Being capable of seating 7 is not the same as being able to support 7, nor having enough room for stowage of space suits and other cargo. NASA is concerned that having more than 4 is impractical for various reasons. (they are running tests on ISS now with 4 of the crew to see how much room there is)
So since NASA only wanted a crew of 4, it is possible that some of the life support currently only supports 4 crew. (just like landing on land was de-scoped because NASA did not want it)
But this is a Starliner thread...
If I remember correctly, both Dragon and Starliner are capable of supporting a 7-crew compliment. But NASA only wants flights to the ISS to carry 4 because that would keep the station at its full 7-crew compliment when the VVs are aboard (3 from ISS and 4 from the VV). When Shuttle was docked with 7 crew space was limited and often uncomfortable, and Shuttle crew berthed aboard the Shuttle. While ISS is capable of supporting more than 7 persons for a short while, it does tax all the systems, which are designed for nominal operations to support 7 persons aboard at a time.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
Get as comfortable as they can and hope for the best. Staying aboard ISS when an evacuation is mandatory is not an option.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
Get as comfortable as they can and hope for the best. Staying aboard ISS when an evacuation is mandatory is not an option.
This is a great topic. Are there any public documents on such a contingency for Starliner? There has got to be a plan. Same question goes for Crew Dragon.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
Get as comfortable as they can and hope for the best. Staying aboard ISS when an evacuation is mandatory is not an option.
This is a great topic. Are there any public documents on such a contingency for Starliner? There has got to be a plan. Same question goes for Crew Dragon.
When/if there are 2 U.S. visiting vehicles, don't crew store their own specific IVA suits on the vehicle they arrive in? If so, wouldn't each crew member need to bug out to their specific capsule to have best chance for survival?
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
Get as comfortable as they can and hope for the best. Staying aboard ISS when an evacuation is mandatory is not an option.
This is a great topic. Are there any public documents on such a contingency for Starliner? There has got to be a plan. Same question goes for Crew Dragon.
When/if there are 2 U.S. visiting vehicles, don't crew store their own specific IVA suits on the vehicle they arrive in? If so, wouldn't each crew member need to bug out to their specific capsule to have best chance for survival?
If they can each use their own vehicle, that's optimal, nobody would argue with that.
But I think the subject under discussion right now is what happens when that's not an option.
If the situation on the station is bad and they need to get off, you can cram everyone into one vehicle. Even if they don't have suits, or even proper seats, they are very likely to survive, which is better than staying on the station to face certain death.
Being capable of seating 7 is not the same as being able to support 7, nor having enough room for stowage of space suits and other cargo. NASA is concerned that having more than 4 is impractical for various reasons. (they are running tests on ISS now with 4 of the crew to see how much room there is)
So since NASA only wanted a crew of 4, it is possible that some of the life support currently only supports 4 crew. (just like landing on land was de-scoped because NASA did not want it)
But this is a Starliner thread...
If I remember correctly, both Dragon and Starliner are capable of supporting a 7-crew compliment. But NASA only wants flights to the ISS to carry 4 because that would keep the station at its full 7-crew compliment when the VVs are aboard (3 from ISS and 4 from the VV). When Shuttle was docked with 7 crew space was limited and often uncomfortable, and Shuttle crew berthed aboard the Shuttle. While ISS is capable of supporting more than 7 persons for a short while, it does tax all the systems, which are designed for nominal operations to support 7 persons aboard at a time.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
I read somewhere(don't remember where) that Astronauts had requested changes to 4 seats positions which meant extra 3 couldn't be fitted. This is nothing to do with NASA requirement for 4 seats.
I may of miss understood the article, would be good to here from somebody in know.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
Get as comfortable as they can and hope for the best. Staying aboard ISS when an evacuation is mandatory is not an option.
This is a great topic. Are there any public documents on such a contingency for Starliner? There has got to be a plan. Same question goes for Crew Dragon.
When/if there are 2 U.S. visiting vehicles, don't crew store their own specific IVA suits on the vehicle they arrive in? If so, wouldn't each crew member need to bug out to their specific capsule to have best chance for survival?
If they can each use their own vehicle, that's optimal, nobody would argue with that.
But I think the subject under discussion right now is what happens when that's not an option.
If the situation on the station is bad and they need to get off, you can cram everyone into one vehicle. Even if they don't have suits, or even proper seats, they are very likely to survive, which is better than staying on the station to face certain death.
NASA plans for pretty much every conceivable event when it comes to human space flight, and that has certainly been true regarding mission critical events on ISS that require evacuation.
I'm sure they have a plan for evacuating all crew on a Dragon or a Starliner. Since I doubt they have any spare pressure suits (which after all have to be tailored to the astronaut) or extra seats packed away in the capsule(s), I assume they have some improvised means of securing the seatless astronauts/cosmonauts inside the cabin, and they just accept that there's going to be a considerable higher risk on reentry and landing to them. But it would still beat the alternative whatever the risk is.
I know this is a Starliner thread but I need to make a correction to a statement I made upthread regarding the dropping of the crew compliment from 7 to 4 on both Dragon and Starliner. After doing further research I've figured out that at least in the case of Crew Dragon, it wasn't the ISS crew compliment that forced the change, but rather a NASA Specification change to the design of the Dragon interior layout.
In an interview with Stephen Clark for Spaceflight now, Gwen Shotwell addressed the change from 7-crew to 4:
"A requirement change from NASA also contributed to delays [Demo 2]", Shotwell said. "After SpaceX had already designed the interior layout of the Crew Dragon spacecraft, NASA decided to change the specification for the angle of the ship’s seats due to concerns about the g-forces crew members might experience during splashdown. The change meant SpaceX had to do away with the company’s original seven-seat design for the Crew Dragon. With this change and the angle of the seats, we could not get seven anymore,” Shotwell said. “So now we only have four seats. That was kind of a big change for us".
https://spaceflightnow.com/2019/12/07/after-redesigns-the-finish-line-is-in-sight-for-spacexs-crew-dragon/Seven (7) crew are still capable of being crammed in should it ever become necessary to evacuate ISS in a single spacecraft, but it wasn't the ISS crew compliment that forced the downsize - it was a NASA specification change. AFAIK however, the 4-crew on Starliner does conform to the wish to not overburden the ISS with VV crews. But I'm happy to be corrected if that is not the case if someone has better information than mine.
So yes, while both Dragon and Starliner can support 7 crew, both will carry only 4 for ISS missions.
This limit also allows the full station compliment to evacuate in a single spacecraft if necessary.
But neither capsule is equipped with seven seats when flown to the ISS. How would the extra three people be accommodated in such an emergency?
They wouldn't. Despite what clongton thinks, astronauts need to evacuate with their assigned spacecraft. Being able to theoretically stuff in more people is NOT why 7 crew was originally proposed, and it certainly was never a requirement with 2 docked Soyuz. (that more people would squeeze in)
They wouldn't. Despite what clongton thinks, astronauts need to evacuate with their assigned spacecraft. Being able to theoretically stuff in more people is NOT why 7 crew was originally proposed, and it certainly was never a requirement with 2 docked Soyuz. (that more people would squeeze in)
Lars, you are assuming that both spacecraft are available for evacuation, which was *not* the potential being discussed. It was if ISS evacuation is necessary but only 1 spacecraft is available to support that. The assumption was that Soyuz would not be available and only Dragon or Starliner was available. Perhaps it was damaged in whatever event mandated the evacuation, or can no longer be boarded for some reason. In that case either Dragon or Starliner, while having only 4 seats, *could* carry all 7 personnel in an emergency evacuation requirement; very uncomfortable, but either one could do that.
They wouldn't. Despite what clongton thinks, astronauts need to evacuate with their assigned spacecraft. Being able to theoretically stuff in more people is NOT why 7 crew was originally proposed, and it certainly was never a requirement with 2 docked Soyuz. (that more people would squeeze in)
Lars, you are assuming that both spacecraft are available for evacuation, which was *not* the potential being discussed. It was if ISS evacuation is necessary but only 1 spacecraft is available to support that. The assumption was that Soyuz would not be available and only Dragon or Starliner was available. Perhaps it was damaged in whatever event mandated the evacuation, or can no longer be boarded for some reason. In that case either Dragon or Starliner, while having only 4 seats, *could* carry all 7 personnel in an emergency evacuation requirement; very uncomfortable, but either one could do that.
I doubt you will experience 3+G without seats and live to tell the tale.
They wouldn't. Despite what clongton thinks, astronauts need to evacuate with their assigned spacecraft. Being able to theoretically stuff in more people is NOT why 7 crew was originally proposed, and it certainly was never a requirement with 2 docked Soyuz. (that more people would squeeze in)
Lars, you are assuming that both spacecraft are available for evacuation, which was *not* the potential being discussed. It was if ISS evacuation is necessary but only 1 spacecraft is available to support that. The assumption was that Soyuz would not be available and only Dragon or Starliner was available. Perhaps it was damaged in whatever event mandated the evacuation, or can no longer be boarded for some reason. In that case either Dragon or Starliner, while having only 4 seats, *could* carry all 7 personnel in an emergency evacuation requirement; very uncomfortable, but either one could do that.
Of course one can imagine up weird scenarios for the end of the world, but it is not a standard plan. What you are doing just speculation, and the same level of speculation that people were doing about using Cargo Dragon for emergency crew return... "yeah I know it is unlikely, but what if they reaaaaaally had to?". That's what you are doing, and it makes just as little sense as that.
They wouldn't. Despite what clongton thinks, astronauts need to evacuate with their assigned spacecraft. Being able to theoretically stuff in more people is NOT why 7 crew was originally proposed, and it certainly was never a requirement with 2 docked Soyuz. (that more people would squeeze in)
Lars, you are assuming that both spacecraft are available for evacuation, which was *not* the potential being discussed. It was if ISS evacuation is necessary but only 1 spacecraft is available to support that. The assumption was that Soyuz would not be available and only Dragon or Starliner was available. Perhaps it was damaged in whatever event mandated the evacuation, or can no longer be boarded for some reason. In that case either Dragon or Starliner, while having only 4 seats, *could* carry all 7 personnel in an emergency evacuation requirement; very uncomfortable, but either one could do that.
I doubt you will experience 3+G without seats and live to tell the tale.
3g for a few minutes isn't going to kill a typical healthy adult lying on a floor any more than it's going to kill someone in a seat. The orientation of the body is the most important thing. You want to have the force perpendicular to the spine instead of parallel to it to keep the blood from pooling in the feet or head. A seat isn't needed for that. It just makes it more comfortable.
I doubt you will experience 3+G without seats and live to tell the tale.
Nonsense. It won't be reentry deceleration that causes injury, it would be the dynamic environment tossing unrestrained people about, especially when chutes open and at landing.
Personally, I've experienced 2.5 G for a couple minutes at a time without seats multiple times, starting at a fairly young age. Sadly, Worlds of Fun in Kansas City retired the Finnish Fling a couple years ago, so nobody else can do it where I did anymore, but I assure you, I am quite alive.
I doubt you will experience 3+G without seats and live to tell the tale.
Nonsense. It won't be reentry deceleration that causes injury, it would be the dynamic environment tossing unrestrained people about, especially when chutes open and at landing.
Maybe they should keep some big rolls of bubble wrap on the station, in case of emergency. Totally not because it would be fun to have bubble wrap. Just for emergencies, I swear.
Then again, I always thought Securefoam, from the movie Demolition Man was a brilliant idea.
"yeah I know it is unlikely, but what if they reaaaaaally had to?". That's what you are doing, and it makes just as little sense as that.
This seems wrong to me. Yes, it's extremely unlikely. But losing all hydraulic systems on a commercial plane is unlikely, but
there are procedures for that. It would not be worth putting a lot of effort into, but a few weeks of thinking, while not under time pressure, could help considerably if the option is ever needed. So you cram 7 people in. How long will your consumables last? Will the capsule get too hot, and if so how fast? Can you get rid of the CO
2? If not, that sets a strict time limit for landing. What about exhaled water vapor? Where should you set the center of gravity for navigation? Relatively simple questions, but having them tabulated in advance could help a lot if ever needed.
On a more intuitive level, saying that things may get bad, but surely never bad enough that we will have to do X, is almost an invitation to have to do X. On the other hand, wasting a bunch of time for planning how to do X in an emergency is the best way to ensure you'll never need the plan.
"yeah I know it is unlikely, but what if they reaaaaaally had to?". That's what you are doing, and it makes just as little sense as that.
This seems wrong to me. Yes, it's extremely unlikely. But losing all hydraulic systems on a commercial plane is unlikely, but there are procedures for that. It would not be worth putting a lot of effort into, but a few weeks of thinking, while not under time pressure, could help considerably if the option is ever needed. So you cram 7 people in. How long will your consumables last? Will the capsule get too hot, and if so how fast? Can you get rid of the CO2? If not, that sets a strict time limit for landing. What about exhaled water vapor? Where should you set the center of gravity for navigation? Relatively simple questions, but having them tabulated in advance could help a lot if ever needed.
On a more intuitive level, saying that things may get bad, but surely never bad enough that we will have to do X, is almost an invitation to have to do X. On the other hand, wasting a bunch of time for planning how to do X in an emergency is the best way to ensure you'll never need the plan.
Of course it is theoretically possible. And if something truly ISS-ending armageddon scenario happened it would obviously be better to try it than dying.
MY POINT (and people keep missing it), is that this is not an official escape plan that NASA has demanded that the commercial partners support.
- There is no requirement that a Cargo Dragon needs to support 7 crew on the floor and be able to return them safely. (an oft cited scenario on this forum since Cargo Dragon first flew)
- For the same reason there is also no requirement for being able to pack in 7 people into a Starliner (or Crew Dragon)
that only has 4 seats, 4 custom-fitted IVA suits, and consumables for 4.Because the moment such requirements appear, the mountain of paperwork and costs would be immense, and the cost of the vehicles would go up. (and be delayed)
Think of it as packing in 10 people in a car that seats 5. Technically possible? Yeah. Safe or advisable? No way. Do you see any car manufacturer stating that 'in a pinch you can fit 10 people in this car'. Never.
"yeah I know it is unlikely, but what if they reaaaaaally had to?". That's what you are doing, and it makes just as little sense as that.
This seems wrong to me. Yes, it's extremely unlikely. But losing all hydraulic systems on a commercial plane is unlikely, but there are procedures for that. It would not be worth putting a lot of effort into, but a few weeks of thinking, while not under time pressure, could help considerably if the option is ever needed. So you cram 7 people in. How long will your consumables last? Will the capsule get too hot, and if so how fast? Can you get rid of the CO2? If not, that sets a strict time limit for landing. What about exhaled water vapor? Where should you set the center of gravity for navigation? Relatively simple questions, but having them tabulated in advance could help a lot if ever needed.
On a more intuitive level, saying that things may get bad, but surely never bad enough that we will have to do X, is almost an invitation to have to do X. On the other hand, wasting a bunch of time for planning how to do X in an emergency is the best way to ensure you'll never need the plan.
Of course it is theoretically possible. And if something truly ISS-ending armageddon scenario happened it would obviously be better to try it than dying.
MY POINT (and people keep missing it), is that this is not an official escape plan that NASA has demanded that the commercial partners support.
- There is no requirement that a Cargo Dragon needs to support 7 crew on the floor and be able to return them safely. (an oft cited scenario on this forum since Cargo Dragon first flew)
- For the same reason there is also no requirement for being able to pack in 7 people into a Starliner (or Crew Dragon) that only has 4 seats, 4 custom-fitted IVA suits, and consumables for 4.
Because the moment such requirements appear, the mountain of paperwork and costs would be immense, and the cost of the vehicles would go up. (and be delayed)
Think of it as packing in 10 people in a car that seats 5. Technically possible? Yeah. Safe or advisable? No way. Do you see any car manufacturer stating that 'in a pinch you can fit 10 people in this car'. Never.
Sure. I'm not aware of it as a contract requirement, either.
And yet, we know that when it comes to HSF, NSA has a contingency plan for virtually any eventuality, however unlikely. That's how it has been since the days of Mercury.
So I could readily see NASA approaching Boeing and SpaceX and saying, "We're not making this a formal requirement, but we'd like to come together, unofficially, to see what we can work up for scenarios where it is necessary to evacuate and return to Earth additional personnel beyond the four who travelled up as crew in the capsule." That could be as simple as minimal equipment to secure and cushion the additional astronauts to the capsule floor and perhaps a small personal oxygen mask against depressurization; maybe it could even involve a contingency reentry profile with slightly lower g-loads - all with the understanding that the risk levels to those personnel are going to be significantly higher (which still beats certain death, obviously). Not something huge amounts of resources or paperwork would be expended on. It is, after all, a very unlikely scenario.
An oxygen mask won't save you if depressurization occurs. Just send up an unmanned craft to replace their disabled craft. It's simple.