Author Topic: Commercial Crew LOM scenario  (Read 6361 times)

Offline rayleighscatter

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Commercial Crew LOM scenario
« on: 05/13/2017 09:26 PM »
What happens in the event of a loss of mission (not loss of crew) in regards to the commercial crew and ISS programs? (Think: inflight abort)

I got to thinking about this because LOM will likely have a much bigger impact on the ISS than it would in the crew program. The crew on station would presumably be approaching the end of the on-orbit life of their vehicle within a few weeks/months. So either a new crew mission has to launch on short notice or a new "life boat" has to be sent up to ISS.

Would the provider that faced the LOM have to turn around quickly and attempt a new mission? With no saying of a possible stand down to investigate/repair whatever caused the LOM.

Would the alternate provider have to move their next scheduled mission to the left 5-6 months?

It seems like a bit of a conundrum because there is consideration of the crew on ISS and their return ship. The commercial crew program would have to provide an alternate flight in some form within maybe 2 months. And the CC providers might have to accelerate their own schedules to maintain proper rotation cadence (of both crew and craft) at the ISS which might have one provider finding themselves with an accelerated mission as well as an unexpected followup 6 months later (and maybe a third...) as the other provider completes return to flight.

Or would everything just fall back on Soyuz again?


Offline Proponent

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Re: Commercial Crew LOM scenario
« Reply #1 on: 05/14/2017 02:05 AM »
Or would everything just fall back on Soyuz again?

[joke]
No, because, by federal law, Orion/SLS has been available as a back-up ISS transport system since 31 December 2016.
[/joke]

Offline woods170

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Re: Commercial Crew LOM scenario
« Reply #2 on: 05/14/2017 11:19 AM »
What happens in the event of a loss of mission (not loss of crew) in regards to the commercial crew and ISS programs? (Think: inflight abort)

I got to thinking about this because LOM will likely have a much bigger impact on the ISS than it would in the crew program. The crew on station would presumably be approaching the end of the on-orbit life of their vehicle within a few weeks/months. So either a new crew mission has to launch on short notice or a new "life boat" has to be sent up to ISS.

Would the provider that faced the LOM have to turn around quickly and attempt a new mission? With no saying of a possible stand down to investigate/repair whatever caused the LOM.

Would the alternate provider have to move their next scheduled mission to the left 5-6 months?

It seems like a bit of a conundrum because there is consideration of the crew on ISS and their return ship. The commercial crew program would have to provide an alternate flight in some form within maybe 2 months. And the CC providers might have to accelerate their own schedules to maintain proper rotation cadence (of both crew and craft) at the ISS which might have one provider finding themselves with an accelerated mission as well as an unexpected followup 6 months later (and maybe a third...) as the other provider completes return to flight.

Or would everything just fall back on Soyuz again?


You already gave the answer. Why do you think NASA has TWO commercial crew providers? They are each others back-ups in case one of them has a bad day.

Offline rayleighscatter

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Re: Commercial Crew LOM scenario
« Reply #3 on: 05/14/2017 02:09 PM »
What happens in the event of a loss of mission (not loss of crew) in regards to the commercial crew and ISS programs? (Think: inflight abort)

I got to thinking about this because LOM will likely have a much bigger impact on the ISS than it would in the crew program. The crew on station would presumably be approaching the end of the on-orbit life of their vehicle within a few weeks/months. So either a new crew mission has to launch on short notice or a new "life boat" has to be sent up to ISS.

Would the provider that faced the LOM have to turn around quickly and attempt a new mission? With no saying of a possible stand down to investigate/repair whatever caused the LOM.

Would the alternate provider have to move their next scheduled mission to the left 5-6 months?

It seems like a bit of a conundrum because there is consideration of the crew on ISS and their return ship. The commercial crew program would have to provide an alternate flight in some form within maybe 2 months. And the CC providers might have to accelerate their own schedules to maintain proper rotation cadence (of both crew and craft) at the ISS which might have one provider finding themselves with an accelerated mission as well as an unexpected followup 6 months later (and maybe a third...) as the other provider completes return to flight.

Or would everything just fall back on Soyuz again?


You already gave the answer. Why do you think NASA has TWO commercial crew providers? They are each others back-ups in case one of them has a bad day.

So NASA will encourage (and pay) for the providers to build up a stock of stored LVs? This would also assume that the program can do launch on demand to move flights many months forward. At least at this point flights are being ordered with about 2 years lead time.

Offline pathfinder_01

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Re: Commercial Crew LOM scenario
« Reply #4 on: 05/14/2017 02:23 PM »
What happens in the event of a loss of mission (not loss of crew) in regards to the commercial crew and ISS programs? (Think: inflight abort)

I got to thinking about this because LOM will likely have a much bigger impact on the ISS than it would in the crew program. The crew on station would presumably be approaching the end of the on-orbit life of their vehicle within a few weeks/months. So either a new crew mission has to launch on short notice or a new "life boat" has to be sent up to ISS.

Would the provider that faced the LOM have to turn around quickly and attempt a new mission? With no saying of a possible stand down to investigate/repair whatever caused the LOM.

Would the alternate provider have to move their next scheduled mission to the left 5-6 months?

It seems like a bit of a conundrum because there is consideration of the crew on ISS and their return ship. The commercial crew program would have to provide an alternate flight in some form within maybe 2 months. And the CC providers might have to accelerate their own schedules to maintain proper rotation cadence (of both crew and craft) at the ISS which might have one provider finding themselves with an accelerated mission as well as an unexpected followup 6 months later (and maybe a third...) as the other provider completes return to flight.

Or would everything just fall back on Soyuz again?


You already gave the answer. Why do you think NASA has TWO commercial crew providers? They are each others back-ups in case one of them has a bad day.

So NASA will encourage (and pay) for the providers to build up a stock of stored LVs? This would also assume that the program can do launch on demand to move flights many months forward. At least at this point flights are being ordered with about 2 years lead time.

Well Space X seems to be doing a fine job of building up stored LV and ULA has the launch on demand program and thus is keeping an extra Atlas around.....

The way you would do it is as follows. Most ISS crew only stay three months on the ISS. CC requires that vechiles have a 6 month life at the station. CST-100 was planning 7 months. Dragon 2 is planning 2 years. The lom would occur 3 months in. The other provider would be asked to move up it's prescheduled flight.

The ideal way to schedule missions would be to alternate providers so that if one has problems you can use the next. i.e. CST-100 would have 1 mission and the next would be flown by Space X three months later.

Offline rayleighscatter

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Re: Commercial Crew LOM scenario
« Reply #5 on: 05/14/2017 02:49 PM »
What happens in the event of a loss of mission (not loss of crew) in regards to the commercial crew and ISS programs? (Think: inflight abort)

I got to thinking about this because LOM will likely have a much bigger impact on the ISS than it would in the crew program. The crew on station would presumably be approaching the end of the on-orbit life of their vehicle within a few weeks/months. So either a new crew mission has to launch on short notice or a new "life boat" has to be sent up to ISS.

Would the provider that faced the LOM have to turn around quickly and attempt a new mission? With no saying of a possible stand down to investigate/repair whatever caused the LOM.

Would the alternate provider have to move their next scheduled mission to the left 5-6 months?

It seems like a bit of a conundrum because there is consideration of the crew on ISS and their return ship. The commercial crew program would have to provide an alternate flight in some form within maybe 2 months. And the CC providers might have to accelerate their own schedules to maintain proper rotation cadence (of both crew and craft) at the ISS which might have one provider finding themselves with an accelerated mission as well as an unexpected followup 6 months later (and maybe a third...) as the other provider completes return to flight.

Or would everything just fall back on Soyuz again?


You already gave the answer. Why do you think NASA has TWO commercial crew providers? They are each others back-ups in case one of them has a bad day.

So NASA will encourage (and pay) for the providers to build up a stock of stored LVs? This would also assume that the program can do launch on demand to move flights many months forward. At least at this point flights are being ordered with about 2 years lead time.


The way you would do it is as follows. Most ISS crew only stay three months on the ISS. CC requires that vechiles have a 6 month life at the station.
Most crews stay 170-190 days and the on-orbit requirement for commercial crew vehicles is 210 days.

That means after a failure there's ideally just over 3 months of on-orbit life left for the vehicle at the station.

ULA's rapidlaunch program advertises "as little as 3 months." This presumably means additional requirements, such as those for a manned launch, would increase this period of time. And as best as I'm aware, SpaceX can't offer reused boosters for commercial crew.

And as recent return to flight operations recently have taken more than 6 months how does this affect the situation as the alternate provider would be moving up their flight they are preparing and would have to have a brand new flight ready within 6 months, and possibly another 6 months after that. So a provider that was preparing for a single flight in the following 12 month period would then be preparing for 3 launches in that same period. Is that kind of production and support possible on both the crew vehicle and LV sides, and from both providers?


Offline pathfinder_01

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Re: Commercial Crew LOM scenario
« Reply #6 on: 05/14/2017 03:00 PM »
Which is why you alternate. Space X would go first...have a lom. ULA would go next. As for the average it is being driven up by that one year stay. 

Offline JazzFan

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Re: Commercial Crew LOM scenario
« Reply #7 on: 05/14/2017 04:19 PM »
Both ULA and SpaceX have good process flows for the launch vehicles but I don't see them as having a stockpile of crew modules as a contingency for LOM, especially if they are not getting paid for that function.  My question would be how long it would take to accelerate production on a single source to prevent an interruption in the manned launch schedule.

Offline Lars-J

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Re: Commercial Crew LOM scenario
« Reply #8 on: 05/14/2017 04:31 PM »
Both ULA and SpaceX have good process flows for the launch vehicles but I don't see them as having a stockpile of crew modules as a contingency for LOM, especially if they are not getting paid for that function.  My question would be how long it would take to accelerate production on a single source to prevent an interruption in the manned launch schedule.

I don't see the big problem. SpaceX has switched around launch dates for missions before. Cores have been reassigned. ULA has done the same, I'm sure.

I would not be surprised if the commercial crew contracts involved some kind of priority clause that allowed them to jump the line if necessary.

Offline rayleighscatter

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Re: Commercial Crew LOM scenario
« Reply #9 on: 05/14/2017 07:07 PM »
Which is why you alternate. Space X would go first...have a lom. ULA would go next. As for the average it is being driven up by that one year stay.
Just from looking at the most recent Soyuz missions duration:
Soyuz MS02- 173 days
Soyuz MS01- 115 days
Soyuz TMA20M- 172 days
Soyuz TMA19M- 185 days
Soyuz TMA18M- 179 days
Soyuz TMA17M -141 days
Soyuz TMA16M- 167 days
Soyuz TMA15M- 199 days
Soyuz TMA14M- 166 days
Soyuz TMA13M- 165 days
Soyuz TMA12M- 169 days
Soyuz TMA11M-187 days
etc.

Offline deruch

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Re: Commercial Crew LOM scenario
« Reply #10 on: 05/14/2017 09:43 PM »
Both ULA and SpaceX have good process flows for the launch vehicles but I don't see them as having a stockpile of crew modules as a contingency for LOM, especially if they are not getting paid for that function.  My question would be how long it would take to accelerate production on a single source to prevent an interruption in the manned launch schedule.
Both providers are also working on making their capsules reusable, so it may be that there isn't such a problem on the spacecraft side.  Though SpaceX's original plan in this direction is currently somewhat hampered by NASA's requiring them to switch to water landings to begin with.  They may be forced to wait for powered "land"-landings to be approved before they can offer a fast response launch.
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline Augustus_

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Re: Commercial Crew LOM scenario
« Reply #11 on: 05/14/2017 09:58 PM »
And as best as I'm aware, SpaceX can't offer reused boosters for commercial crew.

But if it was an emergency, couldn't they????

Offline rayleighscatter

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Re: Commercial Crew LOM scenario
« Reply #12 on: 05/14/2017 10:56 PM »
And as best as I'm aware, SpaceX can't offer reused boosters for commercial crew.

But if it was an emergency, couldn't they????
Would NASA want to slacken a set of safety rules so soon after a major public incident?
It's one of the things often brought up when it's asked if a Columbia rescue could have been made. Even if it had been technically feasible, would anyone have given the go ahead for Atlantis to go up and potentially also face the same accident. Basically would doing thing #2 unsafely to fix unsafe thing #1 be appropriate? I'm not sure I've ever heard a definitive answer on that.


It also wouldn't be a case of life or death afterall. The crew on station could still return in their capsule up until 210 days. It would just leave station manned only by the Russians.
« Last Edit: 05/14/2017 11:00 PM by rayleighscatter »

Online abaddon

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Re: Commercial Crew LOM scenario
« Reply #13 on: 05/15/2017 03:14 AM »
Unlike Shuttle, Dragon and Starliner can go up fully autonomously... I guess that doesn't solve a crew rotation problem, but it does highlight that Shuttle isn't a good comp here.
« Last Edit: 05/15/2017 06:46 PM by abaddon »

Offline woods170

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Re: Commercial Crew LOM scenario
« Reply #14 on: 05/15/2017 06:25 AM »
What happens in the event of a loss of mission (not loss of crew) in regards to the commercial crew and ISS programs? (Think: inflight abort)

I got to thinking about this because LOM will likely have a much bigger impact on the ISS than it would in the crew program. The crew on station would presumably be approaching the end of the on-orbit life of their vehicle within a few weeks/months. So either a new crew mission has to launch on short notice or a new "life boat" has to be sent up to ISS.

Would the provider that faced the LOM have to turn around quickly and attempt a new mission? With no saying of a possible stand down to investigate/repair whatever caused the LOM.

Would the alternate provider have to move their next scheduled mission to the left 5-6 months?

It seems like a bit of a conundrum because there is consideration of the crew on ISS and their return ship. The commercial crew program would have to provide an alternate flight in some form within maybe 2 months. And the CC providers might have to accelerate their own schedules to maintain proper rotation cadence (of both crew and craft) at the ISS which might have one provider finding themselves with an accelerated mission as well as an unexpected followup 6 months later (and maybe a third...) as the other provider completes return to flight.

Or would everything just fall back on Soyuz again?


Apart from the point I already noted earlier (there is TWO CCP providers for a reason) it is also a fact that there will always be also a Soyuz present at the station AND the station is still perfectly safe even if just manned by a two-person crew for several months. The reason is the halfway swap of Expedition crew members. That is there for a reason. CCP becoming operational will not change that all that much. So, even if a CCP suffers a LOM, there will be no need to de-crew ISS. It will just continue with half a crew until the next CCP flight goes up. And subsequent CCP and Soyuz flight after that can be accelerated to get back into the schedule of halfway crew swaps.

Online A_M_Swallow

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Re: Commercial Crew LOM scenario
« Reply #15 on: 05/15/2017 12:44 PM »
Apart from the point I already noted earlier (there is TWO CCP providers for a reason) it is also a fact that there will always be also a Soyuz present at the station AND the station is still perfectly safe even if just manned by a two-person crew for several months. The reason is the halfway swap of Expedition crew members. That is there for a reason. CCP becoming operational will not change that all that much. So, even if a CCP suffers a LOM, there will be no need to de-crew ISS. It will just continue with half a crew until the next CCP flight goes up. And subsequent CCP and Soyuz flight after that can be accelerated to get back into the schedule of halfway crew swaps.

A CCP suffering a LOM may not be able to reenter. A hull breach or damage to its heat shield may prevent reentry. A damaged docking port may prevent docking. A hull breach where the docking port connects to the main airframe could prevent both reentry and docking. Mission Control's problem is now how to rescue the crew.

Offline WindnWar

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Re: Commercial Crew LOM scenario
« Reply #16 on: 05/15/2017 01:15 PM »
Apart from the point I already noted earlier (there is TWO CCP providers for a reason) it is also a fact that there will always be also a Soyuz present at the station AND the station is still perfectly safe even if just manned by a two-person crew for several months. The reason is the halfway swap of Expedition crew members. That is there for a reason. CCP becoming operational will not change that all that much. So, even if a CCP suffers a LOM, there will be no need to de-crew ISS. It will just continue with half a crew until the next CCP flight goes up. And subsequent CCP and Soyuz flight after that can be accelerated to get back into the schedule of halfway crew swaps.

A CCP suffering a LOM may not be able to reenter. A hull breach or damage to its heat shield may prevent reentry. A damaged docking port may prevent docking. A hull breach where the docking port connects to the main airframe could prevent both reentry and docking. Mission Control's problem is now how to rescue the crew.

I see very few ways that could happen that would not result in a loss of crew. Dragon has a trunk between it and the second stage. Damage to the docking that breaches the hull isn't possible unless you say collide with the space station. Damage to the heat shield would require a second stage to explode, likely damaging it at a low enough altitude that it would not be able to stay in orbit and might destroy the fuel tanks for maneuvering. Pretty much the same scenarios for CST-100.

If you hit the space station you have plenty of issues to deal with, and it would depend on whether the flight suits can be used in anyway to transfer the crew to the station via eva and say the station arm. I have no idea on that.

Anything able to do catastrophic damage to the heat shield probably kills the crew outright or dooms them before they could reach a stable orbit. The likelihood of either is probably incredibly low.

Offline smfarmer11

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Re: Commercial Crew LOM scenario
« Reply #17 on: 05/15/2017 01:49 PM »
Such damage could occur as a result of an MMOD strike hitting near the docking adapter.

Offline Augustus_

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Re: Commercial Crew LOM scenario
« Reply #18 on: 05/15/2017 05:09 PM »
Unlike Shuttle, Dragon and Starliner can go up fully autonomously... I guess that doesn't solve a crew rotation problem, but it does highlight that Shuttle isn't good comp here.

Exactly. You could send up an automated Dragon 2 on a refurbished booster.

Offline woods170

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Re: Commercial Crew LOM scenario
« Reply #19 on: 05/15/2017 05:15 PM »
Such damage could occur as a result of an MMOD strike hitting near the docking adapter.
Yes and an MMOD strike can hit any spacecraft. Not just the CCP providers.

Online A_M_Swallow

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Re: Commercial Crew LOM scenario
« Reply #20 on: 05/15/2017 11:31 PM »
Such damage could occur as a result of an MMOD strike hitting near the docking adapter.
Yes and an MMOD strike can hit any spacecraft. Not just the CCP providers.

True but this is a Commercial Crew thread. Orion is NASA's problem. Each CCP provider needs a solution for its own spacecraft.

Offline docmordrid

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Re: Commercial Crew LOM scenario
« Reply #21 on: 05/16/2017 05:14 AM »
ISTM there is no full solution, only mitigations, and those mitigations (Whipple shields etc.) are pretty well understood.
« Last Edit: 05/16/2017 05:16 AM by docmordrid »
DM

Offline woods170

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Re: Commercial Crew LOM scenario
« Reply #22 on: 05/16/2017 08:44 AM »
Such damage could occur as a result of an MMOD strike hitting near the docking adapter.
Yes and an MMOD strike can hit any spacecraft. Not just the CCP providers.

True but this is a Commercial Crew thread. Orion is NASA's problem. Each CCP provider needs a solution for its own spacecraft.
It is slightly more subtle than that. CCP requirements, issued by NASA btw, also include requirements for MMOD protection.

Offline Hog

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Re: Commercial Crew LOM scenario
« Reply #23 on: 05/22/2017 08:22 PM »
Unlike Shuttle, Dragon and Starliner can go up fully autonomously... I guess that doesn't solve a crew rotation problem, but it does highlight that Shuttle isn't a good comp here.
Are you meaning that Shuttle couldn't launch to ISS without a crew?  Shuttle could launch with its normal flight crew compliment of 4, and still pick up a full ISS crew for de orbit.  Of course it wouldn't be doing the on station stay of 180 days.
Perhaps I am comprehending this poorly?
Paul

Offline ValmirGP

Re: Commercial Crew LOM scenario
« Reply #24 on: 05/22/2017 08:38 PM »
If I recall correctly, Columbia flew with a two crew only on its debut mission.

Offline woods170

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Re: Commercial Crew LOM scenario
« Reply #25 on: 05/22/2017 08:55 PM »
If I recall correctly, Columbia flew with a two crew only on its debut mission.
That was the minimum required. Very much later in the program it became possible to re-enter and land an orbiter unmanned. But, launching it unmanned and have it dock with the ISS unmanned, was never in the realm of possibilities.

Offline Hog

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Re: Commercial Crew LOM scenario
« Reply #26 on: 05/27/2017 11:27 AM »
If I recall correctly, Columbia flew with a two crew only on its debut mission.
Correct, the 4 test missions, STS-1 through STS-4 were conducted with a crew of 2.

I stated a crew of four as that's what the Columbia Accident Investigation Board (CAIB) stated as the launch crew size would have been aboard Atlantis for the rescue.  Commander, Pilot and a couple EVA crew. In January, seven commanders, seven pilots, and nine spacewalk-trained astronauts were available. Downmass would have been 11 souls, 4 on the flight deck, and 7 on the middeck, if the rescue option would have been exercised.
Paul

Re: Commercial Crew LOM scenario
« Reply #27 on: 05/30/2017 09:13 PM »
http://spacenews.com/commercial-crew-vehicles-may-fall-short-of-safety-threshold/

Commercial crew vehicles may fall short of safety threshold

Quote
“The number one safety-related concern for the program is the current situation with respect to the estimate of loss of crew,” Donald McErlean, a former engineering fellow at L-3 Communications and a member of the panel, said at the meeting. “The threshold values were considered to be challenging, and both contractors currently have a challenge to meet that precise number.”

Quote
If either or both companies can’t meet the LOC requirement with the spacecraft, NASA may have to issue waivers for that requirement. “That remains a risk to the program that will have to be addressed, in all likelihood, by a risk acceptance waiver,” McErlean said.

“It may be necessary to do a formal risk acceptance of the variance from the stipulated goal,” he said later in the meeting. “We would remind NASA that that risk acceptance, including a complete presentation of the alternatives and the consequences, should be made formally, and that risk acceptance signed off by appropriate authorities.”






Offline woods170

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Re: Commercial Crew LOM scenario
« Reply #28 on: 05/31/2017 06:57 AM »
From the same article these important take-aways:

http://spacenews.com/commercial-crew-vehicles-may-fall-short-of-safety-threshold/

Quote from: Jeff Foust
He (Donald McErlean, a former engineering fellow at L-3 Communications and a member of the ASAP panel) also warned against placing too much emphasis on the LOC metric alone. “One has to be judicious in how one applies these statistical estimates,” he said. “One has to look at whether or not the contractors have expended the necessary effort and engineering activity to make the system as safe as they conceivably can and still perform the mission.”

He added that he was ”very positive” both companies were doing so. “There was no known or indicated area where with, by spending even a small amount of money, the contractor could have made their systems considerably safer.”

Bill Gerstenmaier, NASA associate administrator for human exploration and operations, has also warned against focusing too much on the LOC statistic alone in weighing risks of flying crewed spacecraft.

Offline ChrisGebhardt

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Re: Commercial Crew LOM scenario
« Reply #29 on: 05/31/2017 04:08 PM »
From the same article these important take-aways:

http://spacenews.com/commercial-crew-vehicles-may-fall-short-of-safety-threshold/

Quote from: Jeff Foust
He (Donald McErlean, a former engineering fellow at L-3 Communications and a member of the ASAP panel) also warned against placing too much emphasis on the LOC metric alone. “One has to be judicious in how one applies these statistical estimates,” he said. “One has to look at whether or not the contractors have expended the necessary effort and engineering activity to make the system as safe as they conceivably can and still perform the mission.”

He added that he was ”very positive” both companies were doing so. “There was no known or indicated area where with, by spending even a small amount of money, the contractor could have made their systems considerably safer.”

Bill Gerstenmaier, NASA associate administrator for human exploration and operations, has also warned against focusing too much on the LOC statistic alone in weighing risks of flying crewed spacecraft.

And Kathy Lueders said the same thing this morning at the CCP Q&A media event.  Final LOC estimates for Dragon and Starliner might not match the 1-in-270 benchmark at the outset, but she's happy with where both companies are.

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