Author Topic: SpaceX: General Falcon and Dragon discussion (Thread 7)  (Read 342480 times)

Offline Jim

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #860 on: 03/14/2013 01:04 AM »
1.  Looks like enough room for 2 folks to lie on their backs with their knees up; maybe 3 if the side part is flat.
2. Apollo 13 survived with no heat, and they don't need water since the air will run out first.
3 Straight extrapolation to 3 people, 10 cubic meters of Dragon gives 8.77 hours.  These folks would be more excited, so say 5-6 hours.

4.  So can they land somewhere, in water, where someone can get them out

5. within this time?  I guess yes.  Each orbit must cross North or South America somewhere.  This gives you two coasts to aim for.  All these countries have navies with helicopters.  With GPS and big parachutes it should be possible to find the capsule fairly easily, hopefully on the way down.  It's OK to open the capsule destructively in this case, so tools should not be problem.


None are valid

1.  "Looks like" doesn't mean it is, which it isn't
2.  The problem is the opposite, heat and water need to be removed from the air
3.  10 m3 is for an empty capsule without racks.  Also, wrong subjects for extrapolation.  There are two strikes, lack of fitness and excitation.
4.  it is an emergency and picking a landing spot is not a given.  Also, the high inclination of the orbit does put it out of the reach of coastal helicopters

Online QuantumG

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #861 on: 03/14/2013 01:08 AM »
Okay, I've done report to mod three times on this thread already. Obviously the mods disagree with me, so I'll just whine instead.

I'm sorry I answered a newbie's question. I didn't think it would result in all this rehashing and speculative ISS disaster fiction.

Does anyone have anything Falcon or Dragon to talk about?
I hear those things are awfully loud. It glides as softly as a cloud. What's it called? Monowhale!

Online QuantumG

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #862 on: 03/14/2013 01:23 AM »
Is the concept of "general discussion" unknown to you, or is whining always on-topic?

Fair enough.. guess I don't have to read every thread.
I hear those things are awfully loud. It glides as softly as a cloud. What's it called? Monowhale!

Online oiorionsbelt

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #863 on: 03/14/2013 02:18 AM »
Is the concept of "general discussion" unknown to you, or is whining always on-topic?

Fair enough.. guess I don't have to read every thread.

Sure you do because someone may add bit of info you didn't know before. For example I suggested un-berthing dragon required astros on the station. To which robotbeat replied it can be controlled from the ground. To which Jorge replied only preprogrammed ops can be done from the ground but not berthing/ un-birthing. I didn't know that and only found out by discussing something that pretty much everyone says isn't realistic  :)

Offline LouScheffer

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #864 on: 03/14/2013 02:47 AM »
1.  Looks like enough room for 2 folks to lie on their backs with their knees up; maybe 3 if the side part is flat.
2. Apollo 13 survived with no heat, and they don't need water since the air will run out first.
3 Straight extrapolation to 3 people, 10 cubic meters of Dragon gives 8.77 hours.  These folks would be more excited, so say 5-6 hours.

4.  So can they land somewhere, in water, where someone can get them out

5. within this time?  I guess yes.  Each orbit must cross North or South America somewhere.  This gives you two coasts to aim for.  All these countries have navies with helicopters.  With GPS and big parachutes it should be possible to find the capsule fairly easily, hopefully on the way down.  It's OK to open the capsule destructively in this case, so tools should not be problem.


None are valid

1.  "Looks like" doesn't mean it is, which it isn't
2.  The problem is the opposite, heat and water need to be removed from the air
3.  10 m3 is for an empty capsule without racks.  Also, wrong subjects for extrapolation.  There are two strikes, lack of fitness and excitation.
4.  it is an emergency and picking a landing spot is not a given.  Also, the high inclination of the orbit does put it out of the reach of coastal helicopters
1.  Quite possible, data is needed to settle this.  What *are* the sizes?  I looked and could not find them.  Remember, the astronauts can remove the packages from the layer nearest the heat shield if that gives them more surface.
2.  The cargo dragon is specified to supply 1500-2000 watts to the cargo; therefore they must be able to dissipate this without exceeding their max temp of 46 C.  (See http://wsn.spaceflight.esa.int/docs/Factsheets/28%20SpaceXDragon%20LR.pdf for cargo power, http://www.spaceflight101.com/dragon-spacecraft-information.html for cabin temp)  Three resting people will add about 300 watts.  The temperature control should handle this easily.
3) Assuming 1000kg of stuff at an average density of 1, the stuff takes up only 1 m^3 of volume.  That's 10% less air, but we left out an opposite factor of 10% since Houdini/Randi took up 10% of their coffins.  Fitness and excitation are reasonable, but presumably astronauts are as rational as Houdini and Randi and will remain as still as possible.  My proposal was that, all things considered, they were 50% more active than Houdini or Randi.  What number do you think is reasonable?
4) North America extends past the northmost excursion of the ISS orbit, and South America below the southmost.  Therefore every orbit must cross both the East and West coast of one of the Americas.   There are no restrictions that I am aware of as to where you perform your de-orbit burns, so you can land as close as you want to either coast, subject only to not wanting to hit land.  For North America the coastal cities, and Coast Guard bases, are close enough together you can surely get a helicopter there in time.  South America is iffier, but it's an emergency and you take your chances (and many of orbits that cross South America then cross Western Europe, where the coast is dense with cities).  You can also drop Seals or their equivalent, equipped with can-openers, from cargo planes if helicopters cannot reach or are too slow.

Offline Zed_Noir

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #865 on: 03/14/2013 06:46 AM »
4.  So can they land somewhere, in water, where someone can get them out

4.  it is an emergency and picking a landing spot is not a given.  Also, the high inclination of the orbit does put it out of the reach of coastal helicopters

Ahem. Why are we talking helos. They aren't the fastest aircraft around.

One alternative is to drop para-frogmen out of a C130 or C17 transport first then emergency gear afterwards. The para-frogmen secure the capsule with flotation support gear and wait for the recovery ship.

Another alternative  is to drop the para-frogmen from V-22 VTOL aircraft if the capsule lands near to a V-22 base or operations platform.


Offline guckyfan

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #866 on: 03/14/2013 08:24 AM »
A completely different topic.

Assuming that SpaceX can produce enough launch vehicles the launch sites become the limiting factor.

Vandenberg is not suitable for all trajectores. The large majority will launch at CCAFS How many flights a year out of CCAFS are realistic? I have not seen a discussion dedicated to this, just some general remarks. Apologies if I missed it.

« Last Edit: 03/14/2013 08:25 AM by guckyfan »

Offline Galactic Penguin SST

A completely different topic.

Assuming that SpaceX can produce enough launch vehicles the launch sites become the limiting factor.

Vandenberg is not suitable for all trajectores. The large majority will launch at CCAFS How many flights a year out of CCAFS are realistic? I have not seen a discussion dedicated to this, just some general remarks. Apologies if I missed it.



My guess is once a month - this is roughly the launch pace Ariane 4 has maintained in the 1990s. But that depends on how large the market share SpaceX has managed to catch.....
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline douglas100

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #868 on: 03/14/2013 09:06 AM »
I think one a month might be a bit optimistic with the current infrastructure.

At the moment the size of the hangar and its proximity to the pad means that they can only prepare one vehicle at a time. This could become a bottleneck if the flight rate goes up. As it stands, the launch campaign would have to be well under 30 days to achieve this kind of flight rate. I imagine that as they gain experience, the length of the campaign will come down.
Douglas Clark

Offline Ben the Space Brit

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #869 on: 03/14/2013 09:25 AM »
A completely different topic.

Assuming that SpaceX can produce enough launch vehicles the launch sites become the limiting factor.

Vandenberg is not suitable for all trajectores. The large majority will launch at CCAFS How many flights a year out of CCAFS are realistic? I have not seen a discussion dedicated to this, just some general remarks. Apologies if I missed it.

I would say any given pad at CCAFS will max out at 12 launches a year with an average interval of 4 weeks.  This only becomes a problem if SpaceX has any missions that require a dual launch for any reason.

That said, I agree with Douglas about the bottleneck of the HIF and Hanger AO.  At present, if you've got two sequential FH flights lined up, you're looking at a big delay.

Hmm...

Is the old Titan VAB up the crawlway from SLC-40 and -41 still there?
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Offline padrat

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #870 on: 03/14/2013 10:34 AM »
From what I've been told the 1.1/FH cores are too long to fit in AO for processing. The 1.1 stages are supposed to come to us practically complete so should be less time to process than in the past. Besides, there may be other future plans for AO anyways.....

The Titan structures (SMAB/SMARF) are still there as well. Could be plans for one of those as well, nothing concrete yet... not 1st stage or core processing from what I've heard..
« Last Edit: 03/14/2013 10:38 AM by padrat »
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Offline Herb Schaltegger

1.  Looks like enough room for 2 folks to lie on their backs with their knees up; maybe 3 if the side part is flat.
2. Apollo 13 survived with no heat, and they don't need water since the air will run out first.
3 Straight extrapolation to 3 people, 10 cubic meters of Dragon gives 8.77 hours.  These folks would be more excited, so say 5-6 hours.

4.  So can they land somewhere, in water, where someone can get them out

5. within this time?  I guess yes.  Each orbit must cross North or South America somewhere.  This gives you two coasts to aim for.  All these countries have navies with helicopters.  With GPS and big parachutes it should be possible to find the capsule fairly easily, hopefully on the way down.  It's OK to open the capsule destructively in this case, so tools should not be problem.


None are valid

1.  "Looks like" doesn't mean it is, which it isn't
2.  The problem is the opposite, heat and water need to be removed from the air
3.  10 m3 is for an empty capsule without racks.  Also, wrong subjects for extrapolation.  There are two strikes, lack of fitness and excitation.
4.  it is an emergency and picking a landing spot is not a given.  Also, the high inclination of the orbit does put it out of the reach of coastal helicopters

2.  The cargo dragon is specified to supply 1500-2000 watts to the cargo; therefore they must be able to dissipate this without exceeding their max temp of 46 C.  (See http://wsn.spaceflight.esa.int/docs/Factsheets/28%20SpaceXDragon%20LR.pdf for cargo power, http://www.spaceflight101.com/dragon-spacecraft-information.html for cabin temp)  Three resting people will add about 300 watts.  The temperature control should handle this easily.

There's a difference between dissipating heat loads from rack-mounted equipment connected to active thermal control loops and removing heat  from the ambient air, which must be evenly and fully circulated throughout the entire volume of the pressurized cabin.
« Last Edit: 03/14/2013 11:23 AM by Herb Schaltegger »
Ad astra per aspirin ...

Offline guckyfan

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #872 on: 03/14/2013 11:35 AM »
Thanks for the replies. I could have imagined that there is no simple answer. Could someone please tell me what AO stands for?

Yes I was looking for dual launch missions beside total capacity. Exciting things could be done with two FH launches. But that would require two independent pads, I imagine.


Offline Ben the Space Brit

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #873 on: 03/14/2013 11:38 AM »
The Titan structures (SMAB/SMARF) are still there as well. Could be plans for one of those as well, nothing concrete yet... not 1st stage or core processing from what I've heard..

Sorry, I'm silly but I've just had a mental image of that building with all its high bay doors open with a row of FHs and F9s ready to be rolled out. :D


Could someone please tell me what AO stands for?

'AO' is just the building designation.  As ugordan mentions below, it's previous role was a storage facility for Delta-IIs.


[edit]
Replied to guckyfan
« Last Edit: 03/14/2013 11:40 AM by Ben the Space Brit »
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Offline ugordan

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Offline go4mars

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #875 on: 03/14/2013 02:36 PM »
That is the larger group of women at SpaceX - They made a separate picture of just the women engineers - you can see that here:

https://twitter.com/SpaceX/status/304699525635907584/photo/1
That needs to appear here:  http://shop.spacex.com/  as a poster.  To inspire young women...     

I'll stop there.  Please do likewise.
« Last Edit: 03/14/2013 05:30 PM by go4mars »
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Offline Jim

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #876 on: 03/14/2013 03:55 PM »

Is the old Titan VAB up the crawlway from SLC-40 and -41 still there?

It was torn down

Offline sheltonjr

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #877 on: 03/15/2013 02:42 PM »
Popular science April edition has a "How it works"  issue. The Front cover is the Falcon Heavy.

Link is here:http://www.popsci.com/science/article/2013-03/most-powerful-space-rocket

The surprise that I do not think I have heard before is that cross-feed is not used unless the payload is over 100,000 lbs. 

PopSci Quote:
Quote
2) FIRST STAGE: THREE ROCKET CORES
Falcon Heavy’s first stage consists of three cores. All three cores operate together at liftoff. About T+2:45 minutes into flight, the center core throttles down while the two side cores continue at full thrust until their fuel is nearly spent. At that point, pneumatic separators release the side cores, which plummet into the ocean, and the center core throttles up.

3) CENTER CORE
For payloads heavier than 100,000 pounds, Falcon Heavy uses a cross-feed system to run fuel from the side cores to the center core, leaving the center core almost fully fueled after the side boosters separate. What’s left is the equivalent of a complete Falcon 9 rocket already high in space.

And then later it has the time line that shows center core throttling down 15 sec before side cores burn out and the center only burns for 30 seconds extra.

Quote
T + 0:02:45
The rocket has now burned enough fuel (thus decreasing its mass) that the center core engines can throttle down.

T + 0:03:00
The side cores separate and fall into the ocean, while the center core’s nine Merlin engines continue to burn for approximately 30 seconds.

T + 0:03:30
The second stage separates from the remaining first-stage core. The second-stage engine ignites and continues toward orbit.

Does this all make sense?

So, with all the complications added for the cross-feed is only for the benefit of an extra 17,000 lbs.

I was thinking one of the benefits of the cross-feed once re usability starts it to burn the side cores quickly so they are not a downrange and have a little reduced velocity to get the cores turned around and headed back to the launch pad. Maybe the FHR will change all the above.

Offline baldusi

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #878 on: 03/15/2013 03:19 PM »
I wouldn't take whatever they wrote with a grain of salt. The higher energy orbits would benefit more from cross feeding than the lower orbits. But to give you an idea, according to ULA, using cross feeding would give 5 extra tonnes. Which was about an extra 20%. Of course the Delta IV doesn't have such a good T/W so the gravity losses are greater.

Offline smoliarm

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Re: SpaceX: General Falcon and Dragon discussion (Thread 7)
« Reply #879 on: 03/15/2013 04:58 PM »
Popular science April edition has a "How it works"  issue. The Front cover is the Falcon Heavy.

Link is here:http://www.popsci.com/science/article/2013-03/most-powerful-space-rocket

PopSci Quote:
...

Does this all make sense?

...

Yes. Obviously they give timeline for the case with NO cross-feed -- otherwise it would take center core about 3 min. to burn the full tanks dry.

Quote
So, with all the complications added for the cross-feed is only for the benefit of an extra 17,000 lbs.
It's not "only" 17,000 lbs, it's bold 17%. Pretty close to the number baldusi quoted.
 
Quote
The surprise that I do not think I have heard before is that cross-feed is not used unless the payload is over 100,000 lbs. 
Think of cross-feed as of SRBs on Atlas or Delta: you won't use SRB if there is no need, they cost money.

And thanks for the link, I've seen the pictures, but not the time line.
By this time line, they use 91.6% fuel in side boosters. Looks like these 8.4% are for powered reentry
:)

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