Crewed Dragon safety question

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PJay_A

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By all probability, it is now safe to assume that American astronauts will use a crewed version of SpaceX' Dragon capsul for lifts to the space station. My quesion: has an emergency jetison system been developed for Dragon that would propel the capsul to a safe distance from the launch system in the event of an emergency? I know one was being developed for Orion. Had the shuttles had such a system, the crew of Challenger might have been rescued.
 
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mr_mark

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Good Question! From what I've heard from the industry, Spacex has developed the System for their LAS. They are awaiting funding from NASA to build and test their system. Funding won't probably come through until 2011 though, so Spacex will continue to work on Cargo based deployment of Dragon and their Falcon 9 launch vehicle. This years funding from NASA went to companies that needed to get R&D off the ground. Spacex already had the funding to develop Dragon so they were not included in this round of funding. When the next round of funding comes they are expected to get a share of that for building and testing of their LAS. NASA funding will come in stages though so don't expect them to plot down the whole amount Spacex needs in one year.
 
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mj1

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I had also seen somewhere that a pressurized Dragon would be docked to the station long term to be used as an escape vehicle, since one can stay attached to the station for up to 6 months. Any of you more informed guys seen this anywhere? Is that not something that the Dragon would be able to do sooner rather than later? Don't need an LAS to use a Dragon for an escape capsule.
 
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EarthlingX

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They could use what NASA have, if that's allowed ? Put NASA LAS on Dragon, it would be probably faster than going from the scratch.
If they claim they can make their own in 3 years, this should be even faster, and if i understand it correctly, LAS is the show stopper at the moment, at least for people.

They will have to bring some cargo up, before this becomes a serious topic, but i think it has good chances to be solved sooner.
 
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docm

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One of Blue Origin's jobs is the development of a relatively inexpensive "pusher" LAS system that would fit between the 2nd stage and spacecraft, presumably a pancake type of affair. It they succeed in that it could probably be used with capsules or attached to the bottom of Dream Chaser's booster adapter. The HL-20's LAS consisted of solids mounted around said adapters perimeter; HL-20 being what the DC is based on.

Bolden's comments make it clear they want redundancy, not wanting to repeat the experiences we had after Challenger and Columbia, and having a space-plane and capsule covers a lot of bases. I see Orion Lite as plan-B if Dragon doesn't work out, this because as of now O-Lite is more paper than capsule and Dragon is prepping to fly.
 
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stevekk

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Space X will definately not be using the LAS system developed for the Orion / Ares combination.

The guy from Lockhead Martin mentioned they had completed the LAS design for Orion. I thought he mentioned something like a launch weight of 11,000 lbs or Kg. I don't really remember the units, but it has significant weight. The weight of the LAS most likely exceeds the current lift capacity of the Falcon 9.

Of course, NASA would also like any crewed vehicle to have some micro-meteriod protection, and radiation shielding, both of which are going to add additional weight to the capsule.

Let's wait and see if SpaceX can reliably do Cargo before we start thinking about the next step.
 
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voyager4d

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stevekk":2l7jl8t0 said:
Of course, NASA would also like any crewed vehicle to have some micro-meteriod protection, and radiation shielding, both of which are going to add additional weight to the capsule.

This should already be in place in the cargo version, remember it is going to be docked with the spacestation, and crew will need to go inside. So in that sense it will already be human rated..
But of course it still need some life support systems and the much talked about escape system.
 
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shuttle_guy

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PJay_A":hmlf46sm said:
By all probability, it is now safe to assume that American astronauts will use a crewed version of SpaceX' Dragon capsul for lifts to the space station. My quesion: has an emergency jetison system been developed for Dragon that would propel the capsul to a safe distance from the launch system in the event of an emergency? I know one was being developed for Orion. Had the shuttles had such a system, the crew of Challenger might have been rescued.

They have not done much design work on an escape system due to the lack of available funds. I understand that NASA is planning to give them some addition funds to start that work.
 
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shuttle_guy

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EarthlingX":1pjkt0fn said:
They could use what NASA have, if that's allowed ? Put NASA LAS on Dragon, it would be probably faster than going from the scratch.
If they claim they can make their own in 3 years, this should be even faster, and if i understand it correctly, LAS is the show stopper at the moment, at least for people.

They will have to bring some cargo up, before this becomes a serious topic, but i think it has good chances to be solved sooner.

The NASA Orion LES is 23,000 pounds ! Not good for the Falcon 9/Dragon. Plus it is way too powerful for the Dragon. The LES for the Dragon will have to be a new design.
 
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vulture4

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No LAS has ever been used in flight. Gemini did not even have a LAS. It had ejection seats but the astronauts doubted that any ejection was survivable and did not use them even in an on-pad shutdown.

A LAS only saved one crew, on Soyuz, and in that case only because a fire was visible long before the explosion. If the fire had started a little earlier in the count ground personnel would have been killed, with or without the LAS. The Soyuz LAS also caused a fatal ground accident. No US rocket has ever simply burst into flames on the pad prior to launch. The only US crew lost during launch, Challenger, was almost a quarter century ago, and the failure mode was corrected.

The big problem I have is with people shooting from the hip and claiming that the LAS eliminates all or even any significant part of the risk. It helps only in a narrow spectrum of contingencies which are extremely rare. There are other risks in being an astronaut; at least six were killed in aircraft accidents, including Yuri Gargarin, the first man in space. It's more realistic to thoroughly test designs at the prototype stage and eliminate the failure modes. This is the approach Rutan is taking; his passengers will not have to wear parachutes or pressure suits. One of the astronauts was killed in a crash while simly riding as a passenger on an airliner; occasionally there is an airline crash that kills hundreds. The probable cause is identified, directives are issued, and people pack onto airliners of the same type within days, and without parachutes or escape rockets.

Most likely Dragon will be required to have a LAS, not because there is any actual failure data showing it is needed, but because the assessments of NASA "safety experts" are based on simply making a list of every major component, assuming that it will fail, without actually identifying the failure mode, and creating some "rescue" procedure that will, on paper at least, be followed if it does, thus magically eliminating all risk. If anyone with real training in reliability engineering thinks this is a legitimate strategy please speak up. Several astronauts were killed in aircraft that had ejection seats; how come they were not saved by the "escape" procedure?

At least the Dragon LAS can be much smaller than the Orion monster because the Falcon doesn't have obsolete solid fuel boosters, so the booster will shut down and not try to run over the capsule while it is separating, and the capsule itself is much lighter because it doesn't have to go to the Moon.
 
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DarkenedOne

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vulture4":3lyd99dk said:
No LAS has ever been used in flight. Gemini did not even have a LAS. It had ejection seats but the astronauts doubted that any ejection was survivable and did not use them even in an on-pad shutdown.

A LAS only saved one crew, on Soyuz, and in that case only because a fire was visible long before the explosion. If the fire had started a little earlier in the count ground personnel would have been killed, with or without the LAS. The Soyuz LAS also caused a fatal ground accident. No US rocket has ever simply burst into flames on the pad prior to launch. The only US crew lost during launch, Challenger, was almost a quarter century ago, and the failure mode was corrected.

The big problem I have is with people shooting from the hip and claiming that the LAS eliminates all or even any significant part of the risk. It helps only in a narrow spectrum of contingencies which are extremely rare. There are other risks in being an astronaut; at least six were killed in aircraft accidents, including Yuri Gargarin, the first man in space. It's more realistic to thoroughly test designs at the prototype stage and eliminate the failure modes. This is the approach Rutan is taking; his passengers will not have to wear parachutes or pressure suits. One of the astronauts was killed in a crash while simly riding as a passenger on an airliner; occasionally there is an airline crash that kills hundreds. The probable cause is identified, directives are issued, and people pack onto airliners of the same type within days, and without parachutes or escape rockets.

Most likely Dragon will be required to have a LAS, not because there is any actual failure data showing it is needed, but because the assessments of NASA "safety experts" are based on simply making a list of every major component, assuming that it will fail, without actually identifying the failure mode, and creating some "rescue" procedure that will, on paper at least, be followed if it does, thus magically eliminating all risk. If anyone with real training in reliability engineering thinks this is a legitimate strategy please speak up. Several astronauts were killed in aircraft that had ejection seats; how come they were not saved by the "escape" procedure?

At least the Dragon LAS can be much smaller than the Orion monster because the Falcon doesn't have obsolete solid fuel boosters, so the booster will shut down and not try to run over the capsule while it is separating, and the capsule itself is much lighter because it doesn't have to go to the Moon.

My thoughts exactly.

All this comes down to is the risk adverse nature of NASA that makes everything super expensive and unpractical. LAS has only worked once in the hundreds of flights in the history of HSF.

Now consider the cost of having the LAS on each flight. The LAS weighs about 2500kg as I understand it. At the standard government rate of about $30,000 per pound to LEO that comes out to be 75 million just for LAS alone. That is $7.5 billion. Of course I am sure that when you factor in the development costs it is at least twice that, especially since they have to escape from a powerful solid rocket booster that they cannot turn off.

Now suppose Ares I turns out to be no safer than the shuttle. The shuttle has flown about 130 times and only failed during launch once, so its failure rate is 1 in every 130 launches. Well lets calculate what it would cost to have the LAS on each one of those flights. 130 x $75,000,000 = $9,750,000,000 That is 9,750,000,000 spent in order to save the lives of 4 people.

Now suppose that Ares I achieves its estimated LOM rate of 1 in every 400. Do the same calculation. 400 x $ 75 million = $30 billion. That is $30 billion to save 4 astronauts lives.

Fact of that matter is that in order to have practical HSF we need to start building rockets that just do not fail. Does the airline industry have ejections seats and parachutes for all their passengers? Do they have ejection seats at all? No because they only have a few accidents for every 1,000,000 flights. I do not believe that the rocket industry will be achieving that level of reliability any time soon, however if your rocket has a LOM rating of less the 1 in every 100 flights than having a LAS is not worth it.
 
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menellom

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Tech like LAS all really just come down to producing the illusion of safety. Realistically there's probably something like a 1-5% chance of you blowing up or breaking apart or what have you when you go on a mission into space. Space exploration is an extremely dangerous endeavor, and if the majority of the public's concerns about safety (okay, the minority of the public that actually knows we have a space program :?) couldn't be easily dismissed by installing hypothetically useful safety systems like LAS, what little support for HSF that remains would vanish because "it wouldn't be safe" "why are we sending astronauts to die?" blah blah, basically imagine the kind of post-Challenger/Columbia rhetoric but 24/7.
 
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