video looking down as it landed on the barge, the stage appears to have bounced or slid about ten feet from the initial contact.  I think it was headed for pretty close to a bulls-eye when it straightened up, then was blown off center and then kept moving a bit as the thrust died away.  It's a bit like a video shot from the end of a runway showing crosswind landings in a strong breeze.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MP99 on 04/09/2016 09:19 am
To any SpaceX folks reading this--I'm a model builder, and I'd sure like to build a whole lot of SpaceX vehicles.  I hope one day we'll have Falcons and Dragons available in plastic or resin at affordable prices.
Don't build a lot. Build one and reuse it.

Cheers, Martin
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/09/2016 09:22 am
Second that. Good job Stephen.

Thanks Kevin, but my birth certificate says my name is Steven. :-) My Dad named me after Steve Reeves, an actor who starred in many Italian swords and sandals movies. Ironically, Steve Reeves first name was Stephen!
You're both a couple of "strong men" in my book! ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: StuffOfInterest on 04/09/2016 11:19 am
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/09/2016 11:30 am
The nozzle looks like it is back to using the old style thin partial rings to hold the nozzle in place.

I don't think it was ever any different.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: IRobot on 04/09/2016 11:52 am
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.
A barge like that (heavy, low windage) is not immediately affected by wind and the engine response is also not that fast.
Also wind at high seas is usually laminar, meaning it does not shift so fast.

I think they would benefit more from acceleration sensors on the drone ship to detect wave period and height and constantly upload the info for the first stage, so it can compensate for that.

Alternatively, the whole landing platform could be mobile and tilt + go up and down to compensate for wave movement. Similar principle is used on oil/gas drilling ships, but just for the shaft.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 12:04 pm
I'm sure they are not finished identifying failure modes... ;)
Fix only what is broken.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: StuffOfInterest on 04/09/2016 12:08 pm
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.
A barge like that (heavy, low windage) is not immediately affected by wind and the engine response is also not that fast.
Also wind at high seas is usually laminar, meaning it does not shift so fast.

I didn't mean real time adjustment.  More along the lines of if sustained winds are between 10 and 40 kph 15 minutes before landing time move the barge 3 meters upwind.  Of course, numbers are notional.   Wind gusts and slacking can happen faster than 15 minutes so if the rocket happens to come in during on of those periods then it either ends up a bit downwind or upwind of the center but it still has a  little extra margin to work with.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jabe on 04/09/2016 12:13 pm
curious
to attach the "shoe" to the landing legs.. I wonder if they will use a "stud weld" to weld a bolt to deck to attach the shoe..
curious how the secure it..
jb
https://www.youtube.com/watch?v=Ljz6twH-Pc4
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/09/2016 12:30 pm
In terms of reduced equipment and flexibility, nothing beats Shielded Metal Arc Welding, the common stick welding.
We are talking of steel and SMAW should be the answer.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jabe on 04/09/2016 12:38 pm
In terms of reduced equipment and flexibility, nothing beats Shielded Metal Arc Welding, the common stick welding.
We are talking of steel and SMAW should be the answer.
thought of that but for speed of putting four bolts then bolt on shoe seems faster in rough sees.. then stick weld shoe on as needed.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 04/09/2016 12:48 pm
Yes, but for bolt welding, you would need to have a hole in the deck for each bolt, right?  And you can't pre-position bolt holes because you don't know exactly where the stage will land.

Also, you need to distribute the load the shoes are expected to carry.  Concentrating it in four bolts per shoe sounds like a recipe for some of the welds to break, to be honest.  Wouldn't it be better to spread that load over the perimeter of each shoe with stick welds?

Finally, you can grind off remnants of stick welds, whereas if you drill holes in the deck for bolt welds, eventually you weaken the deck plates, right?  Which would end up requiring deck plate replacement as part of regular ASDS maintenance, not unusual, punched-a-hole-in-it maintenance.

I readily admit I'm not a welder.  But stick welds sound like they would be overall easier and faster than bolt welds, and have greater strength since they distribute the load all along the edges of each shoe.

Edit -- if all you're doing is welding bolts onto the deck without drilling holes, then yeah, no drilling into the deck plates -- but that leaves the issue of concentrating the entire load for each leg through four bolts, each of which has a relatively small welded area.  Still sounds to me like it would be more prone to failure than welding the entire perimeter of each shoe.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jabe on 04/09/2016 12:53 pm
Yes, but for bolt welding, you would need to have a hole in the deck for each bolt, right?  And you can't pre-position bolt holes because you don't know exactly where the stage will land.
watch the vid..REALLY cool tech. nice and simple..
edit:
once again once it is bolted not that much of a rush to weld to add extra support.  While if only stick welding at start you want to get it done fast...
jb
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Chalmer on 04/09/2016 12:58 pm
Quote
I see the right leg deploy after the others - I assumed that all legs deploy at the same time. Is it sequential deployment, or just a sticky leg?

The white triangles of clean paint appear simultaneously as the legs unlock at the same time. The right one does seem to take longer to extend, though.

If you slow the video down it is clear that the three visible leg opens at the same time, but does not extend at the same speed. The left leg is fastest, then the middle leg facing the camera, and the slowest is the right leg.

This i think suggest it is on purpose.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cartman on 04/09/2016 01:03 pm
I don't think it is a coincidence that the slow deploying leg was on the upwind side of the rocket and the fastest one was on the downwind side, while the leg that had the wind on its side was in between. The upwind leg also seemed to move faster after it reached the 90 degree angle.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/09/2016 01:05 pm
Yes, but for bolt welding, you would need to have a hole in the deck for each bolt, right?  And you can't pre-position bolt holes because you don't know exactly where the stage will land.
watch the vid..REALLY cool tech. nice and simple..
edit:
once again once it is bolted not that much of a rush to weld to add extra support.  While if only stick welding at start you want to get it done fast...
jb

In the time I screw two nuts an experienced welder stick welds all four shoes, with some spare time for a coffee.
Switch me with someone faster, its not enough to compete.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/09/2016 01:08 pm
I don't think it is a coincidence that the slow deploying leg was on the upwind side of the rocket and the fastest one was on the downwind side, while the leg that had the wind on its side was in between. The upwind leg also seemed to move faster after it reached the 90 degree angle.
Good catch !
Agree completely.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jabe on 04/09/2016 01:09 pm

In the time I screw two nuts an experienced welder stick welds all four shoes, with some spare time for a coffee.
Switch me with someone faster, its not enough to compete.
I yield to your expertise on this :)  i was amazed how fast it was to put a bolt anywhere you liked..
jb
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/09/2016 01:12 pm
I keep seeing the same thing (right leg late), and given how close to touch down everything deploys, it's really scary to watch.

It's only scary until you realize the deployment takes around 3 seconds for that slow leg, and it starts around 6 seconds before landing. All it needs to do really is deploy and lock-in *before* touchdown. So it really has potentially 2x time at disposal than it actually used. A margin of 2x is probably still better than a whole other number of components and their factors of safety on which the landing critically depends on.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/09/2016 01:17 pm

In the time I screw two nuts an experienced welder stick welds all four shoes, with some spare time for a coffee.
Switch me with someone faster, its not enough to compete.
I yield to your expertise on this :)  i was amazed how fast it was to put a bolt anywhere you liked..
jb

It could be faster than stick welding if you have the studs already fixed to the shoes; otherwise stick welding allows crazy things.
https://www.youtube.com/watch?v=KC_9PETuc08 (https://www.youtube.com/watch?v=KC_9PETuc08)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: litton4 on 04/09/2016 01:36 pm
Anyone else noticed how the stage bounces a couple of times after the initial touchdown, sliding to the left as it does so?

Scary stuff.

Congrats to SpaceX. Made the BBC main news, too.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/09/2016 01:54 pm

In the time I screw two nuts an experienced welder stick welds all four shoes, with some spare time for a coffee.
Switch me with someone faster, its not enough to compete.
I yield to your expertise on this :)  i was amazed how fast it was to put a bolt anywhere you liked..
jb

It could be faster than stick welding if you have the studs already fixed to the shoes; otherwise stick welding allows crazy things.

That's bananas man! 8)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/09/2016 01:57 pm
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.
A barge like that (heavy, low windage) is not immediately affected by wind and the engine response is also not that fast.
Also wind at high seas is usually laminar, meaning it does not shift so fast.

I think they would benefit more from acceleration sensors on the drone ship to detect wave period and height and constantly upload the info for the first stage, so it can compensate for that.

Alternatively, the whole landing platform could be mobile and tilt + go up and down to compensate for wave movement. Similar principle is used on oil/gas drilling ships, but just for the shaft.

Good God man! Don't mention uplinks to the stage from the barge! I did that once, and got very and truly shouted down, by people who 'know' better.

Note, if that landed in 50mph winds, as it appears,  and landed fine, then there doesn't seem much necessity to make any changes whatsoever.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jabe on 04/09/2016 01:58 pm
That's bananas man! 8)
this is why people wear safety shoes.. :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Hauerg on 04/09/2016 02:19 pm
Anyone else noticed how the stage bounces a couple of times after the initial touchdown, sliding to the left as it does so?

Scary stuff.

Congrats to SpaceX. Made the BBC main news, too.

Yeah, what a little wind of 80 kph can do to a tall structure.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 02:46 pm
That's bananas man! 8)
this is why people wear safety shoes.. :)

No, this is why there is Darwinian selection.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ronsmytheiii on 04/09/2016 02:48 pm
https://www.youtube.com/watch?v=sYmQQn_ZSys (https://www.youtube.com/watch?v=sYmQQn_ZSys)

Anyone notice that something fires off after landing near the engines, about 0:17, and 0:26?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kabloona on 04/09/2016 03:03 pm
Quote
Anyone notice that something fires off after landing near the engines, about 0:17, and 0:26?

Looks like maybe some final burps of TEA/TEB venting.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/09/2016 03:03 pm
I'm not getting the credit I deserve for calling this landing more correctly than anyone.  Why has my detailed in depth analysis and prediction not been re-posted in the New York Times?  I called for 1.3 successful landings on this attempt and I was absolutely correct.  Now that it come to pass exactly as I called it revisionist historians are calling it a landing and a bounce rather than the 1.3 landings it obviously was.

http://forum.nasaspaceflight.com/index.php?topic=39862.msg1508512#msg1508512





Anyone notice that something fires off after landing near the engines, about 0:17, and 0:26?

(as George Thorogood said) That don't befront me none.  Much better than the ongoing stream of fire we saw after the Orbcomm-2 landing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 03:51 pm
I'm not getting the credit I deserve for calling this landing more correctly than anyone.  Why has my detailed in depth analysis and prediction not been re-posted in the New York Times?  I called for 1.3 successful landings on this attempt and I was absolutely correct.  Now that it come to pass exactly as I called it revisionist historians are calling it a landing and a bounce rather than the 1.3 landings it obviously was.

http://forum.nasaspaceflight.com/index.php?topic=39862.msg1508512#msg1508512





Anyone notice that something fires off after landing near the engines, about 0:17, and 0:26?

(as George Thorogood said) That don't befront me none.  Much better than the ongoing stream of fire we saw after the Orbcomm-2 landing.
I heard Elon was going to rename the barge after you, but then reconsidered and will actually rename his own self instead.

Or as GT would have said: "I funny too".
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/09/2016 04:13 pm
There must be footage from a cam on the first stage looking up. In the top left corner the grid fins just deployed. I would love to see the whole footage. Elon to the rescue!

I think that is just the normal 1st stage camera that is looking down, mounted high on the interstate.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Stan-1967 on 04/09/2016 04:17 pm
I'm not getting the credit I deserve for calling this landing more correctly than anyone.  Why has my detailed in depth analysis and prediction not been re-posted in the New York Times?  I called for 1.3 successful landings on this attempt and I was absolutely correct.  Now that it come to pass exactly as I called it revisionist historians are calling it a landing and a bounce rather than the 1.3 landings it obviously was.

http://forum.nasaspaceflight.com/index.php?topic=39862.msg1508512#msg1508512


I guess you will have to take solace hanging out with the ghost of Nikola Tesla.   But in all fairness to the NYT,  their layers of fact checkers obviously saw that your "successyness" axis predicting 1.3 landings was based on a linear regression of the previous 3 landings "successyness".   These NYT fact checkers won't be bamboozled by this misuse of statistics.  You can't do a linear regression with just 3 points!  And to top that off, your dependent variable "successyness" needs error bars and you need to show the normality of your data.

geesh
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/09/2016 04:24 pm
That's bananas man! 8)
this is why people wear safety shoes.. :)
I've got some spare sticks out in the garage... Hmmmm... ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/09/2016 04:31 pm
Hmmm, I wonder how Mr. Israel and his colleagues at Arianespace are doing today...? Sorry, couldn't resist considering their declarations of late.

I see Tory sent congratulations. I always liked that about him.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: IRobot on 04/09/2016 04:35 pm
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.
A barge like that (heavy, low windage) is not immediately affected by wind and the engine response is also not that fast.
Also wind at high seas is usually laminar, meaning it does not shift so fast.

I think they would benefit more from acceleration sensors on the drone ship to detect wave period and height and constantly upload the info for the first stage, so it can compensate for that.

Alternatively, the whole landing platform could be mobile and tilt + go up and down to compensate for wave movement. Similar principle is used on oil/gas drilling ships, but just for the shaft.

Good God man! Don't mention uplinks to the stage from the barge! I did that once, and got very and truly shouted down, by people who 'know' better.

Note, if that landed in 50mph winds, as it appears,  and landed fine, then there doesn't seem much necessity to make any changes whatsoever.
Take a closer look, it jumped 3-4x to the side before settling. And the waves were not big. For me the waves are the problem, not the wind.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Scotty on 04/09/2016 04:46 pm
Yikes, did you see the hopping / horizontal skidding, the stage made to the left upon touchdown.
Elon rolled another 7 in his high stakes game of dice.
Still, SpaceX did it first, a totally successful barge landing.
Wonder if they will be able to refly this stage?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: crazy_crank on 04/09/2016 04:56 pm
Yikes, did you see the hopping / horizontal skidding, the stage made to the left upon touchdown.

I could imagine, the first stage is designed to survive little bumps on landing. It's probably impossible to get the hight exactly right in a barge landing, due to waves and stuff? Or am I thinking in the wrong direction?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ChrisGebhardt on 04/09/2016 04:58 pm
Yikes, did you see the hopping / horizontal skidding, the stage made to the left upon touchdown.
Elon rolled another 7 in his high stakes game of dice.
Still, SpaceX did it first, a totally successful barge landing.
Wonder if they will be able to refly this stage?

I'll let someone better informed correct me, but I've heard that if the post-return testing goes well, the stage could be ready to fly again as early as June.  BUT that's highly contingent on the condition of the stage, its hardware, and the amount of work that might be needed to get it ready to fly again.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Orbiter on 04/09/2016 05:07 pm
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.
A barge like that (heavy, low windage) is not immediately affected by wind and the engine response is also not that fast.
Also wind at high seas is usually laminar, meaning it does not shift so fast.

I think they would benefit more from acceleration sensors on the drone ship to detect wave period and height and constantly upload the info for the first stage, so it can compensate for that.

Alternatively, the whole landing platform could be mobile and tilt + go up and down to compensate for wave movement. Similar principle is used on oil/gas drilling ships, but just for the shaft.

Good God man! Don't mention uplinks to the stage from the barge! I did that once, and got very and truly shouted down, by people who 'know' better.

Note, if that landed in 50mph winds, as it appears,  and landed fine, then there doesn't seem much necessity to make any changes whatsoever.

I don't believe it landed in 50mph winds. Those are winds you'd find in an intensifying tropical storm at the surface, not on a relatively clear day. Surface winds were probably like they were at the Cape, 15-20mph. The vehicle probably experienced >50mph winds when it was higher in altitude however, but certainly not as it landed.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/09/2016 05:07 pm
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.

[Jim]
No
[/Jim]

KISS
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: IRobot on 04/09/2016 05:11 pm
I don't believe it landed in 50mph winds. Those are winds you'd find in an intensifying tropical storm at the surface, not on a relatively clear day. Surface winds were probably like they were at the Cape, 15-20mph. The vehicle probably experienced >50mph winds when it was higher in altitude however, but certainly not as it landed.
You could see some foam on wave crests, any sailor will tell you that you need at least +17kn of wind for that to happen (depending on wave height). It is hard to judge from images if the wind speed was higher than that.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Orbiter on 04/09/2016 05:15 pm
I don't believe it landed in 50mph winds. Those are winds you'd find in an intensifying tropical storm at the surface, not on a relatively clear day. Surface winds were probably like they were at the Cape, 15-20mph. The vehicle probably experienced >50mph winds when it was higher in altitude however, but certainly not as it landed.
You could see some foam on wave crests, any sailor will tell you that you need at least +17kn of wind for that to happen (depending on wave height). It is hard to judge from images if the wind speed was higher than that.

That sounds about right, but they certainly weren't approaching 45 knots.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: NovaSilisko on 04/09/2016 05:18 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/09/2016 05:21 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.


It's an ingredient in the world-changing trifecta.  First the land touchdown, then the barge, and third item is the relaunch.  None of them stands alone.  But every step is significant.




And awesome.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/09/2016 05:24 pm
I don't believe it landed in 50mph winds. Those are winds you'd find in an intensifying tropical storm at the surface, not on a relatively clear day. Surface winds were probably like they were at the Cape, 15-20mph. The vehicle probably experienced >50mph winds when it was higher in altitude however, but certainly not as it landed.
You could see some foam on wave crests, any sailor will tell you that you need at least +17kn of wind for that to happen (depending on wave height). It is hard to judge from images if the wind speed was higher than that.

That sounds about right, but they certainly weren't approaching 45 knots.

45knots is just over 50mph.

I agree, that the sea state doesn't seem to be 45knots (> force 8), but it is certainly not insignificant. Looks about F6 to me. The barge is certainly rocking more than I would have expected.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jakusb on 04/09/2016 05:26 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.
Prepare for many more firsts. All realtime streamed.
- Falcon Heavy --> 3! Boosters returning, of which 2 simultaneous.
- Reflight and landing of CRS-8 core
- Launch from 39A
- Inflight abort
- First astronauts by SpaceX
- First dragon2 land landing
- BFR

And likely Elon will think of some more envelopes to push.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 05:27 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.


It's an ingredient in the world-changing trifecta.  First the land touchdown, then the barge, and third item is the relaunch.  None of them stands alone.  But every step is significant.




And awesome.

This event had such a kaboomy lead-in that the suspense had built quite high.
The land landing just happened without any drama.

Agree that this is event two of the trifecta -- and maybe the hardest leg.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: StuffOfInterest on 04/09/2016 05:47 pm
I wonder if on future missions the drone ship will adjust for windage.  Put itself an extra couple of meters downwind to account for any sliding if the wind is over a certain threshold.  If the wind cuts just before landing then they put it down upwind of the circle.  If the wind gusts right at landing they slide a little further downwind but have a bit of extra margin before hitting edge.

[Jim]
No
[/Jim]

KISS

Maybe I'm missing something here, but how is changing the position of the barge by a couple of meters not keeping it simple?  Especially in light of some of the ideas bounced around before.  I was not talking about real time adjustment, just moving a few minutes before landing based on prevailing wind conditions.  The hardware needed is already on board.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/09/2016 05:57 pm
Yikes, did you see the hopping / horizontal skidding, the stage made to the left upon touchdown.
Elon rolled another 7 in his high stakes game of dice.

It may seem like luck to you, but there are real engineering reasons for the robustness of the landing system.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 04/09/2016 06:46 pm
Maybe I'm missing something here, but how is changing the position of the barge by a couple of meters not keeping it simple?  Especially in light of some of the ideas bounced around before.  I was not talking about real time adjustment, just moving a few minutes before landing based on prevailing wind conditions.  The hardware needed is already on board.
In light of the bounce and the 20-30feet of rocket driftage in the wind, biasing the barge position a few feet downwind of the GPS coordinates, with the offset being proportional to the surface wind, doesn't sound like a bad idea at all.

Airliners manage it through sheer tire friction.  Falcon doesn't seem to have grippy toes.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 06:48 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.

Agreed that the land landing was the real "first".

But the sea landing is the "real thing" as far as reusable FHs launching stuff for Mars, and under all of the "mundane" technical achievements lies the fact that these steps are part of that plan.

As a technical feat, it's got a "wow" factor.

But when you consider where it's leading, that when the superlatives start flying.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 06:51 pm
Maybe I'm missing something here, but how is changing the position of the barge by a couple of meters not keeping it simple?  Especially in light of some of the ideas bounced around before.  I was not talking about real time adjustment, just moving a few minutes before landing based on prevailing wind conditions.  The hardware needed is already on board.
In light of the bounce and the 20-30feet of rocket driftage in the wind, biasing the barge position a few feet downwind of the GPS coordinates, with the offset being proportional to the surface wind, doesn't sound like a bad idea at all.

Airliners manage it through sheer tire friction.  Falcon doesn't seem to have grippy toes.

You don't need to shift the barge... This can be (and clearly already is) part of the rocket landing solution.   All they need is to tweak the parameters a bit.

The rocket right now already brings wind into account, shooting upwind (in both position and velocity) so that when all is said and done, after it straightens up for landing, it has zeroed both X and X-dot.   And they almost almost did.   And next time, they probably triple-almost will....

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/09/2016 06:52 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.

Agreed that the land landing was the real "first".

But the sea landing is the "real thing" as far as reusable FHs launching stuff for Mars, and under all of the "mundane" technical achievements lies the fact that these steps are part of that plan.

As a technical feat, it's got a "wow" factor.

But when you consider where it's leading, that when the superlatives start flying.

Remember what Elon kept saying yesterday?  "Full and rapid reuse."  Landing at sea means much slower reuse and probably less "full" as well, compared to landing on land.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mongo62 on 04/09/2016 07:06 pm
In light of the bounce and the 20-30feet of rocket driftage in the wind, biasing the barge position a few feet downwind of the GPS coordinates, with the offset being proportional to the surface wind, doesn't sound like a bad idea at all.

Where are you getting 20-30 feet from? The amount of shift from first contact to final stop looks to be about 10 feet to my eyes.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/09/2016 07:08 pm
Zoom of the 4k landing video:

https://twitter.com/aallan/status/718851627218808832

Is there a way to prevent this kind of bouncing:
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/09/2016 07:12 pm
Zoom of the 4k landing video:

https://twitter.com/aallan/status/718851627218808832 (https://twitter.com/aallan/status/718851627218808832)

From this it appears that the first stage bounces three times and slides about half its diameter, which is 2 meters.
On the scale of the barge this is not significant.
The early statements were that the ASDS could hold its position within 3 meters of the target.  We were told that is was within 1 meter yesterday. 

Uplinks to the rocket and dynamic targeting of the ASDS location would be major complications which have not been shown to be needed.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/09/2016 07:23 pm
Remember what Elon kept saying yesterday?  "Full and rapid reuse."  Landing at sea means much slower reuse and probably less "full" as well, compared to landing on land.
Your thinking does not take into account the progression plan to re-fly them back to land.  Moving the ASDS back and forth between sea, land, and the new landing site at sea would be slow.  Flying them back isn't going to happen soon but they do get to their goals inexorably.

If you want to use yesterday's comments to throw cold water on rapid reusability then the comment to sieze on is that yesterday for the first time I can recall he referred to re-use in about 2 weeks rather than his usual time frame of hours or under 24 hours.

Look for more drone ships as things get rolling faster.  Also, more drone ships means even more capability for FH.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Kaputnik on 04/09/2016 07:24 pm


Uplinks to the rocket and dynamic targeting of the ASDS location would be major complications which have not been shown to be needed.

That is not what was proposed, though. The suggestion was a simple offset, much like the way a shooter dials in a bit of left or rigt to account for the wind. IMHO it could merit consideration IF it is shown that the booster will always slide some distance along the deck after landing in a strong wind.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 07:36 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.

Agreed that the land landing was the real "first".

But the sea landing is the "real thing" as far as reusable FHs launching stuff for Mars, and under all of the "mundane" technical achievements lies the fact that these steps are part of that plan.

As a technical feat, it's got a "wow" factor.

But when you consider where it's leading, that when the superlatives start flying.

Remember what Elon kept saying yesterday?  "Full and rapid reuse."  Landing at sea means much slower reuse and probably less "full" as well, compared to landing on land.

I've been saying from the day the Barge showed up - you have to fly back, or it won't be rapid.

Barging back over the course of a week is just a temporary step.

Elon is on record (once) saying this will be done.

As always, he's behind all the pundits, but eventually gets it right.  [/s]
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rpapo on 04/09/2016 07:37 pm
In light of the bounce and the 20-30feet of rocket driftage in the wind, biasing the barge position a few feet downwind of the GPS coordinates, with the offset being proportional to the surface wind, doesn't sound like a bad idea at all.

Where are you getting 20-30 feet from? The amount of shift from first contact to final stop looks to be about 10 feet to my eyes.
Mark I eyeball, looking at the video and keeping in mind that the barge and the rocket are both much larger than they seem to be.  In other words, my own guestimate.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Coastal Ron on 04/09/2016 07:47 pm
I've been saying from the day the Barge showed up - you have to fly back, or it won't be rapid.

Not necessarily true, especially if you have a "float" or buffer of stages coming back from landings at sea.  The stages that land on land can obviously be turned around the quickest, but if you have 50% of your stages landing at sea they can still make their rapid reuse system work.

Quote
Barging back over the course of a week is just a temporary step.

Operationally having a permanent platform that you don't have to spend money moving back and forth is more ideal than the current barge based system, so barges are likely just an interim solution.  And having a more permanent platform at sea means you are more likely to be able to support refueling and launching while at sea.

Quote
Elon is on record (once) saying this will be done.

As always, he's behind all the pundits, but eventually gets it right.  [/s]

Musk is pretty good about not saying anything until it enters the realm of the possible.  Let's hope his track record is not broken on this subject...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/09/2016 08:19 pm
I've been saying from the day the Barge showed up - you have to fly back, or it won't be rapid.

Not necessarily true, especially if you have a "float" or buffer of stages coming back from landings at sea.  The stages that land on land can obviously be turned around the quickest, but if you have 50% of your stages landing at sea they can still make their rapid reuse system work.

Quote
Barging back over the course of a week is just a temporary step.

Operationally having a permanent platform that you don't have to spend money moving back and forth is more ideal than the current barge based system, so barges are likely just an interim solution.  And having a more permanent platform at sea means you are more likely to be able to support refueling and launching while at sea.

Quote
Elon is on record (once) saying this will be done.

As always, he's behind all the pundits, but eventually gets it right.  [/s]

Musk is pretty good about not saying anything until it enters the realm of the possible.  Let's hope his track record is not broken on this subject...

I think "possible" is clear - we've seen grasshoppers take off. 

A 1000 km hop is sure more than a GH hop, but I think can be done with 3 engines.  It's actually something we can calculate, since most of the flight will be outside the atmosphere and in free fall.   It's like a medium-range ballistic missile, basically.

The question is whether it will be a practical solution, and for that to happen, turn-around must be absolutely trivial.

---

It is true that if you could offload the stage to a transfer boat, horizontally, then that's a valid solution.  You don't get the stage back immediately, but you've pipelined the process.

It will take a crane permanently attached to the barge.  I don't have a problem with that.

In fact, while SpaceX hasn't mentioned it, I'd say it's at least as reasonably good a plan.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/09/2016 08:21 pm
Remember what Elon kept saying yesterday?  "Full and rapid reuse."  Landing at sea means much slower reuse and probably less "full" as well, compared to landing on land.
Your thinking does not take into account the progression plan to re-fly them back to land.

I think that's unlikely to happen, and even if it did, it will still be slower and less "full" since it would consume some life and put the stage at further risk of failure.

Quote
Moving the ASDS back and forth between sea, land, and the new landing site at sea would be slow.  Flying them back isn't going to happen soon but they do get to their goals inexorably.

If you want to use yesterday's comments to throw cold water on rapid reusability then the comment to sieze on is that yesterday for the first time I can recall he referred to re-use in about 2 weeks rather than his usual time frame of hours or under 24 hours.

I never heard him say reuse that fast, just time from HIF to launch.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/09/2016 08:23 pm
Operationally having a permanent platform that you don't have to spend money moving back and forth is more ideal than the current barge based system, so barges are likely just an interim solution.  And having a more permanent platform at sea means you are more likely to be able to support refueling and launching while at sea.

You'd also have only one launch azimuth and flight trajectory.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vapour_nudge on 04/09/2016 08:38 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.

Agreed that the land landing was the real "first".

But the sea landing is the "real thing" as far as reusable FHs launching stuff for Mars, and under all of the "mundane" technical achievements lies the fact that these steps are part of that plan.

As a technical feat, it's got a "wow" factor.

But when you consider where it's leading, that when the superlatives start flying.

Remember what Elon kept saying yesterday?  "Full and rapid reuse."  Landing at sea means much slower reuse and probably less "full" as well, compared to landing on land.

Perhaps he meant full & rapid reuse of the drone ships :-)
Multiple drones seems quite logical. It'd be quite a sight seeing one ASDS heading out to sea while passing another on its way back with precious payload.  "All in a day's work" my old chap
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/09/2016 08:38 pm
Even with as few as three first stage cores at each pad, weekly flights from that pad would be workable (assuming 50% RTLS) with a single ASDS.  Two drone ships makes it easy.  You would have to time the very distant down range flights so that a week return trip was accommodated.  If 4-5 cores per pad are needed or cheaper than another ship, that can be the solution.  All of these adjustments are incremental -- add them as flight rate dictates.  Keeping flexibility on azimuthal and trajectories would seem to be an important feature.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mark K on 04/09/2016 08:41 pm



Remember what Elon kept saying yesterday?  "Full and rapid reuse."  Landing at sea means much slower reuse and probably less "full" as well, compared to landing on land.

I've been saying from the day the Barge showed up - you have to fly back, or it won't be rapid.

Barging back over the course of a week is just a temporary step.

Elon is on record (once) saying this will be done.

As always, he's behind all the pundits, but eventually gets it right.  [/s]

Rapid re-use for Falcon 9 of several months  ould be adequate in any reasonable scenario. Assuming you have several(15 say) different boosters and you are launching every 7(!) days that still is a couple months to process a returning stage.

I can't see Falcon 9 ever being greater than that rate ( or even close to it...) By the time that might be necessary, it would be next generation systems.

As long as you have a pipeline, you don't have to turn around a given stage in a short time, you just have to have a stage ready to go for the next flight.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/09/2016 08:44 pm
It is true that if you could offload the stage to a transfer boat, horizontally, then that's a valid solution.  You don't get the stage back immediately, but you've pipelined the process.

It will take a crane permanently attached to the barge.

Or to the boat, more likely.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Meltro on 04/09/2016 09:02 pm
I've been saying from the day the Barge showed up - you have to fly back, or it won't be rapid.

Barging back over the course of a week is just a temporary step.

Elon is on record (once) saying this will be done.

As always, he's behind all the pundits, but eventually gets it right.  [/s]

What's waiting for you when you fly back? It still needs at least some level of inspection and refurbishment, or at least a new coat of paint. Why not have a floating processing facility? Land, stow, and by the time you're back at the cape you're ready to launch again.

Maybe not all of this could be done, but I'm sure there's plenty that could be accomplished on the way back.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/09/2016 09:06 pm
Question: Given the likely proportion of LEO to GTO & Escape missions, would barge landings be more common than RTLS?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 04/09/2016 09:11 pm
Moved to ASDS fly-back recovery (http://forum.nasaspaceflight.com/index.php?topic=40011.0) thread.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: matthewkantar on 04/09/2016 09:33 pm
The cloud of steam seems to move pretty much perpendicular to the line of sight of the camera. With the stage as a yard stick, I get 23 miles per hour for a wind speed.

Matthew
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: vanoord on 04/09/2016 09:49 pm
Nice ISS pass over the UK just now in fortuitously clear skies - I missed the brighter earlier pass, but still managed to glimpse the tiny Dragon catching up with the ISS. Surprised it's visible to the naked eye given how small it is but caught it just as it was heading into orbital sunset.

Last spacecraft I saw from here was Discovery on STS-131: it's going to take something very special to match it.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 04/09/2016 10:02 pm
Question: Given the likely proportion of LEO to GTO & Escape missions, would barge landings be more common than RTLS?
At the CRS-8 post-launch presser release Elon said they expected near term 50% RTLS and 50% ASDS.  Eventually they expect to achieve between 66% and 75% RTLS.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ames on 04/09/2016 11:00 pm
Caught it here at 20:40 directly overhead in the light evening sky. ISS seemed not as bright as usual (solar panels edge on?). But Dragon clearly visible ~30 seconds behind.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mn on 04/10/2016 01:36 am
Perhaps I missed it but I have not seen any official confirmation of GNC door opening? (not that I suspect it didn't, just wondering why no official confirmation)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Flying Beaver on 04/10/2016 03:35 am
Just watched Dragon chasing down the ISS as they both flew over Victoria BC, Canada. I was able to get some shots through my telescope that were clear enough to make out the bright orange solar arrays of the ISS, but Dragon was sadly just a white blob.

There's another, closer, pass in about 80 minutes so i'll be aiming to get some sharper shots of Dragon.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: schaban on 04/10/2016 03:40 am
Zoom of the 4k landing video:

https://twitter.com/aallan/status/718851627218808832
Looks like ship started tilting before touchdown and that forded stage to skid a bit
Was it due to waves or due to exhaust?
Seems to me due to exhaust because it wasn't dead center this time


Sent from my iPhone using Tapatalk
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mvpel on 04/10/2016 03:40 am

Multiple drones seems quite logical. It'd be quite a sight seeing one ASDS heading out to sea while passing another on its way back with precious payload.  "All in a day's work" my old chap
What will eventually be all in a day's work is refueling the booster at the ASDS and having it fly back to the cape.


Sent from my iPhone using Tapatalk
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 04/10/2016 03:52 am
What would be the deorbit vector for a CRS mission (for Stage 2) 100% retrograde, or downwards or a mix ? I don't have orbital mechanics education. The uneducated instinct would be downwards, but it feels like retrograde burn is the real answer instead.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: edkyle99 on 04/10/2016 04:34 am
What would be the deorbit vector for a CRS mission (for Stage 2) 100% retrograde, or downwards or a mix ? I don't have orbital mechanics education. The uneducated instinct would be downwards, but it feels like retrograde burn is the real answer instead.
I would expect retrograde, primarily. 

 - Ed Kyle
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/10/2016 04:58 am
Zoom of the 4k landing video:

https://twitter.com/aallan/status/718851627218808832 (https://twitter.com/aallan/status/718851627218808832)
Looks like ship started tilting before touchdown and that forded stage to skid a bit
Was it due to waves or due to exhaust?
Seems to me due to exhaust because it wasn't dead center this time

Compared to the thousands of tons of the barges, deck, equipment, and ballast water that comprise the ASDS, the ~50 ton force of the rocket is not significant.  Plus it only acts for a few seconds.
The barge is moved by the waves.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: hans_ober on 04/10/2016 05:27 am
What would be the deorbit vector for a CRS mission (for Stage 2) 100% retrograde, or downwards or a mix ? I don't have orbital mechanics education. The uneducated instinct would be downwards, but it feels like retrograde burn is the real answer instead.

IIRC retrograde. Downwards doesn't help by a lot, it just displaces your orbit by a little bit; you'd need to burn downwards till you're in the atmosphere, as it shifts your perigee to the point where you're burning.

Retrograde is much easier and much more efficient.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jpfulton314 on 04/10/2016 06:00 am
Was it me or was there a slight slide as the stage touched down?  The image seems to show the first stage sliding several feet to the left.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 04/10/2016 06:11 am
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.

Well from the perspective of significantly lowering the costs of launches, achieving successful ASDS landings is, on the whole, probably a bit more important than successful RTLS.  At least in the short term.  This is apparent from an analysis of SpaceX's manifest and Hans' and Elon's comments at their various CRS-8 press conferences.  Downrange landings will make up a larger portion of all recovery attempts, at least in the short term.  It is also needed in making the Falcon Heavy main core recoverable. 

So, assuming that they achieve reuse without much refurbishment needed, downrange landing success is going to play a large limiting factor in how much they can drop the price of launches overall.  Unless they move to a tiered price depending on the likelihood of recovery.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 04/10/2016 06:14 am
Elon saying booster to arrive at  port on Sunday. They'll test engine 10 times in row and then May or June for reflight! Eliminated all prior reasons of failure.

Why do I get the feeling that every time Elon opens his mouth, legions of engineers at SpaceX start swearing?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 04/10/2016 06:25 am
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.

I think the big IF is can SpaceX consistently recover high energy launches with ASDS. This was a softball for ASDS landing. It does help validate a lot of the work, but doesn't give much assurance of the recoverability of a launch when the boostback burn must be eliminated in order to allow for a normal landing burn, say a 5 ton to GTO-1800m/s launch. And we need to see what happens when the waves don't cooperate and ASDS is bobbing and weaving up to the limit.

That being said, I trust SX knows what they're doing. They are willing to fail publicly on non essential goals while learning. They have my utmost respect for that (and eventually succeeding).

What we know for sure is SX will continue to learn and improve its process. If they could somehow get another 2% performance for both stages, and direct extra performance towards recovery burns, it might seal the deal on many of those ASDS landings (Musk kind of said they still have improvements that can be done on the post launch conference, that would be amazing).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jarnis on 04/10/2016 06:30 am
Was it me or was there a slight slide as the stage touched down?  The image seems to show the first stage sliding several feet to the left.

Yep, it "hopped" and slided a bit before becoming to a full stop.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ccicchitelli on 04/10/2016 06:39 am
Here is stabilized and close up 4K video clip of CRS-8 landing on the barge.  Just amazing...

Watching this, istm that the drone ship becomes more stable just as the F9 lands, then resumes rocking and rolling.  Is it possible that plume impingement is actually having a stabilizing effect on the ship?

Or the waves just cooincidentally calmed briefly as it was landing. I think you are underestimating the mass of the barge and the strength of the exhaust plume.

It does make me wonder why SpaceX hasn't installed gyros on the barge to offset roll...

http://www.seakeeper.com/
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/10/2016 06:41 am
What we know for sure is SX will continue to learn and improve its process. If they could somehow get another 2% performance for both stages, and direct extra performance towards recovery burns, it might seal the deal on many of those ASDS landings (Musk kind of said they still have improvements that can be done on the post launch conference, that would be amazing).

I've been thinking about Falcon 9 improvements. These could be

1) Using Syntin (C10H16) fuel. Isp increases by 1.5% and overall propellant density increases by 1.6%, giving an overall impulse density increase of 3.1%. Another fuel is Pinane (C10H18). Isp increases by 1.3% but density increases by 2.2%, giving an impulse density increase of 3.5%.
2) Feeding the turbopump exhaust into the first stage engine bells, like what is done in the second stage.
3) Using carbon fibre propellant tanks.
4) Using staged combustion on the Merlins.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Hauerg on 04/10/2016 07:04 am
Was it me or was there a slight slide as the stage touched down?  The image seems to show the first stage sliding several feet to the left.
There WAS a slide.
Also the last second or so before touchdown the the storm pushed the stage away from the center, the stage was slow enough that the storm had a big effect. And this vector continued after landing when the stage bounced back from the landing compression (?).

<English my native language it is not.>
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 04/10/2016 07:43 am
Here's a different view of the ascent, courtesy of Steve Jurvetson's flickr page (highest resolution I could find).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/10/2016 08:45 am
Zoom of the 4k landing video:

https://twitter.com/aallan/status/718851627218808832

Is there a way to prevent this kind of bouncing:
Yg, I mentioned on the previous barge attempts thread about considering hooks on the tips of the Falcon's landing legs and perpendicular cables strewn across the deck. You would only need to snag one cable with one leg to arrest motion. Of course you would need to sim it to see if other potential oscillations would be introduced that could not be handed by the rocket's gear dampeners. Adding "active dampeners" is possible but creates more complexity and weight.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: toruonu on 04/10/2016 09:07 am
Elon saying booster to arrive at  port on Sunday. They'll test engine 10 times in row and then May or June for reflight! Eliminated all prior reasons of failure.

Why do I get the feeling that every time Elon opens his mouth, legions of engineers at SpaceX start swearing?

Not only SpaceX, Tesla too :) I remember during the D unveiling he even mentioned that it's probably the first time the engineers hear about it too that it'd be nice to have the car plug in after pullimg in the garage ;) few months later we saw the snake alien charging automator video ;)

Also, from my talks with Tesla people who have been with Elon there is always at least one person about who walks around with a notebook making notes of what Elon has promised and when :) somthat they can keep track kf all the unplanned promises :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/10/2016 10:56 am
https://www.youtube.com/watch?v=sYmQQn_ZSys

Points to anyone who can track the poor bird that was blown away by the exhaust.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mongo62 on 04/10/2016 12:45 pm
So, assuming that they achieve reuse without much refurbishment needed, downrange landing success is going to play a large limiting factor in how much they can drop the price of launches overall.  Unless they move to a tiered price depending on the likelihood of recovery.

That is what I expect will be the eventual pricing structure.

RTLS = least expensive
ASDS = somewhat more expensive
Expended = most expensive

SpaceX normally chooses whether the first stage is new or pre-flown. Customer can specify a factory-new stage for a small surcharge (unless it's for a stage to be expended , in which case it's a BIG surcharge)-- eventually would be the other way around, where specifying a flight-proven stage means a surcharge.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/10/2016 03:03 pm
Zoom of the 4k landing video:

https://twitter.com/aallan/status/718851627218808832 (https://twitter.com/aallan/status/718851627218808832)

Is there a way to prevent this kind of bouncing:
Yg, I mentioned on the previous barge attempts thread about considering hooks on the tips of the Falcon's landing legs and perpendicular cables strewn across the deck. You would only need to snag one cable with one leg to arrest motion. Of course you would need to sim it to see if other potential oscillations would be introduced that could not be handed by the rocket's gear dampeners. Adding "active dampeners" is possible but creates more complexity and weight.


Velcro.  Flameproof velcro.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MarsInMyLifetime on 04/10/2016 03:18 pm
Points to anyone who can track the poor bird that was blown away by the exhaust.
Interesting. I see a rather large shadow sweep downward across the left side of the barrier wall at 8, but can't see what is casting the shadow. If that's not the event you mentioned, it is curious in and of itself. (Resolved--I think it is the shadow of one of the legs, not a hapless bird projected by the flame as the light source. So I still do not see your poor bird.)

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Paul_G on 04/10/2016 04:06 pm

Yg, I mentioned on the previous barge attempts thread about considering hooks on the tips of the Falcon's landing legs and perpendicular cables strewn across the deck. You would only need to snag one cable with one leg to arrest motion. Of course you would need to sim it to see if other potential oscillations would be introduced that could not be handed by the rocket's gear dampeners. Adding "active dampeners" is possible but creates more complexity and weight.
[/quote]

But would you need to make sure that you snagged the cable with the rear leg (in direction of skip) - I know the CG of the stage is low, but snagging the forward facing leg in my minds eye could cause the stage to 'trip over'.

Paul
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 04/10/2016 04:14 pm

Yg, I mentioned on the previous barge attempts thread about considering hooks on the tips of the Falcon's landing legs and perpendicular cables strewn across the deck. You would only need to snag one cable with one leg to arrest motion. Of course you would need to sim it to see if other potential oscillations would be introduced that could not be handed by the rocket's gear dampeners. Adding "active dampeners" is possible but creates more complexity and weight.

Quote
But would you need to make sure that you snagged the cable with the rear leg (in direction of skip) - I know the CG of the stage is low, but snagging the forward facing leg in my minds eye could cause the stage to 'trip over'.

Paul

Exactly.  I think it's a good thing that the stage can land and skid a bit.  Anything that would catch a landing foot while there was inertia pushing the landed stage's mass against it greatly increases the chance that either a leg will break, or the stage will tip.

Think of the skid as a final energy dampening maneuver the stage can use to totally arrest its motion relative to its landing pad.

I will also note, for those of you who seem very surprised at the slight bounce, that the Orbcom-2 booster also did a slight bounce on its gear after landing at LZ-1.  Since landing winds were relatively light for that landing, and the final 10 or so meters of descent were done in an absolutely vertical approach, there was no skid.  But if there had been high winds at LZ-1, we could have seen a similar skid.

And finally, ISTR that after the Orbcomm-2 landing, SpaceX tweeted that the slight bounce was not normal or expected, and they needed to refine the engine shutdown procedure to avoid it in the future.  Obviously, we still got the bounce on this second landing, so I'm sure they'll be going back and looking at this once again...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Wolfram66 on 04/10/2016 04:24 pm
You thinking too complex. Just put rare earth magnets in the landing leg pads
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mongo62 on 04/10/2016 04:46 pm
Or maybe do nothing at all. The stage landed just fine, even in fairly heavy seas and a significant wind. I see no need to add weight (which slightly reduces payload) and complexity (which could increase risk) to solve a nonexistent problem.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: wannamoonbase on 04/10/2016 04:52 pm
I feel rather... Jim-y.

I keep hearing so many people talk about how this landing is so historic and world-changing and everything (even the president) and I'm sitting here thinking "but... they already landed back in December, the only difference is they did it at sea this time..." Which is, of course, more difficult, but I wasn't expecting quite as much of a craze as there has been.

That's not to say it's not awesome. Especially because this might be the first stage to re-fly.
Prepare for many more firsts. All realtime streamed.
- Falcon Heavy --> 3! Boosters returning, of which 2 simultaneous.
- Reflight and landing of CRS-8 core
- Launch from 39A
- Inflight abort
- First astronauts by SpaceX
- First dragon2 land landing
- BFR

And likely Elon will think of some more envelopes to push.

1) I'd put a Raptor powered US before any BFR
2) lets all recognize this is the first generation of re-use.  They will learn a lot and then feed that back into design and operations.  Somethings we see and hear now appear clumsy and awkward.

This will improve
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Nomadd on 04/10/2016 04:59 pm
Or maybe do nothing at all. The stage landed just fine, even in fairly heavy seas and a significant wind. I see no need to add weight (which slightly reduces payload) and complexity (which could increase risk) to solve a nonexistent problem.
The skidding wasn't "nonexistent" The stage surviving doesn't mean you ignore potential issues until one of them kills the rocket. Every landing isn't going to be exactly the same and you need as much margin as you can get. The wind could have gusted at the worst possible moment or the boat could have been at a much worse point in it's pitching and rolling. They had some luck with this one they can't count on every time.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: woods170 on 04/10/2016 05:03 pm
Or maybe do nothing at all. The stage landed just fine, even in fairly heavy seas and a significant wind. I see no need to add weight (which slightly reduces payload) and complexity (which could increase risk) to solve a nonexistent problem.
The skidding wasn't "nonexistent" The stage surviving doesn't mean you ignore potential issues until one of them kills the rocket. Every landing isn't going to be exactly the same and you need as much margin as you can get. The wind could have gusted at the worst possible moment or the boat could have been at a much worse point in it's pitching and rolling. They had some luck with this one they can't count on every time.
Yes, and knowing SpaceX they probably already have folks assigned to go investigate and (when deemed necessary) fix this issue.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/10/2016 05:25 pm
Or maybe do nothing at all. The stage landed just fine, even in fairly heavy seas and a significant wind. I see no need to add weight (which slightly reduces payload) and complexity (which could increase risk) to solve a nonexistent problem.
The skidding wasn't "nonexistent" The stage surviving doesn't mean you ignore potential issues until one of them kills the rocket. Every landing isn't going to be exactly the same and you need as much margin as you can get. The wind could have gusted at the worst possible moment or the boat could have been at a much worse point in it's pitching and rolling. They had some luck with this one they can't count on every time.
The wind is exactly why some skidding may actually be DESIRED, not a bug. Immediately stopping the horizontal motion of the leg feet would increase the tip over danger.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Wolfram66 on 04/10/2016 05:31 pm
I wish the zoomed view of the landing above included the top of the stage. This would show how the CGN2 thrusters at the top of the stage were reacting to the wind, landing and subsequent skid on the deck.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ZachS09 on 04/10/2016 05:41 pm
Is this a new tradition: for the spectators behind the MCC in Hawthorne to chant "USA" after a successful first stage landing?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/10/2016 05:51 pm
There's just no give in those legs. Once they lock open, they are rigid with little to no shock absorption to help transfer and dissipate any residual impact energy.

I honestly don't know how much more they can dial this in with all the parameters they need to deal with at the last few seconds. You also get to the point where you simply don't have the mechanical response times to zero out. Especially from other more precarious return profiles.

Maybe having at least a little travel in the legs to absorb some residual velocity/force, whatever, may need to be considered as future upgrade. Which of course I'm sure they have thought about.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/10/2016 05:52 pm

Yg, I mentioned on the previous barge attempts thread about considering hooks on the tips of the Falcon's landing legs and perpendicular cables strewn across the deck. You would only need to snag one cable with one leg to arrest motion. Of course you would need to sim it to see if other potential oscillations would be introduced that could not be handed by the rocket's gear dampeners. Adding "active dampeners" is possible but creates more complexity and weight.

But would you need to make sure that you snagged the cable with the rear leg (in direction of skip) - I know the CG of the stage is low, but snagging the forward facing leg in my minds eye could cause the stage to 'trip over'.

Paul
[/quote]
Paul, I envision the arrestor hooks facing inward toward the engines . The cables are on reels with brakes to slow motion. As I stated, sim it first to see the results and any trades needed if any... Or "get a bigger boat"... ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sghill on 04/10/2016 06:08 pm
There's just no give in those legs. Once they lock open, they are rigid with little to no shock absorption to help transfer and dissipate any residual impact energy.

I honestly don't know how much more they can dial this in with all the parameters they need to deal with at the last few seconds. You also get to the point where you simply don't have the mechanical response times to zero out. Especially from other more precarious return profiles.

Maybe having at least a little travel in the legs to absorb some residual velocity/force, whatever, may need to be considered as future upgrade. Which of course I'm sure they have thought about.

Any attempt to arrest movement at the bottom of the rocket will be difficult because of the small moment arm. Better, IMHO, to have larger lateral thrusters at the top of the booster to arrest movement.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/10/2016 06:19 pm
Interesting but I think a more passive mechanism would be a cleaner solution as opposed to another control system with associated weight and complexity added to the interstage. imo. But, I wonder, now that you brought it up, if such a system could be implemented to the current RCS on the interstage. Not sure it would have the force to zero out as needed though. But interesting none the less.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mfck on 04/10/2016 06:20 pm
Unbelievable. I could understand when the non-successful landings on ASDS have led to mouse trap engineering discussion (heck, I even proposed one... mouse trap), but who would have believed [in the first years of the twenty first century...] that a successful landing leads the same way? The problem is, probably with ASDS not being impressive enough, as in it looks like it needs help and wants advice.

I would n'd the opinion that the skidding is not to be prevented. SX might want to control it better, i.e. being able to control (to some degree and passively) how much it will offset from touchdown to full stop. Things like friction and humidity. The main reason in my view being the suspicion that skidding is probably one of the more balanced and even ways to apply force on the stage, once the engines are off.


:) edited for 21st

PS. If one must propose some kind of improvement, just for the sake of it, one could imagine something like a friction increasing coating on the ASDS deck, that also ablates in the incoming engine plume and becomes less abrasive while heated, thus allowing free skidding close to the point of touchdown and gradually slowing it outwards
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/10/2016 06:28 pm
There's just no give in those legs. Once they lock open, they are rigid with little to no shock absorption to help transfer and dissipate any residual impact energy.

I honestly don't know how much more they can dial this in with all the parameters they need to deal with at the last few seconds. You also get to the point where you simply don't have the mechanical response times to zero out. Especially from other more precarious return profiles.

Maybe having at least a little travel in the legs to absorb some residual velocity/force, whatever, may need to be considered as future upgrade. Which of course I'm sure they have thought about.

Bold mine.
Gif from Ohsin http://forum.nasaspaceflight.com/index.php?topic=33788.msg1470127#msg1470127
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/10/2016 06:35 pm
And take a look here, Orbcomm-2 landing.
http://forum.nasaspaceflight.com/index.php?topic=38149.msg1476033#msg1476033
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/10/2016 06:47 pm
Ok, let's try this. Move your bold over to the "little or no" part and then I'll stipulate that there's a "little" give, thanks for the imagery. And I'll amend by saying, imo, perhaps they should allow more leg travel. Also, IIRC, these are the new leg mechanisms, not the ones flown on Orb. So there is a possibility they tightened things up even further. Not sure.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Wolfram66 on 04/10/2016 06:50 pm
The big question is, WHY is there that horizontal drift at the last 2 meters? Every landing appears to encorporate that sideways drift at touchdown, even the one on land. Is that programmed? I could see if it was to counteract a wind component or wave action, but why on land? Is this ground effect from the engines? RCS doing something at the top of the booster that engines need to compensate for? Just Wagging my tales
{pun intended} 😋
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CJ on 04/10/2016 07:00 pm
Regarding the skid; the F9 was landing in wind, approx 30mph. It's got a big sail area. Of course it's going to have a bit of horizontal motion.

*IF* SpaceX isn't comfortable with the amount of skid placing the F9 too close to the deck edge, wouldn't the easiest, simplest fix be to adjust the ASDS position upwind by a yard or two relative to the aim point for future windy landings? IMHO, that would be a tad easier than trying to reinvent the wheel.

I'm more concerned with the bouncing seen. *IF* that was enough to damage the F9 structurally, or close, it's a problem, and I suspect they might tinker with the engine shutdown timing. If it's not a problem (for example, if the loading experienced is well within limits) I suspect they'll go with the old and wise adage; "if it works, don't try to fix it". 

I'm very much looking forward to seeing what they've done to the F9 post-landing. My wild speculation; one of the purposes of the cherry picker is to put a tarp over the lower part of the rocket, to keep the sea spray off.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/10/2016 07:06 pm
Ok, let's try this. Move your bold over to the "little or no" part and then I'll stipulate that there's a "little" give, thanks for the imagery. And I'll amend by saying, imo, perhaps they should allow more leg travel. Also, IIRC, these are the new leg mechanisms, not the ones flown on Orb. So there is a possibility they tightened things up even further. Not sure.

Sorry if that seemed criticism.
I agree with you that actual legs are too stiff, without real built in damping.
But I remembered well that gif, and some give is clear.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/10/2016 07:13 pm
How "we" see this... ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rcoppola on 04/10/2016 07:13 pm
Ok, let's try this. Move your bold over to the "little or no" part and then I'll stipulate that there's a "little" give, thanks for the imagery. And I'll amend by saying, imo, perhaps they should allow more leg travel. Also, IIRC, these are the new leg mechanisms, not the ones flown on Orb. So there is a possibility they tightened things up even further. Not sure.

Sorry if that seemed criticism.
I agree with you that actual legs are too stiff, without real built in damping.
But I remembered well that gif, and some give is clear.

No, no, absolutely not, none taken. I should have put smiley face or some such thing. Interestingly, I just scaled up that 4K footage %400 and I'm not so sure adding more Give would have mattered here. Although I do believe they need to add more and would have helped, she did come in a little hot and the engine shut-down timing seemed a bit off. With those two variables, plus pitch and roll and wind, she danced around a bit too much..

Also, and I may be alone on this one. I personally think these Drone Ships are too small.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 04/10/2016 07:16 pm
The big question is, WHY is there that horizontal drift at the last 2 meters? Every landing appears to encorporate that sideways drift at touchdown, even the one on land. Is that programmed? I could see if it was to counteract a wind component or wave action, but why on land? Is this ground effect from the engines? RCS doing something at the top of the booster that engines need to compensate for? Just Wagging my tales
{pun intended} 😋
The drift for this particular landing before touch down is because of the wind.  I don't recall much "drift" on OG2 or Jason-3.  The other attempts are not really data points since they were in the middle of large diverts or over control issues.

I think at least half of the sliding is actually related to the bounce in the legs and the strong wind, not just momentum.  But I could be wrong.

My guess is that the next refinement will be in the landing software itself.  In the final moments before touching down the rocket has to "go vertical." Once the rocket is vertical it will drift with the wind, there is no getting around that.  But the "target" for going vertical can be recalculated and the timing of going vertical can probably be refined so the touch down is closer to dead center (or even shifted).  If I'm right about the bounce and if SpaceX can improve the dampening of the legs then I imagine they'll try that too.

As usual, I'm in the "fix learned issues, minor refinement" camp. :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/10/2016 07:22 pm
The stage was crabbing into the wind to keep a line on the landing target.  A second before touchdown, it had to go vertical to achieve a four point landing.  Once crabbing ceased, drift downwind commenced resulting in a short skid.

Easy to fix in software on the stage.  Keep the barge where it is supposed to be.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mme on 04/10/2016 07:26 pm
Ok, let's try this. Move your bold over to the "little or no" part and then I'll stipulate that there's a "little" give, thanks for the imagery. And I'll amend by saying, imo, perhaps they should allow more leg travel. Also, IIRC, these are the new leg mechanisms, not the ones flown on Orb. So there is a possibility they tightened things up even further. Not sure.

Sorry if that seemed criticism.
I agree with you that actual legs are too stiff, without real built in damping.
But I remembered well that gif, and some give is clear.

No, no, absolutely not, none taken. I should have put smiley face or some such thing. Interestingly, I just scaled up that 4K footage %400 and I'm not so sure adding more Give would have mattered here. Although I do believe they need to add more and would have helped, she did come in a little hot and the engine shut-down timing seemed a bit off. With those two variables, plus pitch and roll and wind, she danced around a bit too much..

Also, and I may be alone on this one. I personally think these Drone Ships are too small.
I think that the "give" in those videos could be flex.  If so, it might actually be contributing to "bounce" rather than dampening it.  I don't know what they can do about that that would not add a lot of weight, but I'm also not a real engineer. :)

A bigger barge would be nice, but I think they can still dial it in more before deciding to go that route.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/10/2016 07:30 pm
I still not seeing any reason to change anything. It slid, a couple of meters. So what? The accuracy is good enough and the barge is big enough that its doesn't appear to be a problem. (At least, from the information we have). The conditions were also pretty rough, so this is likely at the extreme end of the range of possible landing scenarios already.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/10/2016 07:33 pm
Just to note the simple "sprung" landing gear on light aircraft are made to flex and give, leading to a bounce upon landing... Personally flight tested by non-destructive means by me thus far... ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cambrianera on 04/10/2016 07:35 pm
I still not seeing any reason to change anything. It slid, a couple of meters. So what? The accuracy is good enough and the barge is big enough that its doesn't appear to be a problem. (At least, from the information we have). The conditions were also pretty rough, so this is likely at the extreme end of the range of possible landing scenarios already.

Also, with more data points, check accurately what's the cause and compensate for it.
Not so difficult to cut the error in half, at least.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/10/2016 07:36 pm
Ok, let's try this. Move your bold over to the "little or no" part and then I'll stipulate that there's a "little" give, thanks for the imagery. And I'll amend by saying, imo, perhaps they should allow more leg travel. Also, IIRC, these are the new leg mechanisms, not the ones flown on Orb. So there is a possibility they tightened things up even further. Not sure.

Sorry if that seemed criticism.
I agree with you that actual legs are too stiff, without real built in damping.
But I remembered well that gif, and some give is clear.

No, no, absolutely not, none taken. I should have put smiley face or some such thing. Interestingly, I just scaled up that 4K footage %400 and I'm not so sure adding more Give would have mattered here. Although I do believe they need to add more and would have helped, she did come in a little hot and the engine shut-down timing seemed a bit off. With those two variables, plus pitch and roll and wind, she danced around a bit too much..

Also, and I may be alone on this one. I personally think these Drone Ships are too small.

I'll add this - there's elastic "give", and there's damping motion.

The first type (those A-struts can compress over their length, for example) is useless and can actually be bad.

The second type requires a damping element, and IIRC they have one such element at the last segment of the telescope.

When we see a few more landings, we'll know if this is even a concern. 
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: envy887 on 04/10/2016 07:39 pm
The smoke cloud covers 3/4 the barge length in 6 seconds, or about 22 knots... Give or take a few.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/10/2016 07:47 pm
The smoke cloud covers 3/4 the barge length in 6 seconds, or about 22 knots... Give or take a few.
Close! :)
http://www.ndbc.noaa.gov/radial_search.php?lat1=28N&lon1=74W&dist=250&ot=A&time=-23
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Wolfram66 on 04/10/2016 08:11 pm
The stage was crabbing into the wind to keep a line on the landing target.  A second before touchdown, it had to go vertical to achieve a four point landing.  Once crabbing ceased, drift downwind commenced resulting in a short skid.

Easy to fix in software on the stage.  Keep the barge where it is supposed to be.

And maybe adding AlNiCo magnets on the landing pads would help? A 2 Kilo magnet on each foot is only about 20 pounds🤓
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/10/2016 09:02 pm
I have a question. Right before capture of Dragon by the Canadarm, the NASA PAO said "the ISS is now in free drift". Isn't the ISS always in free drift?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 04/10/2016 09:10 pm
It was the incorrect call. The Dragon was in free drift.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/10/2016 09:10 pm
I have a question. Right before capture of Dragon by the Canadarm, the NASA PAO said "the ISS is now in free drift". Isn't the ISS always in free drift?

Presumably they meant Dragon.

Anyway, for ISS free drift means that there is no active attitude control - by gyros or thrusters.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Norm38 on 04/10/2016 09:29 pm
On the update thread for berthing, it was said that Dragon was running a bit late due to "drag".
Drag from what?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: yg1968 on 04/10/2016 09:34 pm
On the update thread for berthing, it was said that Dragon was running a bit late due to "drag".
Drag from what?

They explained that it was from atmospheric pressure. There is still some air even that high up (but much less of it obviously).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cmcqueen on 04/11/2016 12:11 am
Watching the final approach of Dragon from 30m to 10m, I couldn't help but opine that it could at least double that snail's pace entry speed, and surely still be able to come in safely. But that's just a gut feel. Why... so... sloooowwww...?

Ideally I'd like to see Dragon do a hoverslam entry to the ISS in future, but that's probably too extreme, nevermind the typical ship entry/landing we're used to in a Star Wars movie. ;)

More seriously, what is the rationale behind such a slow approach? Is it:

* Maximum speed at which Dragon thrusters, sensors and control loop can provide stable and robust control of the approach
* Speed at which an ISS collision would be probably non-catastrophic
* Give ISS astronauts enough reaction time to hit the "abort" button if they see something going wrong
* Other?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/11/2016 12:17 am
* Give ISS astronauts enough reaction time to hit the "abort" button if they see something going wrong
* Other?

Those two, I think.  The "other" is the ability for controllers on the ground to react to failures (in addition to station crew) and so the escape maneuver has less closing velocity to null and reverse.

Aside from safety, a fast-approach is also bad because of the large plume impingement that will result when it has to slow down at the last second.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: FlokiViking on 04/11/2016 12:25 am
* Other?

I suspect it is also because it gives orbital mechanics a chance to do most of the work.  Nothing beats orbital mechanics in terms of predictability and reliability.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 04/11/2016 12:38 am
Watching the final approach of Dragon from 30m to 10m, I couldn't help but opine that it could at least double that snail's pace entry speed, and surely still be able to come in safely. But that's just a gut feel. Why... so... sloooowwww...?

Ideally I'd like to see Dragon do a hoverslam entry to the ISS in future, but that's probably too extreme, nevermind the typical ship entry/landing we're used to in a Star Wars movie. ;)

More seriously, what is the rationale behind such a slow approach? Is it:

* Maximum speed at which Dragon thrusters, sensors and control loop can provide stable and robust control of the approach
* Speed at which an ISS collision would be probably non-catastrophic
* Give ISS astronauts enough reaction time to hit the "abort" button if they see something going wrong
* Other?

Going faster very close to ISS isn't good in my opinion. What I think would help is eliminate all the stop and holds along the way (they would still be defined, but only used if something is wrong). Try to give clearance to the next step a few minutes before it arrives at the upcoming hold point. But I'm sure all of the NASA Space types will call it too risky !
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sewebster on 04/11/2016 12:39 am
On the update thread for berthing, it was said that Dragon was running a bit late due to "drag".
Drag from what?

They explained that it was from atmospheric pressure. There is still some air even that high up (but much less of it obviously).

But... more atmosphere than expected?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jamesh9000 on 04/11/2016 12:48 am
Quote
But... more atmosphere than expected?

Yeah, could be. The top of the atmosphere is not clearly delineated, and can have waves and bumps in it the same as the surface of the ocean. In addition it expands and contracts based on a number of things, temperature solar activity, etc. This can be forecasted but never completely predicted. It's never as clean and neat as the textbooks make it look. Hope this is helpful.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 04/11/2016 01:22 am
Watching the final approach of Dragon from 30m to 10m, I couldn't help but opine that it could at least double that snail's pace entry speed, and surely still be able to come in safely. But that's just a gut feel. Why... so... sloooowwww...?

Ideally I'd like to see Dragon do a hoverslam entry to the ISS in future, but that's probably too extreme, nevermind the typical ship entry/landing we're used to in a Star Wars movie. ;)

More seriously, what is the rationale behind such a slow approach? Is it:

* Maximum speed at which Dragon thrusters, sensors and control loop can provide stable and robust control of the approach
* Speed at which an ISS collision would be probably non-catastrophic
* Give ISS astronauts enough reaction time to hit the "abort" button if they see something going wrong
* Other?
Lessons from MIR tell us otherwise...

https://www.youtube.com/watch?v=tM7fTLLmgbk
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/11/2016 01:23 am
Quote
But... more atmosphere than expected?

Yeah, could be. The top of the atmosphere is not clearly delineated, and can have waves and bumps in it the same as the surface of the ocean. In addition it expands and contracts based on a number of things, temperature solar activity, etc. This can be forecasted but never completely predicted. It's never as clean and neat as the textbooks make it look. Hope this is helpful.

OT ALERT
I was a freshman in college when the first space shuttle went up.  I had a roommate who was an electrical engineering student and we watched it on TV together.  During the launch he became puzzled by a thought and asked me "When it goes out of the top of the atmosphere won't it leave a hole and won't there be a leak?"

Perhaps its that leak from the first shuttle launch that allowed a puff of air to get in Dragon's way.    ::)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: meekGee on 04/11/2016 01:35 am
Quote
But... more atmosphere than expected?

Yeah, could be. The top of the atmosphere is not clearly delineated, and can have waves and bumps in it the same as the surface of the ocean. In addition it expands and contracts based on a number of things, temperature solar activity, etc. This can be forecasted but never completely predicted. It's never as clean and neat as the textbooks make it look. Hope this is helpful.

OT ALERT
I was a freshman in college when the first space shuttle went up.  I had a roommate who was an electrical engineering student and we watched it on TV together.  During the launch he became puzzled by a thought and asked me "When it goes out of the top of the atmosphere won't it leave a hole and won't there be a leak?"

Perhaps its that leak from the first shuttle launch that allowed a puff of air to get in Dragon's way.    ::)

That's a serious problem with your college admissions office...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/11/2016 01:39 am
Watching the final approach of Dragon from 30m to 10m, I couldn't help but opine that it could at least double that snail's pace entry speed, and surely still be able to come in safely. But that's just a gut feel. Why... so... sloooowwww...?

Ideally I'd like to see Dragon do a hoverslam entry to the ISS in future, but that's probably too extreme, nevermind the typical ship entry/landing we're used to in a Star Wars movie. ;)

More seriously, what is the rationale behind such a slow approach? Is it:

* Maximum speed at which Dragon thrusters, sensors and control loop can provide stable and robust control of the approach
* Speed at which an ISS collision would be probably non-catastrophic
* Give ISS astronauts enough reaction time to hit the "abort" button if they see something going wrong
* Other?

"Other" could be "to reduce quantities of nasty thruster residue on the outer surfaces of the ISS to an absolute minimum".. at least that's the excuse used with other visiting vehicles.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/11/2016 01:46 am
OT ALERT
I was a freshman in college when the first space shuttle went up.  I had a roommate who was an electrical engineering student and we watched it on TV together.  During the launch he became puzzled by a thought and asked me "When it goes out of the top of the atmosphere won't it leave a hole and won't there be a leak?"

Perhaps its that leak from the first shuttle launch that allowed a puff of air to get in Dragon's way.    ::)

Mark, just 'coz your roomie was a dud, please don't think all electrical injuneers think like that.. we can't spell either. ::)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Norm38 on 04/11/2016 03:11 am
On the update thread for berthing, it was said that Dragon was running a bit late due to "drag".
Drag from what?

They explained that it was from atmospheric pressure. There is still some air even that high up (but much less of it obviously).

Odd. Yes, the atmosphere is the cause for ISS reboosts, but the ISS is big and that's over a period of months.
I don't recall ever hearing of drag affecting the shuttle, much less something as small as Dragon, hours after launch.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 04/11/2016 03:29 am
I have a question. Right before capture of Dragon by the Canadarm, the NASA PAO said "the ISS is now in free drift". Isn't the ISS always in free drift?

Presumably they meant Dragon.

Anyway, for ISS free drift means that there is no active attitude control - by gyros or thrusters.
Yeah, I've tried docking in KSP with the attitude control on for both vehicles, and it definitely doesn't work. :) You need one to be compliant. Or in real life, you also don't want the control system to go crazy when you start giving it big external moments.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 04/11/2016 03:32 am
The big question is, WHY is there that horizontal drift at the last 2 meters? Every landing appears to encorporate that sideways drift at touchdown, even the one on land. Is that programmed? I could see if it was to counteract a wind component or wave action, but why on land? Is this ground effect from the engines? RCS doing something at the top of the booster that engines need to compensate for? Just Wagging my tales
{pun intended} 😋
The drift for this particular landing before touch down is because of the wind.  I don't recall much "drift" on OG2 or Jason-3.  The other attempts are not really data points since they were in the middle of large diverts or over control issues.

I think at least half of the sliding is actually related to the bounce in the legs and the strong wind, not just momentum.  But I could be wrong.

My guess is that the next refinement will be in the landing software itself.  In the final moments before touching down the rocket has to "go vertical." Once the rocket is vertical it will drift with the wind, there is no getting around that.  But the "target" for going vertical can be recalculated and the timing of going vertical can probably be refined so the touch down is closer to dead center (or even shifted).  If I'm right about the bounce and if SpaceX can improve the dampening of the legs then I imagine they'll try that too.

As usual, I'm in the "fix learned issues, minor refinement" camp. :)

Remember also that as you land, you've basically reduced the effective weight of the stage to near zero, so it doesn't take much to bounce the stage. Also, if you're doing a slight hoverslam, you might actually turn off thrust slightly after you're at your lowest point (since you have to do it either before or after your lowest point). That's what happened for the land landing in December. So the stage may have  slight vertical velocity component when thrust is fully terminated.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: darkenfast on 04/11/2016 05:04 am
Here is stabilized and close up 4K video clip of CRS-8 landing on the barge.  Just amazing...

Watching this, istm that the drone ship becomes more stable just as the F9 lands, then resumes rocking and rolling.  Is it possible that plume impingement is actually having a stabilizing effect on the ship?

Or the waves just cooincidentally calmed briefly as it was landing. I think you are underestimating the mass of the barge and the strength of the exhaust plume.

It does make me wonder why SpaceX hasn't installed gyros on the barge to offset roll...

http://www.seakeeper.com/

Each cubic foot of water that the barge displaces weighs about 64 pounds.  When a wave raises the waterline on one side of the 300-foot barge by a few feet (usually with a lowering of the waterline on the other side, depending on the period of the waves), it brings MILLIONS of pounds of force into play.  The only way ship's stabilizers can work is when the vessel is moving through the water.  Fins sticking out below the waterline are rotated to use the force of the water in the same way that ailerons work on an airplane wing.  The ASDS isn't moving through the water at any appreciable speed so it can't use this trick.  This is the same reason that the weight of an off-center, empty first stage will not have any big effect on the barge's list.  It's simply not heavy enough.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sewebster on 04/11/2016 05:38 am


It does make me wonder why SpaceX hasn't installed gyros on the barge to offset roll...

http://www.seakeeper.com/

Each cubic foot of water that the barge displaces weighs about 64 pounds.  When a wave raises the waterline on one side of the 300-foot barge by a few feet (usually with a lowering of the waterline on the other side, depending on the period of the waves), it brings MILLIONS of pounds of force into play.  The only way ship's stabilizers can work is when the vessel is moving through the water.  Fins sticking out below the waterline are rotated to use the force of the water in the same way that ailerons work on an airplane wing.  The ASDS isn't moving through the water at any appreciable speed so it can't use this trick.  This is the same reason that the weight of an off-center, empty first stage will not have any big effect on the barge's list.  It's simply not heavy enough.

I believe the Seakeeper system is just a gyroscope. They state that nothing protrudes from the hull. Mass typically 2-4% of ship mass. Their list only goes up to 100 t vessels...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dorkmo on 04/11/2016 06:49 am


It does make me wonder why SpaceX hasn't installed gyros on the barge to offset roll...

http://www.seakeeper.com/

Each cubic foot of water that the barge displaces weighs about 64 pounds.  When a wave raises the waterline on one side of the 300-foot barge by a few feet (usually with a lowering of the waterline on the other side, depending on the period of the waves), it brings MILLIONS of pounds of force into play.  The only way ship's stabilizers can work is when the vessel is moving through the water.  Fins sticking out below the waterline are rotated to use the force of the water in the same way that ailerons work on an airplane wing.  The ASDS isn't moving through the water at any appreciable speed so it can't use this trick.  This is the same reason that the weight of an off-center, empty first stage will not have any big effect on the barge's list.  It's simply not heavy enough.

I believe the Seakeeper system is just a gyroscope. They state that nothing protrudes from the hull. Mass typically 2-4% of ship mass. Their list only goes up to 100 t vessels...

"The Seakeeper 35 is designed to achieve 70 to 90% roll reduction on boats up to 140 tons, vessels >100'. Multiple units can be fitted for larger boats. "
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Space Opera on 04/11/2016 07:27 am
I've made a little piece of work, where many things become more obvious:

https://youtu.be/f8ugziyTm20
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/11/2016 07:34 am
I've made a little piece of work, where many things become more obvious:

Is it merely a video artefact... or is the stage actually remaining rock-steady regardless of the movement of the barge??   :o
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: gadgetmind on 04/11/2016 07:44 am
The stage is rock steady with respect to the video stabilisation and absolutely nothing else.

No wonder they want to fit shoes and jack ASAP as those legs are clearly deforming a fair bit as the ship moves around in the water. Some guy ropes would also be a good idea.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Space Opera on 04/11/2016 07:51 am
Is it merely a video artefact... or is the stage actually remaining rock-steady regardless of the movement of the barge??   :o
Hum... well... actually this is the principle of this custom stabilization: make the stage steady whatever its position and orientation.

What we could not here are the deformations of the legs, the delay of some legs in the deployment sequence, the multiple bounces, etc...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: JamesH65 on 04/11/2016 08:19 am
Looks like those legs do a great job absorbing both landing and barge movement;  still not seeing a reason to change anything.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Space Opera on 04/11/2016 11:10 am
Yes, it's the one I've done and already posted 3 messages before yours. :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/11/2016 11:25 am
Yes, it's the one I've done and already posted 3 messages before yours. :)

Oops, lack of coffee on my part. Removed my redundant post.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 04/11/2016 12:04 pm
Do we know the estimated Dragon hatch opening time today?

I've tried to search for this without success.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/11/2016 01:20 pm
those legs are clearly deforming a fair bit as the ship moves around in the water.
I think not.  What you are seeing as barge movement is movement of the barge toward and away from the viewer and the stage is moving along with it in that direction but its not discernable because large motions in that direction are hard to see.  The more telling direction is rocking from right to left.  The stage has been made stable in this direction by video processing and you will see the ASDS does not rock R-L *in this video* because there is (nearly) no  relative movement
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/11/2016 02:50 pm
To any SpaceX folks reading this--I'm a model builder, and I'd sure like to build a whole lot of SpaceX vehicles.  I hope one day we'll have Falcons and Dragons available in plastic or resin at affordable prices.
The spacex store does have f9 models and it previously had a version of f9+Dragon as well.  There's a model building thread on this forum, check there for a lot of model building info.
I've personally built quite a number of spacex models, and am working on a very nice paper model of the F9 in landing configuration from http://axmpaperspacescalemodels.com/ .  If you've got access to a 3d printer (starts at $299 from printrbot) your options increase still further.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Johnnyhinbos on 04/11/2016 03:26 pm
SpaceX's ASDS landing is getting attention from all directions - including from the boating industry. Case in point:

http://www.passagemaker.com/articles/trawler-news/blogs/the-long-way/spacex-rocket-achieves-first-landing-at-sea-video/

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jgoldader on 04/11/2016 03:30 pm

The spacex store does have f9 models and it previously had a version of f9+Dragon as well.  There's a model building thread on this forum, check there for a lot of model building info.
I've personally built quite a number of spacex models, and am working on a very nice paper model of the F9 in landing configuration from http://axmpaperspacescalemodels.com/ .  If you've got access to a 3d printer (starts at $299 from printrbot) your options increase still further.

They have a cardboard flying rocket, but not an accurate scale model. I can't afford the prebuilt ones from Proach, and prebuilts are, well, prebuilt.  I've got a 3D printer on order, but prints from home machines aren't going to be comparable to a resin or injection-molded styrene kit.  I post in the modeling forum here, but the likelihood of a SpaceX person reading this thread is a lot higher than a SpaceX person lurking in the modeling forum, so thought I'd give it a shot!  Ah, 1/144 Falcon 9 (cargo/Dragon/Dragon 2/Heavy), 1/72 Dragon/Dragon 2, 1/24 Dragon/Dragon 2... one can dream, right?  I'd buy them all.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: duh on 04/11/2016 03:51 pm
On the update thread for berthing, it was said that Dragon was running a bit late due to "drag".
Drag from what?

They explained that it was from atmospheric pressure. There is still some air even that high up (but much less of it obviously).

But... more atmosphere than expected?

What am I missing in this point of the discussion?

If there is excessive drag, the orbit height above the earth's surface is going to decrease because the orbital velocity is
decreasing faster than expected. A lower orbit has a shorter orbital period. Therefore in terms of the phasing between the
ISS and the Dragon, the Dragon will be closing (in angular terms) faster than expected. This would necessitate other
rendevous steps happening sooner IF one wishes to keep the same capture time and *assuming* all the remaining burns
are done similar to the preflight plan.

Now if the actual drag on orbit was more than expected, it seems that the first one or two orbit raising manuevers should
be with higher delta V's than the preflight planning. This results in a higher orbit with longer orbital period. Hence the
phase angle between the ISS and the Dragon will close more slowly than the preflight planning had allowed for. If all
the other burns follow close to preflight planning (more or less), the capture can be expected to be late.

Repeating my initial comment: What am I missing? (Please refrain from commenting on things outside the scope of this
thread  :-)  Thanks )
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MarsInMyLifetime on 04/11/2016 05:17 pm
I've made a little piece of work, where many things become more obvious:
One thing that is more obvious in this closeup (thank you for this!) is an event at :21, where a yellow flash goes off at the landing pad closest to us, followed a second later by a smoke puff trailing away from that general location. The flash never reappears in the longer recordings, if it were a navigation beacon. Thoughts on the origin of this flash (and smoke puff, if related)?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/11/2016 05:41 pm
I've made a little piece of work, where many things become more obvious:
One thing that is more obvious in this closeup (thank you for this!) is an event at :21, where a yellow flash goes off at the landing pad closest to us, followed a second later by a smoke puff trailing away from that general location. The flash never reappears in the longer recordings, if it were a navigation beacon. Thoughts on the origin of this flash (and smoke puff, if related)?
Looks like purging propellant residuals to me.

A GOX cloud could ignite short temporary combustion on anything flammable and hot nearby.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 04/11/2016 05:41 pm
I've made a little piece of work, where many things become more obvious:
One thing that is more obvious in this closeup (thank you for this!) is an event at :21, where a yellow flash goes off at the landing pad closest to us, followed a second later by a smoke puff trailing away from that general location. The flash never reappears in the longer recordings, if it were a navigation beacon. Thoughts on the origin of this flash (and smoke puff, if related)?
The flash may not even be at the foot, and any smoke is really hard to see.
It would be interesting to read peoples' conjectures.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/11/2016 05:46 pm
I've made a little piece of work, where many things become more obvious:
One thing that is more obvious in this closeup (thank you for this!) is an event at :21, where a yellow flash goes off at the landing pad closest to us, followed a second later by a smoke puff trailing away from that general location. The flash never reappears in the longer recordings, if it were a navigation beacon. Thoughts on the origin of this flash (and smoke puff, if related)?
The flash may not even be at the foot, and any smoke is really hard to see.
It would be interesting to read peoples' conjectures.

It appears to just be a deck reflection into the landing engine, with a final small "burp" combustion.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Oersted on 04/11/2016 06:00 pm
Thank you Elon, thank you.

Well, I'm pretty sure he didn't do it on his own...

So: Congratulations to all of the hardworking people at SpaceX.

Of course, but without him this wouldn't have happened. I know there are thousands of engineers that have worked incredibly hard to achieve this goal, but man, this guy, his vision, i can't thank him enough for having disrupted the space industry as much as he has.

Exactly.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevin-rf on 04/11/2016 06:07 pm
I just realized, they need to add magnesium strips to the landing legs. That way once landed they could have an instant weld to the deck ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: MarsInMyLifetime on 04/11/2016 08:45 pm
It appears to just be a deck reflection into the landing engine, with a final small "burp" combustion.
The enlarged visual seems to bear out this explanation. And this being the case, the puff of smoke that follows does seem to come from the engine area, almost like an indistinct smoke ring from that burp, and timed about right for being wafted out of the engine and into view.

I still have not spotted ugordan's "poor bird."
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 04/11/2016 09:50 pm
Do we know the estimated Dragon hatch opening time today?

I've tried to search for this without success.


I was looking for this also. I'm assuming that they'll want to get to the late load items pretty quickly.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Space Opera on 04/11/2016 09:56 pm
And here is a slow-motion version (5x slower), which includes temporal optical flow, denoising to remove biggest compression artifacts and slight deconvolution to enhance image quality. But we are still working at resolution limits with heavily compressed video, it won't get better without important efforts:

https://youtu.be/r4G-GY6Sto0
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/11/2016 10:54 pm
And here is a slow-motion version (5x slower), which includes temporal optical flow, denoising to remove biggest compression artifacts and slight deconvolution to enhance image quality. But we are still working at resolution limits with heavily compressed video, it won't get better without important efforts:

https://www.youtube.com/watch?v=r4G-GY6Sto0 (https://www.youtube.com/watch?v=r4G-GY6Sto0)


That's pretty darn good as it is.  It shows that the sideways drift begins just before touchdown, as would be expected with a wind gust, and continues as the booster bounces out of the compression of the legs, probably through residual momentum.  Looks like the legs give it the spring in its step.


Looks good to me.  I wouldn't change a thing, on either the rocket or the video!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 04/11/2016 11:08 pm
Do we know the estimated Dragon hatch opening time today?

I've tried to search for this without success.


I was looking for this also. I'm assuming that they'll want to get to the late load items pretty quickly.

Just caught NASA TV showing some replays of Dragon unloading work in progress; so the answer is, they got in earlier today, some time "this morning". I didn't catch enough to give this as a proper update. My screen cap skills were not working well but here are a couple of unloading shots.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/11/2016 11:18 pm
And here is a slow-motion version (5x slower), which includes temporal optical flow, denoising to remove biggest compression artifacts and slight deconvolution to enhance image quality. But we are still working at resolution limits with heavily compressed video, it won't get better without important efforts:

That's pretty darn good as it is.  It shows that the sideways drift begins just before touchdown, as would be expected with a wind gust, and continues as the booster bounces out of the compression of the legs, probably through residual momentum.  Looks like the legs give it the spring in its step.

Looks good to me.  I wouldn't change a thing, on either the rocket or the video!

Actually, I'd like to make one tiny request if I may:  Could you please move your credits to someplace other than where all the action is?  Maybe top right of screen or vertically up one side??

Thanks!  :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: manoweb on 04/11/2016 11:29 pm
Actually, I'd like to make one tiny request if I may:  Could you please move your credits to someplace other than where all the action is?

I second that request. With all that good work you have made, that big text is really in the way, is it even necessary?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 04/12/2016 12:23 am
With all due respect to everyone asking Space Opera to move his credit, you either don't value his work or misunderstand how fast a credit elsewhere would likely be cropped out and the video spewed all over the 'net by others calming credit.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/12/2016 01:08 am
And here is a slow-motion version
The flame looks much more focused viewed that way.  That should leave a nice mark for ASDS bingo.  Not sure if it'll be visible from photographic distance with the soot that's probably blending everything together but if you could get on deck I'll bet the spot is easy to spot.

There is so much interest and speculation as to when the ASDS will arrive perhaps that would be a good future bingo game.  There seems to be much more variation than positions on the deck and its much more varifyable.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jaufgang on 04/12/2016 02:37 am
On the update thread for berthing, it was said that Dragon was running a bit late due to "drag".
Drag from what?

They explained that it was from atmospheric pressure. There is still some air even that high up (but much less of it obviously).

But... more atmosphere than expected?

What am I missing in this point of the discussion?

If there is excessive drag, the orbit height above the earth's surface is going to decrease because the orbital velocity is
decreasing faster than expected. A lower orbit has a shorter orbital period. Therefore in terms of the phasing between the
ISS and the Dragon, the Dragon will be closing (in angular terms) faster than expected. This would necessitate other
rendevous steps happening sooner IF one wishes to keep the same capture time and *assuming* all the remaining burns
are done similar to the preflight plan.

Now if the actual drag on orbit was more than expected, it seems that the first one or two orbit raising manuevers should
be with higher delta V's than the preflight planning. This results in a higher orbit with longer orbital period. Hence the
phase angle between the ISS and the Dragon will close more slowly than the preflight planning had allowed for. If all
the other burns follow close to preflight planning (more or less), the capture can be expected to be late.

Repeating my initial comment: What am I missing? (Please refrain from commenting on things outside the scope of this
thread  :-)  Thanks )
Perhaps you're missing the drag on the ISS itself, which is orbiting in the same environment as the Dragon and would therefore be experiencing the same orbital dynamic that you described in your first paragraph... perhaps even more so than Dragon due to its large surface area.  Would this not appear to cause ISS to drift away from Dragon?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Pete on 04/12/2016 04:23 am

Perhaps you're missing the drag on the ISS itself, which is orbiting in the same environment as the Dragon and would therefore be experiencing the same orbital dynamic that you described in your first paragraph... perhaps even more so than Dragon due to its large surface area.  Would this not appear to cause ISS to drift away from Dragon?

Yes the ISS is subject to drag, its orbital drag slams the brakes on to the tune of between 1/1000 000 and 1/10 000 000 of a g.

An object with very high density and low surface(effectively zero drag), would take less than an hour to drift a meter ahead of the ISS, from a standing start right next to it.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: manoweb on 04/12/2016 05:41 am
or misunderstand how fast a credit elsewhere would likely be cropped out and the video spewed all over the 'net by others calming credit.

Honestly the credit in that position is the easiest to crop out if one wants to pirate the video.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Ben the Space Brit on 04/12/2016 10:14 am
Just looked at the Dragon unpacking pictures and... wow! Is that mass of white the Dragon's CBM hatch or did they pack that spacecraft like a sardine can this flight?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: woods170 on 04/12/2016 10:46 am
Just looked at the Dragon unpacking pictures and... wow! Is that mass of white the Dragon's CBM hatch or did they pack that spacecraft like a sardine can this flight?
The latter.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 04/12/2016 07:23 pm
From the update thread: http://forum.nasaspaceflight.com/index.php?topic=39537.msg1516807#msg1516807 in the third and final photo, is that a cold-gas settling thruster we see firing there?  Presumably firing to depletion as part of the safeing of the stage?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/12/2016 07:26 pm
From the update thread: http://forum.nasaspaceflight.com/index.php?topic=39537.msg1516807#msg1516807 in the third and final photo, is that a cold-gas settling thruster we see firing there?  Presumably firing to depletion as part of the safeing of the stage?
Cold gas thrusters are at the top of the interstage.  I don't see anything that looks like a thruster firing up there.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: abaddon on 04/12/2016 07:32 pm
From the update thread: http://forum.nasaspaceflight.com/index.php?topic=39537.msg1516807#msg1516807 in the third and final photo, is that a cold-gas settling thruster we see firing there?  Presumably firing to depletion as part of the safeing of the stage?
Cold gas thrusters are at the top of the interstage.  I don't see anything that looks like a thruster firing up there.
I wasn't sure if they were all up there, but if that's the case, then I am seeing something else (or imagining something else).  What I am talking about is what appears to be a downward-facing short white plume at the top of the dark sooty section.  Maybe venting LOX?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 04/12/2016 07:55 pm
From the update thread: http://forum.nasaspaceflight.com/index.php?topic=39537.msg1516807#msg1516807 in the third and final photo, is that a cold-gas settling thruster we see firing there?  Presumably firing to depletion as part of the safeing of the stage?
Cold gas thrusters are at the top of the interstage.  I don't see anything that looks like a thruster firing up there.
I wasn't sure if they were all up there, but if that's the case, then I am seeing something else (or imagining something else).  What I am talking about is what appears to be a downward-facing short white plume at the top of the dark sooty section.  Maybe venting LOX?
I see what you're looking at now.  I think this is the right place for a vent from the kerosene tank.  It would probably be helium venting, then.

The LOX tank is the clean part of the stage.

EDIT: this one has the cold gas thrusters venting: https://cdn3.vox-cdn.com/thumbor/pq0vfKdqz-43WHnlpQjj-RNKV8I=/1020x0/cdn0.vox-cdn.com/uploads/chorus_asset/file/6326477/26300505022_5217a91408_k.0.jpg
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/12/2016 09:02 pm
You can even see the plumes from the downward facing rocket cam at 1:11-1:33.

It's like this was your first rocket launch. Take a look at just about any launch with onboard video, ever.

In short, nothing out of the ordinary. Flames were creeping around the base ever since the first v1.1 launch with good tracking camera views was available - SES-8. With the addition of legs to block some of the air stream, the flames now routinely creep up and lick the base of at least one leg, depending on vehicle orientation and angle of attack.

https://youtu.be/daQRVQ9lEfo?t=15m11s
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: acsawdey on 04/12/2016 09:30 pm
F9's recirculation is nothing at all compared to what Saturn V S1 had:

(http://cdn.ttgtmedia.com/rms/computerweekly/photogalleries/236862/1294_20_the-apollo-11-saturn-v-space-veh~t-apollo-11-pictures-that-amazed-us.jpg)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: The Roadie on 04/12/2016 09:35 pm
Cold gas thrusters are at the top of the interstage.
Actually the bottom - same level as the grid fin actuators, just 45 degrees phased.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 04/12/2016 09:37 pm
F9's recirculation is nothing at all compared to what Saturn V S1 had:
[snip]

Yes, there did seem to be maybe slightly more recirculation than normal - but then again the camera angles and light conditions are not identical between launches.

But here is an even better example of the Saturn V recirculation....  :o It even reached the inter-stage between S1 and S2!  :o :o
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/12/2016 09:41 pm
F9's recirculation is nothing at all compared to what Saturn V S1 had:
[snip]

Yes, there did seem to be maybe slightly more recirculation than normal - but then again the camera angles and light conditions are not identical between launches.

But here is an even better example of the Saturn V recirculation....  :o It even reached the inter-stage between S1 and S2!  :o :o


Heck of a lot of soot to clean off there, too!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 04/13/2016 12:49 am
Remember that was also only the 3rd launch of the F9 FT.  It's possible that in addition to better camera views we're also seeing a new normal of "more flames".  If this is the case, it's likely due to M1D+ upgrades or maybe increased/improved/altered shielding above the engines in order to improve reusability.  With SpaceX calling their TPS shielding "the dance floor", I'm prepared to nickname these recurrent flame worries "Panic! at the Disco".


Panic! at the Disco song with most apropos lyrics: Crazy=Genius


edit: added reference.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Retired Downrange on 04/13/2016 01:13 am
Based on the NASA video of the re-entry burn, I would guess that is when a lot of the soot is deposited on the Falcon 9.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mheney on 04/13/2016 02:42 am
Remember that was also only the 3rd launch of the F9 FT.  It's possible that in addition to better camera views we're also seeing a new normal of "more flames".  If this is the case, it's likely due to M1D+ upgrades or maybe increased/improved/altered shielding above the engines in order to improve reusability.  With SpaceX calling their TPS shielding "the dance floor", I'm prepared to nickname these recurrent flame worries "Panic! at the Disco".

My 15 year old daughter approves of this post.

(And she wonders if the crew Dragon will require Twenty One Pilots ...)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 04/13/2016 03:54 am
Heck of a lot of soot to clean off there, too!

Only if you're silly enough to fly it back home again.  Ain't it far better to just chuck the whole lot in the ocean once you've finished and get the taxpayers to pay for a new one?!?  ;)  ;D
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Norm38 on 04/13/2016 02:34 pm
First stage has arrived at port.

https://www.instagram.com/p/BEFyQh0F8eB
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jarnis on 04/13/2016 04:08 pm
F9's recirculation is nothing at all compared to what Saturn V S1 had:
[snip]

Yes, there did seem to be maybe slightly more recirculation than normal - but then again the camera angles and light conditions are not identical between launches.

But here is an even better example of the Saturn V recirculation....  :o It even reached the inter-stage between S1 and S2!  :o :o


Heck of a lot of soot to clean off there, too!

No worries, it was dunked in the Atlantic to clean it up.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 04/14/2016 07:43 am
First stage has arrived at port.

https://www.instagram.com/p/BEFyQh0F8eB
Direct link to full size image:
https://scontent-sea1-1.cdninstagram.com/t51.2885-15/e35/12917815_847568018702690_455007008_n.jpg
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Endeavour_01 on 04/15/2016 08:22 pm
Was watching the landing with my wife and a friend live. We were yelling and clapping along with the SpaceX people on the webcast. It was one of the most amazing sights I have ever seen. Just wonderful. It was one of those things that I will never forget seeing.

I have been telling my students about SpaceX's plans to land and reuse rockets. Now I get to show them real life video of an RTLS landing and a drone ship landing! :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sanman on 04/16/2016 05:36 am
Was just reading how this CRS-8 flight had the option of landing back on land if they wanted to, but they chose the barge landing to get over that hump:

http://www.universetoday.com/128395/sensational-photos-show-super-smooth-droneship-touchdown-of-spacex-falcon-booster-spacex-vp-interview/

Or have they really gotten past that hump? So it's understood that some flight trajectories make for more difficult landings than others, but does the latest barge landing success mean that barge landings are licked for good, or would another SES-9 type of trajectory likely result in another landing failure? What would they have learned from this landing that would reduce future probability of failure.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: FutureSpaceTourist on 04/16/2016 05:44 am
SpaceX don't yet know for sure what the minimum level of fuel is with which they can still land successfully. As you say there was plenty of margin with CRS-8 and clearly there wasn't enough with SES-9, but where's the boundary point in between?

I'm sure with the data from the two flights SpaceX will have refined their models but there's nothing like an actual landing to verify them.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: gadgetmind on 04/16/2016 08:15 am
but does the latest barge landing success mean that barge landings are licked for good

Sadly that's not how it works. Some failure modes may show up frequently, some very rarely. The JASON3 leg issue could have happened several landings down the line rather than when it did, so who knows what else is lurking?

The only way to increase reliability going forwards is to root cause every failure (instrumentation and where possible examination of wreckage) and even when successful you need to look for anything not 100% nominal (legs not all deploying at same speed, for example) and examine every landed stage to try and spot anything that's not the way it should be.

After all, they probably thought they had the ascent phase licked until CRS-7.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: muazcatalyst on 04/16/2016 12:43 pm
but does the latest barge landing success mean that barge landings are licked for good

Sadly that's not how it works. Some failure modes may show up frequently, some very rarely. The JASON3 leg issue could have happened several landings down the line rather than when it did, so who knows what else is lurking?

The only way to increase reliability going forwards is to root cause every failure (instrumentation and where possible examination of wreckage) and even when successful you need to look for anything not 100% nominal (legs not all deploying at same speed, for example) and examine every landed stage to try and spot anything that's not the way it should be.

After all, they probably thought they had the ascent phase licked until CRS-7.

It's worth mentioning that Jason-3 used F9 v1.1 because the F9 FT had its landing legs upgraded.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cuddihy on 04/16/2016 01:56 pm
I think it's pretty clear that one major root cause of high velocity failures is latency in motor response. The faster your stage is coming down, and the less reserve margin you have for landing, the better and more reliable motor start has to track to commanded start and throttle times and positions. There's going to be a reliability and timing response limit for high likelihood of successful landing, and it's going to track with reserve margin pretty closely.
The question is how far down that curve they can roll. It's all about getting GTO payload over 4-4300 kg and still get the stage to high probability of landing for the reusability cost curve to really start to move.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 04/16/2016 02:24 pm
Was just reading how this CRS-8 flight had the option of landing back on land if they wanted to, but they chose the barge landing to get over that hump:

http://www.universetoday.com/128395/sensational-photos-show-super-smooth-droneship-touchdown-of-spacex-falcon-booster-spacex-vp-interview/

Or have they really gotten past that hump? So it's understood that some flight trajectories make for more difficult landings than others, but does the latest barge landing success mean that barge landings are licked for good, or would another SES-9 type of trajectory likely result in another landing failure? What would they have learned from this landing that would reduce future probability of failure.
Until SpaceX gets 3 in a row ASDS landings we shouldn't be surprised if they loose many more stages. Even land landings aren't assured with a single success.
Landing failure happens... Identify root causes... Address causes... Try again...
That's the game, the fact that SX continues to play this game without repeat problems is a HUGE success in my book.
What we can expect is lower rate of landing failures with more attempts.
They will eventually run out of root causes that need fixing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/16/2016 02:59 pm
Was just reading how this CRS-8 flight had the option of landing back on land if they wanted to, but they chose the barge landing to get over that hump:

http://www.universetoday.com/128395/sensational-photos-show-super-smooth-droneship-touchdown-of-spacex-falcon-booster-spacex-vp-interview/

Or have they really gotten past that hump? So it's understood that some flight trajectories make for more difficult landings than others, but does the latest barge landing success mean that barge landings are licked for good, or would another SES-9 type of trajectory likely result in another landing failure? What would they have learned from this landing that would reduce future probability of failure.
Until SpaceX gets 3 in a row ASDS landings we shouldn't be surprised if they loose many more stages. Even land landings aren't assured with a single success.
Landing failure happens... Identify root causes... Address causes... Try again...
That's the game, the fact that SX continues to play this game without repeat problems is a HUGE success in my book.
What we can expect is lower rate of landing failures with more attempts.
They will eventually run out of root causes that need fixing.

Landing success is the singular roadblock to realizing reuse economics.

At 50% failure rate, you're below 1/3rd of fleet remaining when you've flown all stages a second time.
At 75%, 1/3rd is reached after about 4 reflights.
At 90%, 10 reflights --> this is where it starts to get interesting!!!
(At 99%, 1/3rd of the fleet gets to 'retire' at 100 flights.)

So yes, finding root causes and fixing them will be name of the game for quite a while. 

We can also assume that RTLS will remain much more economical than ASDS landings no matter the success rate.  If RTLS gets beyond 90% early, and drone ship landings are behind that by around 10%, then it will be better to launch a marginal GTO payload on FH (three cores RTLS) instead of stretching an F9 downrange.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lee Jay on 04/16/2016 03:07 pm
Landing success is the singular roadblock to realizing reuse economics.

Singular?  So, reflight failures are no problem?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 04/16/2016 03:10 pm

Landing success is the singular roadblock to realizing reuse economics.


Landing is meaningless if the vehicle can't be reused.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/16/2016 03:15 pm
Landing success is the singular roadblock to realizing reuse economics.

Singular?  So, reflight failures are no problem?

The vehicle is designed for 100 reflights -- or so we've been told.  Even if this 'estimate' is off by a factor of 10, it still pales compared to landing success.  It is a factor, but it also can/will be refined as number of flights/reflights climbs.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: AncientU on 04/16/2016 03:17 pm

Landing success is the singular roadblock to realizing reuse economics.


Landing is meaningless if the vehicle can't be reused.

Agree.

Attempting landing is also meaningless if the vehicle cannot be reused.
Yet they are attempting...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: The Amazing Catstronaut on 04/16/2016 03:18 pm
Both reuse and landing are invaluable of course, but many of the reuse aspects can be tested before you even land the thing for the first time. Landing involves many more uncontrollable variables, whilst economic reuse is mostly just good engineering, inspection and good quality assurance, most of which are intrinsic elements of launching rocket anyway, pre-flown or not.

I'd argue that the only step left for reuse is to fly again.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: nadreck on 04/16/2016 04:28 pm
but does the latest barge landing success mean that barge landings are licked for good

Sadly that's not how it works. Some failure modes may show up frequently, some very rarely. The JASON3 leg issue could have happened several landings down the line rather than when it did, so who knows what else is lurking?

The only way to increase reliability going forwards is to root cause every failure (instrumentation and where possible examination of wreckage) and even when successful you need to look for anything not 100% nominal (legs not all deploying at same speed, for example) and examine every landed stage to try and spot anything that's not the way it should be.

After all, they probably thought they had the ascent phase licked until CRS-7.

Which is why any project, no matter how successful should have the same style of "post-mortem" review looking at all the elements which were not nominal the same way a "post-mortem" on a failed project has.  A negative example of this was at a company I worked at years ago which had a semi-conductor division that had a hybrid analog-digital chip that had be hugely successful and they were licensing it to a Japanese manufacturer. Part of the process involved sending a batch of 100,000 chips manufactured by us to the Japanese company. Shortly after that this company paid for a couple of it execs to come and visit us, they very ceremoniously and respectfully presented the single chip from that batch that failed to our VP of production. We didn't take it seriously and for a couple of years that VP told that story as if the Japanese execs had some quaint but humorous  customs. Eventually, things changed and it was realized what a valuable opportunity had been passed up after the whole company I worked for went through a bottom up quality management process (modelled on Philip Crosby's "Quality is Free") had they investigated why our processes had let that chip pass it might have saved the company a fortune (or not, not every problem is reproducible, but it is worth examining to see what is off off nominal and why). Success isn't good enough, and while perfection may be an unobtainable ideal, you can still always look at what steps are affordable to get closer to it.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: alang on 04/16/2016 05:13 pm
Maybe landings at sea are the best way to test low margin landings rather than risk collateral damage on shore. So perhaps we will see a selection bias that will make barge landings more difficult on top of their inherent difficulty. This could be a good thing for onshore safety and continuous improvement.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 04/16/2016 05:41 pm
There will always be an occasional at-sea failure. They can always push things further and further with hotter and hotter reentry, more slamming of a hoverslam, etc. There's significant performance to be gained by pushing things further. Could get 5-10% performance improvement. That's millions of dollars per mission, if they can get the bugs worked out of it. So I expect that they'll continue to improve things. Maybe try different materials for things, modifications to the grid-fins, early opening of the legs, widening of the legs to use as even larger drag surfaces, thinning of margins, etc. Falcon Heavy center core recovery should push this even further. They could even experiment with adding increasingly sophisticated TPS or hot-structures (titanium vs aluminum) for parts, kind of a prelude to the next steps.

I also wonder if the initial upper stage recovery attempts will be at-sea for the same reasons. That allows more flexibility for orbital alignment. And a more aggressive hover-slamming of the upper stage may be required in order to keep the performance hit of full reuse reasonable.

We're likely to always have some excitement at-sea. :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: macpacheco on 04/16/2016 07:36 pm
I believe people are being overly pessimists about re flights.

Landing is something new. Launching isn't. Relaunching isn't any different from launching, diagnostics can be performed to ensure the recovered stage is ready to relaunch, and if not then do some refurb work.

If Musk says they just need to do 10 static fires to ensure a recovered booster is ready to take willing customer payloads, I'll take his word for it.

Its entirely possible that his 10-20 relaunches won't be possible without some redesign, but hopefully they will find something is wrong before launching. And I fully expect a few relaunches will be possible without any redesign, otherwise they would have had some launch failures due to insufficient structural margins already.

I am however on the camp that the first few re flights should be done without risking expensive customer payloads (Dragon2 in flight abort, first Dragon2 orbital launch, launch a boatload of nanosats, special cheap cargo ISS CRS launches), lower expectations so if there is a launch failure they show they are not risking tens of millions of dollars in destroyed payloads.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 04/16/2016 07:46 pm
Folks, there are plenty of threads and an entire subforum dedicated to SpaceX's reusability efforts - this thread isn't about that.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 04/17/2016 12:22 am
The vehicle is designed for 100 reflights -- or so we've been told.  Even if this 'estimate' is off by a factor of 10, it still pales compared to landing success.  It is a factor, but it also can/will be refined as number of flights/reflights climbs.

Before this "designed for 100 flights" gets picked up by others as the truth and the whole truth and people start believing that's all the info we have let me enter into the record the best information we currently have.  Here is a short transcription from the CRS-8 Q&A, with Elon giving the A:


Quote
I think some aspects of the stage will have no meaningful life.  You can probably do them 1000 missions.  I think almost everything on the stage will be good for 10 or 20 missions.   And with minor refurbishment you can get to 100.

https://www.youtube.com/watch?v=EmN9IJyzBG0          28:20
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: chalz on 04/17/2016 12:37 am
It is 8:30pm, Saturday in Port Canaveral and the webcam is showing the rocket stage still attached to the crane on the dockside stand. Contrary to some expectations SpaceX do not appear to have even visited today despite the weather being dry and calm. The sooty marks on the hull are showing more signs of having been washed by the rain but it still has the striped appearance it did on landing. The webcam has 53 viewers but this morning it was over 100. This is the last sentence of my update.

Edit: I meant this post for the stage live coverage thread but I suppose it works here too. http://forum.nasaspaceflight.com/index.php?topic=40002.0

I will add that BEAM was unloaded from the dragon trunk about 15 hours ago and attached to the ISS without incident, it took about 1 hour. They did it totally remotely from the ground with the astronauts still sleeping which amazed me.
http://forum.nasaspaceflight.com/index.php?topic=40060.0
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mvpel on 04/17/2016 01:54 am
Before this "designed for 100 flights" gets picked up by others as the truth and the whole truth and people start believing that's all the info we have let me enter into the record the best information we currently have.  Here is a short transcription from the CRS-8 Q&A, with Elon giving the A:

I can tell you that Josh Brost, director of civil business development, said these very words in my immediate presence in answer to a question posed to him by Sally Jewell, the US Secretary of the Interior:

"... the design goal is 100 flights ..."

We were standing roughly here: https://goo.gl/maps/dFn2jf9qViM2 - at the south end of the lemonade-and-iced-tea table.

Take it as you will.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: llanitedave on 04/17/2016 04:16 am
Landing success is the singular roadblock to realizing reuse economics.

Singular?  So, reflight failures are no problem?


There hasn't been a reflight failure yet!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CraigLieb on 04/17/2016 04:38 am
Landing success is the singular roadblock to realizing reuse economics.

Singular?  So, reflight failures are no problem?


There hasn't been a reflight failure yet!

I beg to differ. Every orbital rocket flight with payload has failed to refly its first stage.( carefully worded snarky comment)  ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Steven Pietrobon on 04/17/2016 07:56 am
I beg to differ. Every orbital rocket flight with payload has failed to refly its first stage.( carefully worded snarky comment)  ;)

The Space Shuttle reused its boosters, which are considered by some rocket scientists (especially those in Russia), to be the first stage.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ras391 on 04/17/2016 07:32 pm
Anybody know why the video was removed by the user?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: ugordan on 04/17/2016 07:35 pm
Probably because it had the caption stuck on for the entire duration of the video by mistake.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: catdlr on 04/18/2016 12:31 am
Anybody know why the video was removed by the user?

Probably because it had the caption stuck on for the entire duration of the video by mistake.

Updated Video with title removed.  Go back up to view.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Herb Schaltegger on 04/29/2016 11:07 pm
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

https://www.youtube.com/watch?v=KDK5TF2BOhQ

Saw the tweet earlier but just now watched it on my phone. Wow. Look up at the start and watch the descent all the way down - amazing.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rocketguy101 on 04/29/2016 11:16 pm
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle...

https://www.youtube.com/watch?v=KDK5TF2BOhQ

Saw the tweet earlier but just now watched it on my phone. Wow. Look up at the start and watch the descent all the way down - amazing.

love the sound too!!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cartman on 04/29/2016 11:21 pm
The 360 degree video that SpaceX just posted has many useful clues. I counted 17 seconds from the arrival of the sonic boom to the stage landing. The engine was running from the beginning of the video,  so the landing burn was at least 24 seconds long.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: starsilk on 04/29/2016 11:33 pm
for the droneship nerds, turn around completely, you can get a pretty good look at some of the hardware mounted near the camera...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Comga on 05/01/2016 02:28 am
Wow - SpaceX just tweeted a 360 degree video of the stage landing on OCISLY. You have to view it on YouTube, but if viewed with smartphone you can move your phone around to adjust viewing angle..

Saw the tweet earlier but just now watched it on my phone. Wow. Look up at the start and watch the descent all the way down - amazing.

love the sound too!!

Is that the (double?) sonic boom around seven seconds in?

We can see the Merlin's fiery"dragon burp" about four seconds after engine shut-down.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 05/01/2016 03:06 am
When's Dragon coming back?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mkent on 05/01/2016 04:21 am
When's Dragon coming back?

May 11th
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/06/2016 02:42 pm
Would there be any value in have JRtI out near the CRS-8 Dragon splashdown as a working platform? Perhaps for fast-recovery helicopter staging?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 05/06/2016 03:41 pm
Would there be any value in have JRtI out near the CRS-8 Dragon splashdown as a working platform? Perhaps for fast-recovery helicopter staging?
It would be like dragging a ball and chain around your ankle while collecting the results of a javelin meet.

There are much faster ships available for rent with helicopter pads, if that's what you wanted to do.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/06/2016 04:43 pm
Would there be any value in have JRtI out near the CRS-8 Dragon splashdown as a working platform? Perhaps for fast-recovery helicopter staging?
It would be like dragging a ball and chain around your ankle while collecting the results of a javelin meet.

There are much faster ships available for rent with helicopter pads, if that's what you wanted to do.
I'm not sure how the speed of the helipad ship is relevant, to be honest. The point of my suggestion would be to have somewhere close by for a helicopter to come and pick up a few items. I don't even know if access to the Dragon content is feasible at sea; JRtI might or might not be an opportunity to make suitable conditions for Dragon access. Certainly so far everyone has been willing to wait for Dragon to come to port, but there might still be value in faster access to some items (even though that might delay delivery of the rest of the cargo)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 05/06/2016 05:45 pm
Take a look at the existing recovery ship.  It has a fantail, that's all you need.

ASDS requires a minder tug to tow it (slowly) into position.  That's two slow ships doing what one fast ship, or one ship with a helipad, could do... *if* that's what you wanted to do in the first place.

IIRC SpaceX has been using a fast boat to get early cargo back, some the dragon capsule takes a more leisurely return on the recovery ship.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/06/2016 08:26 pm
Take a look at the existing recovery ship.  It has a fantail, that's all you need.

ASDS requires a minder tug to tow it (slowly) into position.  That's two slow ships doing what one fast ship, or one ship with a helipad, could do... *if* that's what you wanted to do in the first place.

IIRC SpaceX has been using a fast boat to get early cargo back, some the dragon capsule takes a more leisurely return on the recovery ship.
The fast boat is news to me... if I can trust your recollection :) . I thought SpaceX didn't open Dragon until they got it to port. If they've already opened it at sea, then I agree that having an ASDS there serves little purpose, other than potentially improving transit time slightly. The benefit of ASDS, of course, is that it's already on the SpaceX books.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 05/06/2016 10:13 pm
From Wikipedia's article on CRS-1:
Quote
SpaceX technicians will open the side hatch of the vehicle and retrieve these time-critical items. The critical cargo items will be placed on a fast-boat for the 450-Kilometer trip back to California for eventual return to NASA that will then take care of the precious science cargo and handle post-flight analysis of the samples.[17] The rest of the cargo will be unloaded once the Dragon capsule reaches SpaceX's test facility in McGregor, Texas.
I don't think they necessarily do this for every recovery.  The time I remember it being talked about there was some special CRS-contract bonus at stake if the cargo could be returned in N hours.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Zed_Noir on 05/07/2016 01:42 am
Would there be any value in have JRtI out near the CRS-8 Dragon splashdown as a working platform? Perhaps for fast-recovery helicopter staging?

Helos is not suitable for retrieve flights from the splashdown site. Which is beyond the normal operating range of most maritime helos that requires a landing platform bigger than the current SpaceX support ships have.

Of course if you can get an Osprey Vertol for a few hours. It might be possible. Probably not desirable.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: gospacex on 05/07/2016 12:43 pm
the title still has "NET April" :D   I'm pretty sure it won't slip, as it already happened
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OnWithTheShow on 05/07/2016 01:56 pm
Havent they, or if not could they, shift(ed) the landing zone closer to coast as their accuracy improves?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 05/07/2016 02:55 pm
Havent they, or if not could they, shift(ed) the landing zone closer to coast as their accuracy improves?
Perhaps.  But I bet the safety distance is a function of "if everything possible goes wrong" analysis (make sure there's no way it falls on someone's head), and that sort of thing isn't going to be affected by better understanding of how things work when everything goes right.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mulp on 05/10/2016 07:43 am
When's Dragon coming back?
Tomorrow, Wednesday, May 11 if the weather is good, May 14 backup date.  nasa tv 9 am edt start, for departure. Hits pacific 3pm no live coverage
http://www.nasa.gov/press-release/nasa-tv-to-broadcast-dragon-departure-from-international-space-station
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: rubtest on 05/10/2016 11:28 am
Sorry for the dumb question , but why dont SpaceX uses heavy Helicopter to retrieve the dragon ?
Is it a financial problem ??
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: su27k on 05/10/2016 11:34 am
In thread http://forum.nasaspaceflight.com/index.php?topic=37846.msg1530418#msg1530418, it is mentioned this Dragon's TPS has intentionally made defects (sounds dangerous to me, but I guess they know what they're doing...) and robotic arm is used to try to find them as an exercise for future commercial crew missions. This is the first time I heard of this, has this been mentioned elsewhere? How do they do the examination when most of the TPS is covered by the trunk?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 05/10/2016 11:41 am
Sorry for the dumb question , but why dont SpaceX uses heavy Helicopter to retrieve the dragon ?
Is it a financial problem ??

There is no helicopter with the capability (lift and range)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Silmfeanor on 05/10/2016 10:21 pm
In thread http://forum.nasaspaceflight.com/index.php?topic=37846.msg1530418#msg1530418, it is mentioned this Dragon's TPS has intentionally made defects (sounds dangerous to me, but I guess they know what they're doing...) and robotic arm is used to try to find them as an exercise for future commercial crew missions. This is the first time I heard of this, has this been mentioned elsewhere? How do they do the examination when most of the TPS is covered by the trunk?

there are two types of TPS on Dragon.
There is Pica-X for the main heatshield, which is for the most part indeed protected by the trunk, and can not be inspected ( except for the side-parts that creep up bit).
There is also SPAM or SpaceX Proprietary Ablative Material for the rest of the capsule; this is the white outer covering across the whole of dragon.

So, two possibilities;
-it was done on the side of the Pica-X
-it was done on part of the SPAm, somewhere higher up on the capsule
both can be inspected.
Based on the fact that the main Pica-X shield is protected by the trunk exactly because you dont want to get it damaged - and you expect the trunk to fulfill this function - it makes conceptually little sense to put damage there, as you would not expect this to be likely in real life. So, i would guess small MMOD-like damage to SPAM or the very upper covering of the Pica-X.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: baldusi on 05/10/2016 10:33 pm
There's another option. They could have put a simulated hole inside the trunk. Right inside where they had the IDA.
They have a lot of experience surveying a TPS from the Shuttle times. But none from inside a trunk. But this is very speculative.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 05/10/2016 11:08 pm
Based on the fact that the main Pica-X shield is protected by the trunk exactly because you dont want to get it damaged - and you expect the trunk to fulfill this function - it makes conceptually little sense to put damage there, as you would not expect this to be likely in real life. So, i would guess small MMOD-like damage to SPAM or the very upper covering of the Pica-X.

With the main docking port for Commercial Crew being the forward port of Node 2, the heat shields for CCrew vehicles will be likewise facing forward.  Does this have an impact on the expected risk of MMOD damage?  Maybe the geometry can help inform a guess about where exactly they're looking?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mtakala24 on 05/11/2016 07:34 pm
Successful splashdown. Has SpaceX ever released a video of CRS mission Dragon splashdown?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 05/11/2016 07:39 pm
Successful splashdown. Has SpaceX ever released a video of CRS mission Dragon splashdown?
They tweeted the photo. No video yet.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jgoldader on 05/11/2016 07:44 pm
Does anybody know if the water infiltration problems from the first couple of flights have been fixed?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mtakala24 on 05/11/2016 07:46 pm
Successful splashdown. Has SpaceX ever released a video of CRS mission Dragon splashdown?
They tweeted the photo. No video yet.

I meant the previous CRS missions.  I don't remember ever seeing a video...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: kevinof on 05/11/2016 07:46 pm
Does anybody know if the water infiltration problems from the first couple of flights have been fixed?

Yes
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: tleski on 05/11/2016 07:48 pm
Successful splashdown. Has SpaceX ever released a video of CRS mission Dragon splashdown?
They tweeted the photo. No video yet.

I meant the previous CRS missions.  I don't remember ever seeing a video...

I don't remember either, let's hope we will see one this time.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Lars-J on 05/11/2016 08:17 pm
Successful splashdown. Has SpaceX ever released a video of CRS mission Dragon splashdown?
They tweeted the photo. No video yet.

I meant the previous CRS missions.  I don't remember ever seeing a video...

CRS-1 splashdown can be seen in this video:
https://www.youtube.com/watch?v=pP-XITSoEwY
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sevenperforce on 05/11/2016 08:28 pm
Successful splashdown. Has SpaceX ever released a video of CRS mission Dragon splashdown?
They tweeted the photo. No video yet.

I meant the previous CRS missions.  I don't remember ever seeing a video...

CRS-1 splashdown can be seen in this video:
Neat to see how much translational motion there is from wind. Obvious why you wouldn't want to try and land a booster that way.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: mtakala24 on 05/11/2016 08:51 pm
Thanks Lars-J!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: jgoldader on 05/11/2016 10:30 pm
Congrats to SpaceX!  Checked off all the boxes on this one, it seems, and you're sure making it fun for the rest of us!
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/11/2016 11:46 pm
Another couple of tons of valuable downmass is retrieved from the ISS - at absolute bargain prices. This is one of my go-to points arguing against people who say that SpaceX has been subsidized; this (currently unique) capability is provided at ultra-low cost to NASA.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Prettz on 05/12/2016 12:06 am
Another couple of tons of valuable downmass is retrieved from the ISS - at absolute bargain prices. This is one of my go-to points arguing against people who say that SpaceX has been subsidized; this (currently unique) capability is provided at ultra-low cost to NASA.
Why even bother arguing against people who claim that's a bad thing?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Rocket Science on 05/12/2016 12:12 am
Congrats SpaceX well done! Thanks to Chris G for the great EOM wrap up! :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 05/12/2016 12:12 am
Another couple of tons of valuable downmass is retrieved from the ISS - at absolute bargain prices.

A little too generous. Hundreds of pounds.  There is a lot trash in there too.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: king1999 on 05/12/2016 01:00 am
Another couple of tons of valuable downmass is retrieved from the ISS - at absolute bargain prices.

A little too generous. Hundreds of pounds.  There is a lot trash in there too.

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: dgates on 05/12/2016 02:19 am
Apologies if this is available elsewhere, but what is max dragon1 down mass capability? Though i suspect they "cube out" before they reach max mass anyway, this is sometimes the case with aircraft.  One just runs out of room before max weight.  Center of gravity considerations could also come into play, of course.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 05/12/2016 03:06 am

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

"Hundreds of pounds" goes up to 1900lb before it becomes a ton.  And multiple vehicles are used for trash, including Dragon.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: king1999 on 05/12/2016 03:21 am

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

"Hundreds of pounds" goes up to 1900lb before it becomes a ton.  And multiple vehicles are used for trash, including Dragon.

I guess it is a case of lost in translation. In my language (non-English), "hundreds" only goes up to 999. More than that we call it "thousand(s)".
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/12/2016 04:23 am
Another couple of tons of valuable downmass is retrieved from the ISS - at absolute bargain prices.

A little too generous. Hundreds of pounds.  There is a lot trash in there too.

Hey, SpaceX isn't dictating what NASA puts in the downmass. They carry it down anyways. :)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Mike_1179 on 05/13/2016 02:01 am

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

Getting rid of trash is a challenge for ISS, you can't just throw something out the window or wash and reuse clothes. Any vehicle leaving gets trash in it, otherwise you have to store it and wait.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: CameronD on 05/13/2016 03:07 am

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

Getting rid of trash is a challenge for ISS, you can't just throw something out the window or wash and reuse clothes. Any vehicle leaving gets trash in it, otherwise you have to store it and wait.

So now Elon's providing a contract laundry service to NASA?!??  It never occurred to me before that maybe it's really the smell of dirty laundry that awaits the lucky first to open Dragon after splashdown.  :o  ;D

"The laundry basket's over on the left there, under those science experiments."

Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 05/13/2016 12:37 pm

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

"Hundreds of pounds" goes up to 1900lb before it becomes a ton.  And multiple vehicles are used for trash, including Dragon.

I guess it is a case of lost in translation. In my language (non-English), "hundreds" only goes up to 999. More than that we call it "thousand(s)".
Even the total mass is "hundreds" as in 37 hundred lbs.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Jim on 05/13/2016 12:39 pm

So now Elon's providing a contract laundry service to NASA?!??


Always was providing that service from Day 1.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: the_other_Doug on 05/13/2016 12:39 pm

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

Getting rid of trash is a challenge for ISS, you can't just throw something out the window or wash and reuse clothes. Any vehicle leaving gets trash in it, otherwise you have to store it and wait.

So now Elon's providing a contract laundry service to NASA?!??  It never occurred to me before that maybe it's really the smell of dirty laundry that awaits the lucky first to open Dragon after splashdown.  :o  ;D

"The laundry basket's over on the left there, under those science experiments."

Since downmass is limited (and, in the case of Dragon and Soyuz, more volume-limited than mass-limited), it seems to me that most of the "trash" thrown out in either craft is used to pack more delicate items.

Think of it as using your old laundry to wrap up your drinking tumblers when you move.  You're not doing it because you need to move the old laundry, you're doing it to protect the delicate glassware.

So, on the Dragons, dirty underwear = bubble wrap... ;)
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: sevenperforce on 05/13/2016 12:53 pm

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

"Hundreds of pounds" goes up to 1900lb before it becomes a ton.  And multiple vehicles are used for trash, including Dragon.

I guess it is a case of lost in translation. In my language (non-English), "hundreds" only goes up to 999. More than that we call it "thousand(s)".
Even the total mass is "hundreds" as in 37 hundred lbs.
To be fair, the original comment was "couple of tons" so hundreds of pounds vs a couple of (short) tons would definitely break at 1999 pounds.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Robotbeat on 05/13/2016 02:11 pm

Did you mean that out of the more than 3700 pounds of down mass, more than 2700 pounds is trash? Why don't they use the Cygnus for trash?

"Hundreds of pounds" goes up to 1900lb before it becomes a ton.  And multiple vehicles are used for trash, including Dragon.

I guess it is a case of lost in translation. In my language (non-English), "hundreds" only goes up to 999. More than that we call it "thousand(s)".
Even the total mass is "hundreds" as in 37 hundred lbs.
To be fair, the original comment was "couple of tons" so hundreds of pounds vs a couple of (short) tons would definitely break at 1999 pounds.
Another way of saying this is that you all are in violent agreement.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Arb on 05/13/2016 11:06 pm
This discusses a waiver SpaceX requested for CRS-8 having to do with ship-borne impact hazard but also mentions the previous ASDS landings and a USAF evaluation of the overall launch hazard.

https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement (https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement)

Would someone who's read it kindly do a TL:DR for the busy, busy. Thanks.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 05/13/2016 11:41 pm
This discusses a waiver SpaceX requested for CRS-8 having to do with ship-borne impact hazard but also mentions the previous ASDS landings and a USAF evaluation of the overall launch hazard.

https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement (https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement)

Would someone who's read it kindly do a TL:DR for the busy, busy. Thanks.

The FAA has a number of risk calculations and thresholds--threshold which you cannot exceed without a waiver (collectively or individually) in order to obtain a launch license.  This waiver is due to one of those risk calculations exceeding a threshold.

The FAA has previously issued several similar waivers to SpaceX and ORB/ATK (among others), and for similar (if not exactly) the same reasons.

FYI... There is an FAA rule change pending that would eliminate the need for some of these waivers, which was first put forth by the FAA in Jul-2014.  For more information than you probably want, see CHANGING THE COLLECTIVE RISK LIMITS FOR LAUNCHES AND REENTRIES AND CLARIFYING THE RISK LIMIT USED TO ESTABLISH HAZARD AREAS FOR SHIPS AND AIRCRAFT (https://www.federalregister.gov/articles/2014/07/21/2014-16928/changing-the-collective-risk-limits-for-launches-and-reentries-and-clarifying-the-risk-limit-used-to).
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Retired Downrange on 05/14/2016 12:33 am
I can see how in the past, the FAA would have a risk threshold for a possible ship impact hazard, but now the object of the test is that SpaceX "AIMS" to hit the ship.

Times change...
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 05/14/2016 12:45 am
I can see how in the past, the FAA would have a risk threshold for a possible ship impact hazard, but now the object of the test is that SpaceX "AIMS" to hit the ship.

I hope that was intended to be humorous (sorry, my humor-meter has been dulled by too much irony of late).  FAA calculation is based primarily on risk to public life-and-limb (Ec); for property they simply demand adequate insurance before granting a launch license.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/14/2016 12:53 am
I can see how in the past, the FAA would have a risk threshold for a possible ship impact hazard, but now the object of the test is that SpaceX "AIMS" to hit the ship.

Times change...

The point for me is that the stage is re-entering under control. SpaceX know where they want it to go, and they clearly have at least an 80% chance of putting it exactly there, which should reduce the remaining area risk by a factor of at least 5.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: joek on 05/14/2016 01:05 am
The point for me is that the stage is re-entering under control. SpaceX know where they want it to go, and they clearly have at least an 80% chance of putting it exactly there, which should reduce the remaining area risk by a factor of at least 5.

Hmmm... not sure about that "80% chance of putting it exactly there..." (where does that come from?).  But the FAA seems to be convinced that SpaceX can put it where they want it, as the most recent launch licenses includes "Flight includes landing of the Falcon 9 Version 1.2 first stage as indicated in the license application.".  That was notably absent from any prior FAA launch licenses; probably a good sign.  But even if, as you say, it "should reduce the remaining area risk by a factor of at least 5", it was not enough-and is not enough under current rules--to eliminate the need for a waiver.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: OxCartMark on 05/14/2016 02:57 am
Hmmm... not sure about that "80% chance of putting it exactly there..." (where does that come from?).
Prior to the grid fin addition during the period that we were made aware of their retro propulsion recovery attempts I don't believe that there were any ocean returns that were not within 10km of the intended point, about as good as you could expect in that configuration.  Since the addition of the grid fins we've had (off the top of my head) 7 aimed at the ASDS and every one of them has made some sort of contact with the ASDS except for once when the ASDS was out of position and even then the F9 was reported to have gone to the right spot.  Additionally we've had one RTLS which did get to the LZ-1.  8 of 8 is on the surface greater than 80% though Its been a long while since I had probability and statistics, maybe there's something that wasn't demonstrated to a specific confidence level yet??
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: baldusi on 05/14/2016 03:07 am
First you have to assume the probability of failure all over the trajectory, to and (now) from space. Second the probability of killing someone is atrociously low.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 05/14/2016 08:53 am
Moving Discussion from Updates thread to proper place: 

This discusses a waiver SpaceX requested for CRS-8 having to do with ship-borne impact hazard but also mentions the previous ASDS landings and a USAF evaluation of the overall launch hazard.

https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement (https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement)

To be clear:  THIS WAIVER IS NOT DIRECTLY RELATED TO LANDING ON ASDS.  If it was for ASDS landings, then similar waivers would have been needed for every previous ASDS landing attempt.

Here's the most relevant part: 

Quote from: Federal Register
The FAA found that small boats (too small to have AIS required) located close to the launch point should not produce significant individual risks, given conditions expected in the vicinity of Cape Canaveral. Specifically, sufficient surveillance with other means (e.g., radar, and/or using Coast Guard ships or aerial assets) will be used to ensure individual risks comply with the FAA requirement in § 417.107(b)(2). In addition, Notices to Mariners will continue to be issued for the areas where the probability of impact on a ship would exceed 1 × 10 −5, which is current practice at the ER, and required by §§ B417.3 and B417.11. Since the FAA's current requirements allow launches to proceed with unquantified residual collective risks to people in waterborne vessels, as long as the collective risk for people on land from each source of hazard (i.e., debris, toxics, or distant focusing overpressure) does not exceed 30 × 10 −6 E C, and because the launch will not exceed the 30 × 10 −6 E C with the inclusion of persons on water borne vessels, the FAA finds that the Falcon 9 CRS-8 launch will not jeopardize public health and safety or safety of property, and waives 14 CFR 417.107(b)(3) and Appendix B to part 417, paragraph 417.5(a)'s requirement not to initiate flight absent evacuation.

A more nuanced reading, and the part that could be relevant for ASDS landings, is that it might allow them to stage the recovery support vessels (Go Quest and tug) closer to the ASDS during landings.  i.e. Instead of making them wait 5-7miles away, they might only have to wait 2-3 miles.  This would reduce the time needed to return landed stages to port.  But, without reading SpaceX's actual application, it's hard to understand exactly what they were arguing.  The gist from the Federal Register is that AIS and ship tracking data is sufficient now to determine the Ec including shipboard persons as opposed to just trying to determine the odds of hitting a ship with debris.  And, SpaceX would like to do that as they feel like they're less likely to be forced to scrub a launch by a late intrusion into the hazard area unless the ship in question happens to be a large, passenger carrier. 

NB: This doesn't mean that they wouldn't try to keep any boats/ships out of the hazard zone, including using Coast Guard assets to convince them to GTFO.

TL;DR- A repeat of the SES-9 scrub due to a late intrusion by a barge being towed into the hazard zone isn't going to happen.  Only a large passenger ship (e.g. a cruise ship) going into the hazard zone would be likely to warrant scrubbing the launch.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: Joffan on 05/14/2016 11:10 am
To be clear:  THIS WAIVER IS NOT DIRECTLY RELATED TO LANDING ON ASDS.  If it was for ASDS landings, then similar waivers would have been needed for every previous ASDS landing attempt.

Right. However note that success in steering the descending stage means that the hazard for the rest of the descent zone would be zero. To make a sensible risk assessment for the rest of that zone, therefore, you need to scale down by the chance of a total failure of that steering. Given the recent successful track record, I resort to my usual rule of thumb of assuming that the next stage descent fails to steer to make a conservative guess at that probability.

A more nuanced reading, and the part that could be relevant for ASDS landings, is that it might allow them to stage the recovery support vessels (Go Quest and tug) closer to the ASDS during landings.  i.e. Instead of making them wait 5-7miles away, they might only have to wait 2-3 miles.  This would reduce the time needed to return landed stages to port.  But, without reading SpaceX's actual application, it's hard to understand exactly what they were arguing.  The gist from the Federal Register is that AIS and ship tracking data is sufficient now to determine the Ec including shipboard persons as opposed to just trying to determine the odds of hitting a ship with debris.  And, SpaceX would like to do that as they feel like they're less likely to be forced to scrub a launch by a late intrusion into the hazard area unless the ship in question happens to be a large, passenger carrier. 

Justifying a reduction in the support  boat offset is tricky to judge for us bystanders. SpaceX will have the data on the trajectory control and how early they bring the impact point  in close to the ASDS. But  I agree with the reading that this is mainly about reducing scrub likelihood due to hazard area incursion.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: cscott on 05/14/2016 11:32 am
This discusses a waiver SpaceX requested for CRS-8 having to do with ship-borne impact hazard but also mentions the previous ASDS landings and a USAF evaluation of the overall launch hazard.

https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement (https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement)

Would someone who's read it kindly do a TL:DR for the busy, busy. Thanks.
TL:DR: Previously calculating the actual probability of impact on a ship and subsequent loss of life was difficult, so the rule was written as "no launching if there are ships in a hazard zone".  The USCG mandate to have AIS transponders on ships above a certain size has allowed the range to develop a more sophisticated approach, where you can compute in real time the probability of human casualty using the known maximum human capacity and location of the AIS-carrying ships and some assumptions about small non-AIS-carrying ships.  This allows a uniform treatment of potential casualties on land and sea.

SpaceX requested a general waiver back in January to use this new casualty-estimation process.  They were then encouraged to request a specific exemption for CRS-8 after the tug boat scrubbed the launch of SES-9, since presumably in that particular case the launch would not have been scrubbed under the new rules since the tugboat had a very small crew and so the risk of casualty would have been sufficiently low.

There seems to be more general rulemaking in progress to make this new standard the default, but the FAA seems willing to give individual flights waivers to use it for now.
Title: Re: SpaceX Falcon 9 - CRS-8 Dragon - NET April, 2016 - DISCUSSION
Post by: deruch on 05/15/2016 12:12 am
This discusses a waiver SpaceX requested for CRS-8 having to do with ship-borne impact hazard but also mentions the previous ASDS landings and a USAF evaluation of the overall launch hazard.

https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement (https://www.federalregister.gov/articles/2016/05/10/2016-09685/waivers-of-ship-protection-probability-of-impact-requirement)

Would someone who's read it kindly do a TL:DR for the busy, busy. Thanks.
TL:DR: Previously calculating the actual probability of impact on a ship and subsequent loss of life was difficult, so the rule was written as "no launching if there are ships in a hazard zone".  The USCG mandate to have AIS transponders on ships above a certain size has allowed the range to develop a more sophisticated approach, where you can compute in real time the probability of human casualty using the known maximum human capacity and location of the AIS-carrying ships and some assumptions about small non-AIS-carrying ships.  This allows a uniform treatment of potential casualties on land and sea.

SpaceX requested a general waiver back in January to use this new casualty-estimation process.  They were then encouraged to request a specific exemption for CRS-8 after the tug boat scrubbed the launch of SES-9, since presumably in that particular case the launch would not have been scrubbed under the new rules since the tugboat had a very small crew and so the risk of casualty would have been sufficiently low.

There seems to be more general rulemaking in progress to make this new standard the default, but the FAA seems willing to give individual flights waivers to use it for now.

Good summary! 

For those wondering, the assumptions that they are using for this new calculation are that the ships have the maximum number of passengers possible and they are not adjusting for reasonable % of them actually being on deck (i.e. no protection from being below decks).  So, all told, a pretty conservative set of assumptions.