Author Topic: ASAP still has concerns over Commercial Crew LOC risks  (Read 39434 times)

Online Chris Bergin

It's your friendly ASAP sticking their nose in again :)

Interesting, all the same. Used some Nathan L2 renders, of course, to make the article sexier.

https://www.nasaspaceflight.com/2017/08/asap-concerns-commercial-crew-loc-risks/

Pardon me if this has already been discussed. However,  I would be interested to know how Soyuz scores based on the same criteria.

Offline whitelancer64

Pardon me if this has already been discussed. However,  I would be interested to know how Soyuz scores based on the same criteria.

I found a brief mention in the 2005 ESAS

https://www.nasa.gov/pdf/140639main_ESAS_08.pdf

Which gives the Soyuz LOC risk as 0.3%, or 1 in 333, and 0.5%, or 1 in 200, but these numbers are in a comparative chart, it does not explain how they arrived at the risk numbers.
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Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #3 on: 08/23/2017 06:50 PM »
It's your friendly ASAP sticking their nose in again :)

Interesting, all the same. Used some Nathan L2 renders, of course, to make the article sexier.

https://www.nasaspaceflight.com/2017/08/asap-concerns-commercial-crew-loc-risks/
Well I have to admit: they are consistent...


...in being boring as h*ll.

It's the same old tune being played over-and-over-and-over again.

Offline jkumpire

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #4 on: 08/23/2017 07:08 PM »
If these guys were around when Mercury was constructed and launched we wouldn't  be in space yet, or at best flying the 1035th M/R mission while the Atlas-E or Atlas V or Atlas QQ would be working on their 5000th qualification flight. NASA would be out of test monkeys, dogs, cats, gators, snakes, and raccoons.

 

Offline Coastal Ron

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #5 on: 08/23/2017 07:31 PM »
From the article, and just so we more directly discuss/debate the issues:
Quote
The ASAP was presented with the three main “programmatic and safety risks” currently challenging the CCP, noted as the:

A. “inability to meet Loss of Crew (LOC) metrics
B. DoD’s Search and Rescue posture and capability
C. the possibility of aborts taking place in sea states that would be unsafe for rescue.”


It would seem to me that "B & C" might be easier to quantify and address, although both are contingent on weather and sea conditions that could change from moment to moment, which would be unpredictable.

For "A", in the article it says:
Quote
That was acknowledged by another ASAP panel member, who noted “One of the things the Panel has begun to observe and discuss is the considerable statistical distribution between the probabilities that are used in the model. As an example, one of the current calculations uses a value of 1:300 as a calculation for overall risk, but statistically, that number can vary between 1:140 and 1:1200.

This seems to be the biggest unresolved issue, is how this portion of risk is both quantified and calculated. Whereas "B & C" could be solved by training and launch timing, "A" seems to be directly related to spacecraft design and how well they can handle collisions and damage.

And at this point in the Commercial Crew program I would imagine it's too late to start adding layers of additional protection, like armor or active protection systems, so I would imagine that ASAP will end up stating that they are not happy about the levels of protection, but that they won't make too big of a fuss about it. And while we all want to have safe space transportation systems, risk has to be assumed - as it should be for any transportation system that is still, even after 50 years, in it's early days of maturity.
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Offline duh

Are there numerical breakouts of how much of the risk is associated with each of the areas of concern?
For instance, what is the risk of MMOD causing LOC? or the sea state being unacceptable?

Pie in the sky (pun intended!) idea: Fly an extra Dragon unmanned as an on-orbit spare AND also
have an extra Dragon (or Starliner, or whatever) available on the ground for an rapid emergency
response, If the is MMOD damage, the assumption (hopefully valid) is that inspection on orbit would
preclude using a damaged spacecraft.

Another possibility would be to launch with maximum crew size of 3 but under emergency conditions
provide a means to reconfigure a second spacecraft to carry 6 people.

As for the sea state concern during ascent, how much more difficult would this be than having the
need to a trans-atlantic abort site during the shuttle era? Rephrasing the point, how much would be
probability of meeting launch commit criteria be lowered if the sea state was added to the rather
large list of constraints that already exists.

Just a thought or two to encourage discussion

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #7 on: 08/23/2017 08:15 PM »

As for the sea state concern during ascent, how much more difficult would this be than having the
need to a trans-atlantic abort site during the shuttle era?

A TAL site has only a few people, a ship in the Atlantic has many times more


 Rephrasing the point, how much would be
probability of meeting launch commit criteria be lowered if the sea state was added to the rather
large list of constraints that already exists.


It already is for the barge and it was also for other manned capsule missions.

Offline john smith 19

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #8 on: 08/23/2017 09:38 PM »

As for the sea state concern during ascent, how much more difficult would this be than having the
need to a trans-atlantic abort site during the shuttle era?

A TAL site has only a few people, a ship in the Atlantic has many times more


 Rephrasing the point, how much would be
probability of meeting launch commit criteria be lowered if the sea state was added to the rather
large list of constraints that already exists.


It already is for the barge and it was also for other manned capsule missions.
That appears to be a logical contradiction.  :(

If sea state is already a launch constraint and the launch is scrubbed if it's too bad then the only way this is a LOC/LOM issue is if a)Launch goes ahead (IE Sea State acceptable then b) something goes wrong with booster but c)Sea State has worsened in the time between takeoff and capsule emergency landing.

What is that? 15-30 mins? With satellite surveillance of the whole launch and abort zone?

Am I missing something here? Is the timescale wrong? This only seems a credible scenario if Mission Control has failed to launch at least one time already and the person in charge says "We've got a 30 minute weather window and I'm feeling lucky so let's get this done" and it all goes wrong.   :(

This is a plot for an SF thriller.  :( It's completely non sensical IRL.

NASA would have be to extraordinarily desperate to behave in such a reckless fashion, and if they did safety concerns are pretty much out the window anyway.  :(

I do think its interesting that this is saying that the #1 mission and crew ending risk in LEO is micrometeroid damage.

So given that, what NASA programmes are targeting the reduction of this (some level of which is man made, but I don't know how much) ?

You'd think, given they are saying it could stop a multi $Bn mission in its tracks and/or take the lives of multiple astronauts that would be right at the top of the to-do list, because y'know "the safety of our astronauts is our highest priority."
« Last Edit: 08/23/2017 09:40 PM by john smith 19 »
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #9 on: 08/23/2017 09:53 PM »
Sea state can effect re-entry. Although if the capsule can wait an extra 45 minutes it can fly from the Pacific to the Atlantic.

Offline Brovane

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #10 on: 08/23/2017 09:59 PM »
So what happened to all the "hand-wringing" over SpaceX planning to fuel the F9 while the astronauts are on board?  I am just surprised considering all the back and forth about this proposed practice after the AMOS-6 anomaly that the article makes no mention of it being a current concern for ASAP. 
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Offline john smith 19

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #11 on: 08/23/2017 10:46 PM »
Sea state can effect re-entry. Although if the capsule can wait an extra 45 minutes it can fly from the Pacific to the Atlantic.
But that's not a launch abort scenario.  :(

So

a) the capsule has to separate from the ISS and deorbit without delay and has to land in a non ideal sea state.

Or

b)it's separated already and it's been on orbit awaiting re-entry so long that the sea state has changed, again to a radically worse one.

a) This could be due to a catastrophic failure of the ISS, but if that were true once safety separated there should be enough time to await a safe landing zone. To give you a hard time limit and force a landing in worst case sea state conditions you'd need something like an imminent massive solar storm, forcing near immediate re-entry to have any hope of surviving.

Except by this point you're so far away from standard operating procedures any safety calculations have to be viewed as out the window. :( 

b) Seems even less likely.
AFAIK storm in the primary landing zone --> scrub landing. Again you'd have to have some really compelling (IE Life or death) reason not to stay on station a day or two longer and just sit the storm out.  :(

But this scenario seems to need 2 faults. The primary LZ is OK (so separation from Station is normal) but something fails and the capsule goes to a secondary with bad sea state, because Landing Commit Criteria
(and I'm quite sure NASA has a set) are not as strict as launch commit criteria.

Really?

IIRC Shuttle takeoffs and landings were scrubbed if any of the landing sites had poor weather on them.

IOW so much has to have gone wrong already that the chances of the crew surviving are already seriously reduced anyway.  :(

I would also ask is there in fact any design of capsule that can survive the stated sea states they are concerned about? IOW are they saying they don't like any capsule, or just the way these have been designed?

This ASAP complaint. It doesn't seem to make sense, but I'm not sure why.  :(
« Last Edit: 08/23/2017 10:57 PM by john smith 19 »
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Offline Hauerg

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #12 on: 08/23/2017 11:12 PM »
Pardon me if this has already been discussed. However,  I would be interested to know how Soyuz scores based on the same criteria.

I found a brief mention in the 2005 ESAS

https://www.nasa.gov/pdf/140639main_ESAS_08.pdf

Which gives the Soyuz LOC risk as 0.3%, or 1 in 333, and 0.5%, or 1 in 200, but these numbers are in a comparative chart, it does not explain how they arrived at the risk numbers.
No idea: But STS had 1 in 50, so 2%. Seems NASA wS OK with that.

Offline Coastal Ron

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #13 on: 08/23/2017 11:42 PM »
So what happened to all the "hand-wringing" over SpaceX planning to fuel the F9 while the astronauts are on board?  I am just surprised considering all the back and forth about this proposed practice after the AMOS-6 anomaly that the article makes no mention of it being a current concern for ASAP.

I'm not sure we can assume it's still not a concern for NASA, but yeah, no mention by the ASAP is sure interesting.

Maybe we won't get positive confirmation about this topic until NASA is done with their review of Block 5? And can we assume that SpaceX is still planning to load crew first and fuel second? Or is it possible that SpaceX decided to do-it-how-it's-always-been-done and fuel first and load crew second?

Inquiring minds want to know!
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Offline UltraViolet9

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #14 on: 08/24/2017 12:28 AM »

A little off topic, but related...

Was there any ASAP discussion about the 1-in-75 LOC for SLS/Orion?

Relative to CC 1-in-270 LOC goal and 1-in-150 LOC threshold?

Relative to STS 1-in-90 projected LOC at program end? 

Relative to STS 1-in-67 demonstrated LOC?

Thanks for any insights.


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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #15 on: 08/24/2017 12:30 AM »
No idea: But STS had 1 in 50, so 2%. Seems NASA wS OK with that.

I think NASA was more in the "No Choice" category.  The shuttle had many design pieces that naturally lowered the LOC ratio.  (Fragile tiles, SRMs that can't be shut down once lit, seams in the TPS for the landing gears, etc.)  A capsule is inherently simpler and safer then the shuttle could ever be.  With the current LOC ratio they want, the shuttle would of never flown.  And remember, the LOC ratio they are shooting for wasn't a specific, science evaluated type number...they basically took the shuttle's (which they SAY was 1:90 but in reality was 1:50) and basically said "Lets triple that and be triple safe!!" and that was it.  The fact that they want something safer then has ever been done to date, but then have seemingly conflicting ways of calculating the LOC ratio in the first place, it is no wonder they are having a hard time reaching it...it was all kinda arbitrary to begin with in my opinion.

Offline Steven Pietrobon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #16 on: 08/24/2017 05:58 AM »
The article is saying the LOC is higher for on-orbit than during launch landing. That seems counter intuitive to me. The huge ISS has been up there for nearly 19 years without taking any major hits for debris. Historically, LOC has occurred during launch and entry.
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #17 on: 08/24/2017 06:04 AM »
The article is saying the LOC is higher for on-orbit than during launch landing. That seems counter intuitive to me. The huge ISS has been up there for nearly 19 years without taking any major hits for debris. Historically, LOC has occurred during launch and entry.
The ISS is mostly armored with whipple shields and Kevlar linings to deal with the MMOD. The CCP ships don't have that level of MMOD protection. Their MMOD protection is much better than that of Soyuz, but substantially less than that of the ISS.

But you don't hear ASAP complaining over the lack of MMOD protection of Soyuz. Simply because there currently is no alternative to Soyuz.
ASAP d*mn well knows that even suggesting to stop US HSF, until a "safe" spacecraft is available, is a non-starter.
So they keep whining about the inability of the CCP providers to meet arbitrarily set LOC/LOM numbers. But that has led to protracted efforts to meet those arbitrary LOC/LOM numbers. Which is silly given that the current LOC/LOM figures for the CCP ships are already well above those of Soyuz. So what you have here is ASAP directly contributing to a continuation of a less-safe situation for US HSF by having the introduction of the CCP ships delayed over some arbitrary LOC/LOM numbers.

And that is the prime reason why I really don't like the way in which ASAP operates.
« Last Edit: 08/24/2017 06:21 AM by woods170 »

Offline Rocket Science

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #18 on: 08/24/2017 12:33 PM »
All this had wringing would magically go away if Orion/SLS was the only US system of choice available to fly to ISS...
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Offline tdperk

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #19 on: 08/24/2017 01:09 PM »
All this had wringing would magically go away if Orion/SLS was the only US system of choice available to fly to ISS...

I have no reason to doubt it.


...it was all kinda arbitrary to begin with in my opinion.

Give that man a kewpie doll!
« Last Edit: 08/24/2017 01:19 PM by tdperk »

Offline whitelancer64

The article is saying the LOC is higher for on-orbit than during launch landing. That seems counter intuitive to me. The huge ISS has been up there for nearly 19 years without taking any major hits for debris. Historically, LOC has occurred during launch and entry.

Define "major hits."

The ISS has a couple of relatively big holes through its solar arrays and radiator panels, it's just luck that those MMOD impacts haven't done critical system damage. MMOD blankets have been replaced due to cumulative damage, and on spacewalks they now regularly do inspections for MMOD panels that may need to be replaced.
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Offline whitelancer64

*snip*

But you don't hear ASAP complaining over the lack of MMOD protection of Soyuz. Simply because there currently is no alternative to Soyuz.

*snip*

The Soyuz are covered with layers of thermal insulation with an outer MMOD protection layer.
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Offline john smith 19

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #22 on: 08/24/2017 04:20 PM »
All this had wringing would magically go away if Orion/SLS was the only US system of choice available to fly to ISS...
Yes it would be interesting to know just how much better (?) Orion is in this regard, given all the TLC NASA has lavished on the design over so many many years.  :(

I tend to view any person, or group, by what goals they say are important to them, and then by what activities they prioritize to reach those goals.

ASAP is saying this is the #1 hazard for crew transport vehicles in LEO.
What is NASA doing to clean up what's already there?
That's what causing this.
Slowing down (or stopping) making more is good, but how can you sweep a large volume of near Earth space cheaply of the very large number of objects too small for radar (IIRC everything < 5cm is invisible to ground radar) but still big enough to do damage?
If "Aerospace Safety" is their key task (which it is) shouldn't that be a key long term investigation for them?
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Offline whitelancer64

All this had wringing would magically go away if Orion/SLS was the only US system of choice available to fly to ISS...
Yes it would be interesting to know just how much better (?) Orion is in this regard, given all the TLC NASA has lavished on the design over so many many years.  :(

I tend to view any person, or group, by what goals they say are important to them, and then by what activities they prioritize to reach those goals.

ASAP is saying this is the #1 hazard for crew transport vehicles in LEO.
What is NASA doing to clean up what's already there?
That's what causing this.
Slowing down (or stopping) making more is good, but how can you sweep a large volume of near Earth space cheaply of the very large number of objects too small for radar (IIRC everything < 5cm is invisible to ground radar) but still big enough to do damage?
If "Aerospace Safety" is their key task (which it is) shouldn't that be a key long term investigation for them?

There are multiple threads on orbital debris cleanup. e.g., https://forum.nasaspaceflight.com/index.php?topic=35812.0

NASA has been studying the orbital debris problem since the 70s, and there is an Orbital Debris Program Office (established 1979), which btw issues a quarterly newsletter that is fascinating to read, they date back to 1996.

https://orbitaldebris.jsc.nasa.gov/quarterly-news/newsletter.html
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Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #24 on: 08/24/2017 05:18 PM »
*snip*

But you don't hear ASAP complaining over the lack of MMOD protection of Soyuz. Simply because there currently is no alternative to Soyuz.

*snip*

The Soyuz are covered with layers of thermal insulation with an outer MMOD protection layer.
Yes, and the "stopping power" of that set-up on Soyuz is considerably less than that of the CCP ships and almost non-existent compared to the set-up used on the USOS modules of ISS.

Offline whitelancer64

*snip*

But you don't hear ASAP complaining over the lack of MMOD protection of Soyuz. Simply because there currently is no alternative to Soyuz.

*snip*

The Soyuz are covered with layers of thermal insulation with an outer MMOD protection layer.
Yes, and the "stopping power" of that set-up on Soyuz is considerably less than that of the CCP ships and almost non-existent compared to the set-up used on the USOS modules of ISS.

If you say so.
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Offline deruch

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #26 on: 08/25/2017 01:17 AM »
From the article, and just so we more directly discuss/debate the issues:
Quote
The ASAP was presented with the three main “programmatic and safety risks” currently challenging the CCP, noted as the:

A. “inability to meet Loss of Crew (LOC) metrics
B. DoD’s Search and Rescue posture and capability
C. the possibility of aborts taking place in sea states that would be unsafe for rescue.”


It would seem to me that "B & C" might be easier to quantify and address, although both are contingent on weather and sea conditions that could change from moment to moment, which would be unpredictable.
B is about DoD budgets and basically the fact that the Navy isn't going to stage whole carrier fleets out on the launch track line because they don't have either the materiel or funding to support at that level while still accomplishing everything else they are tasked with doing.

C is just a restatement of the fact that there's pretty much no way for anyone to know the sea-state at every point along the potential abort track--with future forecasting far enough (for all such points) to allow for the delay of rescue assets to arrive on scene--such that they can guarantee an abort will land and stay in a sea that is safe for rescue.
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #27 on: 08/25/2017 03:51 AM »
I hope ASAP realises it has already won. The Commercial Crew spacecraft need to be the best not perfect.

To win the safety championship the Dragon V2, CST-100 and Dream Chaser need to safety ratings better that the Apollo Command Module, Shuttle and Soyuz.

At this point it is better for ASAP to ensure the companies have not missed anything. No oxygen tanks that will short out and explode.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #28 on: 08/25/2017 08:46 AM »
>
At this point it is better for ASAP to ensure the companies have not missed anything. No oxygen tanks that will short out and explode.

IMO, using solar power rather than fuel cells is a big safety step. Hopefully Kilopower will prove itself useful and up the ante for BEO.
« Last Edit: 08/25/2017 08:48 AM by docmordrid »
DM

Offline john smith 19

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #29 on: 08/26/2017 07:08 AM »
IMO, using solar power rather than fuel cells is a big safety step. Hopefully Kilopower will prove itself useful and up the ante for BEO.
Kilopower is still a ways from first ground test. I think it's got excellent prospects for use on future probes but its now the baseline for the Mars DRA because NASA already had a 40Kw nuclear reactor as one of their options.

I think it's a huge leap to consider it for human crewed BEO anytime soon.  :(
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #30 on: 08/27/2017 01:19 AM »
IMO, using solar power rather than fuel cells is a big safety step. Hopefully Kilopower will prove itself useful and up the ante for BEO.
Kilopower is still a ways from first ground test. I think it's got excellent prospects for use on future probes but its now the baseline for the Mars DRA because NASA already had a 40Kw nuclear reactor as one of their options.

I think it's a huge leap to consider it for human crewed BEO anytime soon.  :(

Kilopower should be available when a Moon base or Moon vehicle needs power. A robotic Moon base away from the poles is likely to need power. This will allow ASAP to measure the reliability in a working environment.

Offline john smith 19

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #31 on: 08/27/2017 06:18 AM »
Kilopower should be available when a Moon base or Moon vehicle needs power. A robotic Moon base away from the poles is likely to need power. This will allow ASAP to measure the reliability in a working environment.
That sounds like a much more plausible near term use, outside of on board power for an ion thruster driven outer planet probe, like to Saturn or Uranus.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C Apply So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Offline SWGlassPit

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #32 on: 09/01/2017 06:26 PM »
*snip*

But you don't hear ASAP complaining over the lack of MMOD protection of Soyuz. Simply because there currently is no alternative to Soyuz.

*snip*

The Soyuz are covered with layers of thermal insulation with an outer MMOD protection layer.
Yes, and the "stopping power" of that set-up on Soyuz is considerably less than that of the CCP ships and almost non-existent compared to the set-up used on the USOS modules of ISS.

If you say so.

woods170 is correct on this.  It's better than it was -- it got upgraded from "terrifying" to "not all that great."

Offline Oli

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #33 on: 09/04/2017 01:06 PM »
woods170 is correct on this.  It's better than it was -- it got upgraded from "terrifying" to "not all that great."

Gravity has taught us that Soyuz can be bombarded with orbital debris and still survive reentry.  :)
« Last Edit: 09/04/2017 01:14 PM by Oli »

Offline RonM

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #34 on: 09/04/2017 03:48 PM »
woods170 is correct on this.  It's better than it was -- it got upgraded from "terrifying" to "not all that great."

Gravity has taught us that Soyuz can be bombarded with orbital debris and still survive reentry.  :)

That was a Shenzhou. Wonder if anyone in the west looked at Shenzhou's LOC risks. Of course, because of Congress we'll never have a Shenzhou dock with ISS.

Offline Welsh Dragon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #35 on: 09/04/2017 06:32 PM »
Damnation upon both of you and all your offspring into eternity for making me remember that utter pile of bovine excrement after I'd just about successfully repressed it again, but it had both a Soyuz and Shenzou in it. The former gets pretty pelted as the ISS breaks up.

Offline savuporo

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #36 on: 09/04/2017 09:38 PM »
That was a Shenzhou. Wonder if anyone in the west looked at Shenzhou's LOC risks..

I'm gonna guess they are ahead of Soyuz simply by the virtue of not landing in Siberia and needing a TP-82 for protection from local fauna.
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Offline Patchouli

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #37 on: 09/05/2017 01:33 AM »
That was a Shenzhou. Wonder if anyone in the west looked at Shenzhou's LOC risks..

I'm gonna guess they are ahead of Soyuz simply by the virtue of not landing in Siberia and needing a TP-82 for protection from local fauna.

I think both the Star liner and Dragon beat Soyuz by having less separation events and three parachutes.

Though a crewed version of Dream Chaser in theory should beat both of them as far as landing safety goes.

That was one one part of STS that actually had a good safety record.
« Last Edit: 09/05/2017 01:36 AM by Patchouli »

Offline Proponent

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #38 on: 09/05/2017 01:19 PM »
I dunno about that.  IIRC, there was a report on Shuttle risks that identified the one-shot, high-speed landing as one of the larger risks.  One flight touched down short of the runway.

Offline Rocket Science

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #39 on: 09/05/2017 03:24 PM »
I dunno about that.  IIRC, there was a report on Shuttle risks that identified the one-shot, high-speed landing as one of the larger risks.  One flight touched down short of the runway.
Atlantis landed 600' short of the threshold at Rodgers Dry Lake and KSC SLF has a 1000' underun so it was no big deal for a PIC with a test pilot background, just more added excitement... The fact that the underun is available is part of the landing margin factored in...
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #40 on: 09/05/2017 04:36 PM »
I think both the Star liner and Dragon beat Soyuz by having less separation events and three parachutes.

Actually, Crew Dragon will have four parachutes.  But Apollo 15 did teach the lesson of having a one-chute-out safety margin... :)
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Offline ChrisWilson68

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #41 on: 09/30/2017 02:12 AM »
I think both the Star liner and Dragon beat Soyuz by having less separation events and three parachutes.

Though a crewed version of Dream Chaser in theory should beat both of them as far as landing safety goes.

That was one one part of STS that actually had a good safety record.

I disagree.  To land on a runway you give up being able to do ballistic re-entry.  Star liner and Dragon can lose all active control and go balistic and they'll come down fine.  All they need is the parachutes to pop open in a single event.  Space planes need control surfaces and active control all the way down.  It's much more complexity, which means more things that can go wrong.

Dragon is the safest in concept because it has a backup for the parachutes -- it can fire its Super Dracos if the parachutes don't open for some reason.

Offline rayleighscatter

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #42 on: 09/30/2017 09:50 PM »
Capsules can lose active control if they're already on the correct reentry path. Otherwise it will orbit forever, reenter too steep, or skip and then reenter too steep.

Offline Nibb31

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #43 on: 09/30/2017 09:56 PM »
Capsules can lose active control if they're already on the correct reentry path. Otherwise it will orbit forever, reenter too steep, or skip and then reenter too steep.

That is true for any reentry vehicle regardless of shape.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #44 on: 11/07/2017 06:16 AM »
I think both the Star liner and Dragon beat Soyuz by having less separation events and three parachutes.

Though a crewed version of Dream Chaser in theory should beat both of them as far as landing safety goes.

That was one one part of STS that actually had a good safety record.

I disagree.  To land on a runway you give up being able to do ballistic re-entry.  Star liner and Dragon can lose all active control and go balistic and they'll come down fine.  All they need is the parachutes to pop open in a single event.  Space planes need control surfaces and active control all the way down.  It's much more complexity, which means more things that can go wrong.

Dragon is the safest in concept because it has a backup for the parachutes -- it can fire its Super Dracos if the parachutes don't open for some reason.
I really hope they have added the software to do this. Just as CRS-7 dragon was lost due to lack of software to pop off nose cone it would be crap to loose a crew because parashutes failed despite having enough hydrazene in the tank for a landing.

Yes they have given up propulsive landing but only I think to the safety standard to do it every time. At the point of total parashutes failure who gives a darn what the chance of a safe propulsive landing is, it is their only hope!

Then again the chance of it firing when the parashutes are fine and shredding parashutes should be considered.


« Last Edit: 11/17/2017 11:09 AM by Chris Bergin »

Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #45 on: 11/12/2017 05:40 PM »
FWIW, to increase mission LOC/LOM now ... fly mission. Analyze. Rework. Fly again.

Why this doesn't happen ... IMO ... too much works too well ... the flights are cheaper/quicker than a certain bigger capsule ... CC converges on provable safety limits ... there then is pressure to actually fly crews.

Once crews start flying on CC, then there's pressure on the bigger capsule to do same. But it can't for cost/reasons, so everyone gets used to CC flying crew and the bigger capsule not flying crew.

This ends up not helping the big capsule, even though it should (a means to prove elements of big capsule with crew).

Because Congress doesn't want CC to follow Soyuz, they want the "big capsule" to. And, they can always blame CC for not flying, because "its too unsafe". Circular.

add:

What if CRS finds booster reuse is effective and accepts for flights? Then likewise CC might arrive at the same conclusion. NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.

How might 20-30 CRS/CC flights ... benefit LOC/LOM assessment/improvement? How much of this could also feed back into big capsule refinement? Might even improve Soyuz.
« Last Edit: 11/12/2017 05:46 PM by Space Ghost 1962 »

Offline rayleighscatter

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #46 on: 11/12/2017 08:14 PM »

NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.

What mission requires 30 CRS flights?

As upset as everyone gets for trying to invent missions for Orion then there's obviously no need to do it for CC either.

Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #47 on: 11/12/2017 08:56 PM »

NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.

What mission requires 30 CRS flights?

As upset as everyone gets for trying to invent missions for Orion then there's obviously no need to do it for CC either.
Missed the point. And its CRS/CC flights, because the same configuration could be used for both. Duh.

The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.

Not static, ground determined analysis. Sorry if I was unclear.

Edited by Lar.
« Last Edit: 11/14/2017 10:04 AM by Lar »

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #48 on: 11/12/2017 09:01 PM »

NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.

What mission requires 30 CRS flights?

As upset as everyone gets for trying to invent missions for Orion then there's obviously no need to do it for CC either.

30 CRS flights would support multiple Moon landings. Using 5 tonne payloads it will take a while to construct a lunar base. At 40 tonnes payload to the Moon entire buildings can be delivered in one go.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #49 on: 11/13/2017 07:13 AM »

NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.

What mission requires 30 CRS flights?

As upset as everyone gets for trying to invent missions for Orion then there's obviously no need to do it for CC either.
Missed the point. And its CRS/CC flights, because the same configuration could be used for both. Duh.

The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.

Not static, ground determined analysis. Perhaps I need to resort to purple crayon to get my point across?  ::)
Your point is clear. Two little flaws though:
- There won't be 30 missions to inform crew safety, not even when you add Cargo Dragon v2 missions into the mix.
- Purely commercial, non-NASA missions, such as the planned circumlunar mission, do not inform crew safety because NASA insight into those will be almost non-existent.

Right now the CRS/CCP providers need NASA to survive. As such they are willing to put up with the additional crew-safety burden that NASA places on them. But IMO there will come a time when at least one of those providers no longer needs NASA to achieve its goals. When that time comes it will shed NASA and its associated burdensome bureaucracy. Regardless of its his current habit of praising NASA.
« Last Edit: 11/13/2017 07:14 AM by woods170 »

Offline pathfinder_01

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #50 on: 11/13/2017 07:50 AM »


Because Congress doesn't want CC to follow Soyuz, they want the "big capsule" to. And, they can always blame CC for not flying, because "its too unsafe". Circular.

add:

What if CRS finds booster reuse is effective and accepts for flights? Then likewise CC might arrive at the same conclusion. NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.

How might 20-30 CRS/CC flights ... benefit LOC/LOM assessment/improvement? How much of this could also feed back into big capsule refinement? Might even improve Soyuz.

1.  This isn't a Congress problem. Congress wants SLS because it creates the most jobs. Orion less so. Therefore Orion development takes a back seat to SLS development. It isn't like Apollo and the early space race where no new rockets were developed specifically for Mercury and Gemini(as that would only delay things) and Apollo used the Saturn 1B(which was an upgrade of an existing rocket) for a number of test flights. This is an ASAP problem. If they were interested in improving the safety of Orion they could always fly some of them on Delta IV heavy but that would require development which would take even more budget(or reduce budget to SLS, therefore delay is the better Option).

2.  There would only be limited data from Commercial Crew that would be relevant to Orion or Soyuz as one system was in development before commercial crew and the other was operational long before. The Russians already have a much more relevant data set for Soyuz and it' successors.

3. As much as I would love a block buy of 20-30 flight this isn't a good reason.  20-30 flights would improve Dragon 2 and Starliner by finding the problems that only experience could sort out. They say little to nothing about Orion.
« Last Edit: 11/13/2017 07:56 AM by pathfinder_01 »

Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #51 on: 11/13/2017 09:59 PM »
NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.
What mission requires 30 CRS flights?
The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.
Your point is clear. Two little flaws though:
- There won't be 30 missions to inform crew safety, not even when you add Cargo Dragon v2 missions into the mix.
- Purely commercial, non-NASA missions, such as the planned circumlunar mission, do not inform crew safety because NASA insight into those will be almost non-existent.
1. Builds on my point. We think of such vehicles as a limiting cost and so minimize to fewest use. Which caps are ability to reach ASAP's desired LOC. Past LV reuse, things get safer/cheap in net when we get to a fair fraction of 100. SX likely to reach hundreds of missions off of reuse, so we're likely to reach comparative numbers to Shuttle.
2. AF contracts require all launches to "inform" on LV performance. A similar means to inform on crew safety under appropriate convention (possible in US but not Europe given certain laws) could supply such, part of adventurer contract of carriage.

Am quite serious about means to achieve best provable crew vehicle LOC. Which is potentially transferable to other vehicles.

Quote
Right now the CRS/CCP providers need NASA to survive. As such they are willing to put up with the additional crew-safety burden that NASA places on them. But IMO there will come a time when at least one of those providers no longer needs NASA to achieve its goals. When that time comes it will shed NASA and its associated burdensome bureaucracy. Regardless of its his current habit of praising NASA.
Yes we are both looking at the same thing. Beyond NASA. Where its just an occasional client.

BTW, there are many "NASA's" inside of NASA. True of other agencies/ministries. Some see this too.

Difference might be about where and how to achieve said "pivot". Perhaps as temporary conservator? Thus the above.

Offline rayleighscatter

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #52 on: 11/25/2017 01:56 PM »
NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.
What mission requires 30 CRS flights?
The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.
Your point is clear. Two little flaws though:
- There won't be 30 missions to inform crew safety, not even when you add Cargo Dragon v2 missions into the mix.
- Purely commercial, non-NASA missions, such as the planned circumlunar mission, do not inform crew safety because NASA insight into those will be almost non-existent.
1. Builds on my point. We think of such vehicles as a limiting cost and so minimize to fewest use. Which caps are ability to reach ASAP's desired LOC. Past LV reuse, things get safer/cheap in net when we get to a fair fraction of 100. SX likely to reach hundreds of missions off of reuse, so we're likely to reach comparative numbers to Shuttle.
2. AF contracts require all launches to "inform" on LV performance. A similar means to inform on crew safety under appropriate convention (possible in US but not Europe given certain laws) could supply such, part of adventurer contract of carriage.

Am quite serious about means to achieve best provable crew vehicle LOC. Which is potentially transferable to other vehicles.

Quote
Right now the CRS/CCP providers need NASA to survive. As such they are willing to put up with the additional crew-safety burden that NASA places on them. But IMO there will come a time when at least one of those providers no longer needs NASA to achieve its goals. When that time comes it will shed NASA and its associated burdensome bureaucracy. Regardless of its his current habit of praising NASA.
Yes we are both looking at the same thing. Beyond NASA. Where its just an occasional client.

BTW, there are many "NASA's" inside of NASA. True of other agencies/ministries. Some see this too.

Difference might be about where and how to achieve said "pivot". Perhaps as temporary conservator? Thus the above.

So what you are proposing is that commercial providers surrender their technology and data to the public good? Because that proposal isn't compatible with the current proprietary nature. Unless the intent is to create a de-facto eternal duopoly.

Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #53 on: 11/26/2017 06:00 PM »
So what you are proposing is that commercial providers surrender their technology and data to the public good?
Would you please explain this otherwise irrational conclusion?

Referenced posts say nothing of the kind. Perhaps something else not visible, possibly emotional, is being triggered?

Honestly have no idea where this comes from in the above discussion and would like to know if substantive, because it entirely escapes me and frankly no I don't comment to annoy anyone here as that is my only conclusion as to meaning.

Quote
Because that proposal isn't compatible with the current proprietary nature. Unless the intent is to create a de-facto eternal duopoly.
When has anyone advocated that, please?

Don't get any of this. Asking for advice/help from others, as I'm completely at sea here - help!

Online AncientU

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #54 on: 11/27/2017 07:33 PM »
...

Quote
Right now the CRS/CCP providers need NASA to survive. As such they are willing to put up with the additional crew-safety burden that NASA places on them. But IMO there will come a time when at least one of those providers no longer needs NASA to achieve its goals. When that time comes it will shed NASA and its associated burdensome bureaucracy. Regardless of its his current habit of praising NASA.
Yes we are both looking at the same thing. Beyond NASA. Where its just an occasional client.
...

NASA is asking for one crew flight per year from each of its two providers.  Both GS and EM have said that the demand for tourist flights is surprisingly robust -- which easily translates to more than one flight per year.  Why is 'Beyond NASA' envisioned as so desolate?
« Last Edit: 11/27/2017 07:34 PM by AncientU »
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #55 on: 11/27/2017 07:40 PM »
So what you are proposing is that commercial providers surrender their technology and data to the public good?
Would you please explain this otherwise irrational conclusion?

Referenced posts say nothing of the kind. Perhaps something else not visible, possibly emotional, is being triggered?

Honestly have no idea where this comes from in the above discussion and would like to know if substantive, because it entirely escapes me and frankly no I don't comment to annoy anyone here as that is my only conclusion as to meaning.

Quote
Because that proposal isn't compatible with the current proprietary nature. Unless the intent is to create a de-facto eternal duopoly.
When has anyone advocated that, please?

Don't get any of this. Asking for advice/help from others, as I'm completely at sea here - help!

Haven't a clue what is meant here...
"If we shared everything [we are working on] people would think we are insane!"
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Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #56 on: 11/28/2017 12:30 AM »
Thank you. It's nice to get confirmation that it's not just me. Worry sometimes that I say something that is wrong in a way I don't anticipate.

Offline rayleighscatter

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #57 on: 12/28/2017 07:13 PM »
Ok, to simplify then:


The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.

How is this accomplished? Do other companies get access to the flight/machine data, or do all future contacts go to the same two companies because they're the only ones who have access to the data needed to improve safety.

Unless you have another thought in mind on how, say, Lockheed could benefit from SpaceX's proprietary heatshield designs and data.
« Last Edit: 12/28/2017 08:52 PM by rayleighscatter »

Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #58 on: 12/28/2017 09:01 PM »
Ok, to dumb it down then:


The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.

How is this accomplished? Do other companies get access to the flight/machine data, or do all future contacts go to the same two companies because they're the only ones who have access to the data needed to improve safety.

Unless you have another thought in mind on how, say, Lockheed could benefit from SpaceX's proprietary heatshield designs and data.
Perhaps you are unaware of prior practice.

All past HSF vehicles "inform" on safety/"best practices". Apart from proprietary implementation "flight data". Various groups/agencies/institutions are issued study contracts to take mission flight data and issue a study to find/characterize specific risks. This is used by those including ASAP to feed back to vendors/providers what to look for in refining/qualifying HSF SC/components/subsystems for use. At least with earlier vehicles/modules.

So, there's this new snazzy thing called "Big data", where how this is communicated is in specific "non flight data" form that fits into everyone's models, to specifically address particular concerns. (It's cleverly done so you can't abstract performance data from it.)

It's a similar treatment to how other aerospace standards of practice are improved upon.

But no,  not letting everyone see each others "stuff", but learning from "incidents". Like with airlines/munitions.

Oh, and there are legal/contractual terms too. Not like the "bad old days".

Online envy887

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #59 on: 01/17/2018 04:03 PM »
SpaceX's view on the prop loading and COVP issues, from Hans Koenigsmann's testimony

Quote
At SpaceX, every design and operation decision is driven by safety and reliability. SpaceX recognizes that
some proposed operating procedures for the crew transportation system differ from those on the Space
Shuttle Program. SpaceX has elected to adopt certain approaches, including propellant loading after
astronauts have been secured in the spacecraft and the launch escape system is enabled, because they offer
the potential to improve safety for both astronauts and ground crew. Under SpaceX’s operations plan, after
astronauts board the spacecraft, the ground crew will close out the vehicle and will leave the launch site.
Launch vehicle propellant loading will begin only after the escape system is armed. This approach ensures
that astronauts have escape capability during any time propellant is on the launch vehicle, and it does not
expose ground crew to unnecessary risk. Notably, the Space Shuttle continued loading liquid hydrogen for
three hours (“Space Shuttle Replenish” procedure) after astronauts were aboard; propellant loading on
Falcon 9 consumes approximately 30 minutes, reducing the time astronauts are exposed to loading
operations.

We have also worked closely with NASA to further enhance the robustness of our composite overwrapped
pressure vessels (COPVs) and to ensure NASA is comfortable with their performance in a variety of flight
environments. We are confident that this process is safe, and we are working closely with NASA to
complete the ongoing, rigorous analysis necessary to achieve certification.
https://democrats-science.house.gov/sites/democrats.science.house.gov/files/documents/Koenigsmann%20Testimony.pdf

Not sure I agree with this logic (as risk and exposure time are not necessarily directly correlated) but it sounds like SpaceX expects to certify this prop loading procedure.

Offline punder

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #60 on: 01/17/2018 05:01 PM »
The logic of prop-loading the F9 after crew boarding is absolutely unassailable. How could working near a fueled, pressurized rocket, and boarding crew on a fueled, pressurized rocket, be safer than evacuating the pad and securing the crew in a LES-equipped capsule before any prop begins to flow? How???

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.
« Last Edit: 01/17/2018 05:07 PM by punder »

Offline mn

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #61 on: 01/17/2018 06:07 PM »
The logic of prop-loading the F9 after crew boarding is absolutely unassailable. How could working near a fueled, pressurized rocket, and boarding crew on a fueled, pressurized rocket, be safer than evacuating the pad and securing the crew in a LES-equipped capsule before any prop begins to flow? How???

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.

I suspect this has been discussed many times here (I did read it here at least once before no idea which thread).

The process of loading can easily be considered more dangerous than after loading is complete. There is lots of things going on during loading, once you are done you are in a stable state.

(this has been argued back and forth, I'm not saying absolutely one way is right, but there is certainly enough doubt that you cannot say 'How???')

I suspect that historically there were more anomalies during loading than after loading and before launch (if there is even enough incidents to create a meaningful statistic).

Offline deruch

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #62 on: 01/17/2018 06:25 PM »
The logic of prop-loading the F9 after crew boarding is absolutely unassailable. How could working near a fueled, pressurized rocket, and boarding crew on a fueled, pressurized rocket, be safer than evacuating the pad and securing the crew in a LES-equipped capsule before any prop begins to flow? How???

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.

Because the highest danger is during fueling.  It's a dynamic process both in terms of the propellants themselves flowing but also the vehicle hasn't reached thermal stasis.  The danger that something goes wrong and causes an accident is much higher during this period than that it is during the relatively static period of topping-off/replenishment.  So, that added risk has to be weighed against the lower risk of fewer man minutes of exposure to a loaded rocket.  Exactly which one turns out to have the true lower risk is dependent on the variables: number of astronauts and ground crew exposed, loading duration, etc.
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Online envy887

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #63 on: 01/17/2018 06:42 PM »
The logic of prop-loading the F9 after crew boarding is absolutely unassailable. How could working near a fueled, pressurized rocket, and boarding crew on a fueled, pressurized rocket, be safer than evacuating the pad and securing the crew in a LES-equipped capsule before any prop begins to flow? How???

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.

No rocket is pressurized for flight until the final seconds of countdown, as far as I know. So crew weren't working on a pressurized, fueled rocket with either Shuttle or Titan II. There is only head pressure at the bottom of the tanks from the weight of the propellant higher up, but no flight pressurants.

AMOS-6 is a pretty good example of why exposure time and risk are not correlated. The LOX tank and the COPVs were being filled, with pressures, fill levels, and temperatures constantly changing until they reached an unstable point that hadn't been reached before, resulting in the explosion.

Once filled, everything on a non-sub-cooled rocket is basically in steady state and can sit with occasional topping for boiloff for as long as you want with nothing really changing. This doesn't really work for a subcooled rocket.

SpaceX wants to make the process inherently safe and controlled. Every other type of vehicle is fueled with passengers and crew aboard. But they have a lot of work to do to prove that Falcon 9 is just as safe as other vehicles, since the fuels are inherently more dangerous.
« Last Edit: 01/17/2018 06:45 PM by envy887 »

Offline punder

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #64 on: 01/17/2018 07:06 PM »
Difficult to see how pad crew that have evacuated the pad, can be injured by a prop-loading mishap, when the prop-loading begins only after they have evacuated the pad.

So right there, the number of personnel exposed to danger has been halved or more than halved.

The remaining personnel still in danger--the flight crew--are sitting in a fully armed launch escape system that necessarily features, as part of its fundamental design, successful operation upon detection of a sudden, unanticipated booster explosion on the pad. Of course the LES doesn't eliminate the risk of LOC but without it, the LOC probability is 1.


Offline punder

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #65 on: 01/17/2018 07:19 PM »
The logic of prop-loading the F9 after crew boarding is absolutely unassailable. How could working near a fueled, pressurized rocket, and boarding crew on a fueled, pressurized rocket, be safer than evacuating the pad and securing the crew in a LES-equipped capsule before any prop begins to flow? How???

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.

No rocket is pressurized for flight until the final seconds of countdown, as far as I know. So crew weren't working on a pressurized, fueled rocket with either Shuttle or Titan II. There is only head pressure at the bottom of the tanks from the weight of the propellant higher up, but no flight pressurants.

AMOS-6 is a pretty good example of why exposure time and risk are not correlated. The LOX tank and the COPVs were being filled, with pressures, fill levels, and temperatures constantly changing until they reached an unstable point that hadn't been reached before, resulting in the explosion.

Once filled, everything on a non-sub-cooled rocket is basically in steady state and can sit with occasional topping for boiloff for as long as you want with nothing really changing. This doesn't really work for a subcooled rocket.

SpaceX wants to make the process inherently safe and controlled. Every other type of vehicle is fueled with passengers and crew aboard. But they have a lot of work to do to prove that Falcon 9 is just as safe as other vehicles, since the fuels are inherently more dangerous.

The Titan II fatalities occurred in operational silos where the Titans were fully fueled and capable of being brought to flight pressures within minutes.

http://www.themilitarystandard.com/missile/titan2/accident_374-7_1976.php
http://www.themilitarystandard.com/missile/titan2/littlerockaccident.php
http://www.themilitarystandard.com/missile/titan2/accident_533-7_1978.php


Offline Rocket Science

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #66 on: 01/17/2018 07:26 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o
"The laws of physics are unforgiving"
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Offline punder

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #67 on: 01/17/2018 08:09 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.

Offline rayleighscatter

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #68 on: 01/17/2018 09:02 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.

It's statistical analysis.

It's the same reason it's fine for them to store large amounts of fuel and oxidizer on site for months and have people working around them, but why no extraneous personnel can be around when it's transferred from the trucks.
 

Offline Negan

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #69 on: 01/17/2018 09:24 PM »
The logic of prop-loading the F9 after crew boarding is absolutely unassailable. How could working near a fueled, pressurized rocket, and boarding crew on a fueled, pressurized rocket, be safer than evacuating the pad and securing the crew in a LES-equipped capsule before any prop begins to flow? How???

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.

Sad part is SpaceX has already proved at least 38 times in a row they can safely fuel F9 without blowing it up, and that's with some flight-proven 1st stages in the mix.

Edit: Not to mention "returning helium loading operations to a prior flight proven configuration based on operations used in over 700 successful COPV loads"
« Last Edit: 01/17/2018 10:01 PM by Negan »

Offline punder

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #70 on: 01/17/2018 09:35 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.

It's statistical analysis.

It's the same reason it's fine for them to store large amounts of fuel and oxidizer on site for months and have people working around them, but why no extraneous personnel can be around when it's transferred from the trucks.

Must be a case of dueling statistical analyses.   :)

Offline Rocket Science

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #71 on: 01/17/2018 10:09 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.
Nah, it's all good... We have to pass the time until we "finally" get to launch crews from US soil again whoever goes first! :)
"The laws of physics are unforgiving"
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Offline mn

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #72 on: 01/17/2018 11:01 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.

Nobody ever said that entering the empty vehicle was more dangerous, the danger is in the fueling process and the question is do you want the crew sitting there during that process.

Offline butters

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #73 on: 01/17/2018 11:14 PM »
Loading prop after crew ingress increases the risk of a pad abort by some unknown amount. Loading prop before crew ingress might slightly increase the risk to flight and ground crew during ingress prior to LES activation. Which is safer depends on the probability of an emergency during prop load combined with the success rate of LES on pad aborts, as compared to the probability of an emergency during replenishment and the prospects for escaping such an emergency via the slidewires.

The risk of something going very wrong during replenishment should be significantly lower than the risk during prop load. But the odds of a successful escape should be significantly higher with the LES. It's not a straightforward comparison.

Offline punder

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #74 on: 01/17/2018 11:25 PM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.

Nobody ever said that entering the empty vehicle was more dangerous, the danger is in the fueling process and the question is do you want the crew sitting there during that process.

I see your point, but given a launch escape system, I'd say yes. Are you listening, NASA?   :D

I'm a train nut who gets nervous just standing next to old steam engines at 200 psi... they have occasionally launched their boilers into short but highly spectacular suborbital trajectories, with entirely predictable consequences for the unfortunate cab crew. (Sorry OT.)

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #75 on: 01/17/2018 11:52 PM »

The Titan II killed or injured several pad workers in this exact scenario--while they were working on or near a fully fueled, pressurized rocket.

No, not in this exact scenario. For one accident, they were disconnecting a pressurization line and a quick disconnect did not work.    The other accident, a worker dropped a large socket that punctured the fuel tank.    Not the same as loading a crew.

Offline Steven Pietrobon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #76 on: 01/18/2018 05:17 AM »
Sad part is SpaceX has already proved at least 38 times in a row they can safely fuel F9 without blowing it up, and that's with some flight-proven 1st stages in the mix.

That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6. Lets try and get some numbers. I made some engineering guestimates.

Probability vehicle fails after loading = p = 0.01 (an engineering guess upper bound)
Probability vehicle fails during loading = 2*p = 0.02 (this is twice more dangerous)
Probability escape vehicle fails = q = 0.1 (remember seeing this somewhere)
Probability fail to get away from vehicle during fuelling = 2*q = 0.2 (assume twice more dangerous)
Number of flight crew = n = 4
Number of ground crew = n = 4 (assume same as flight crew)
Assume time to load propellants is same as time to load crew (half an hour).

Expected loss standard procedure = 2*n*2*q*p = 4*n*p = 0.016
Expected loss SpaceX procedure = n*q*2*p = 0.008

What this shows is that the SpaceX procedure is safer because less people are exposed to risk and that the crew escape system is safer than having the ground and flight crew try and get away using slide wires. As the Space Shuttle did not have an escape system, the standard procedure is the safest way.
« Last Edit: 01/18/2018 05:18 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline watermod

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #77 on: 01/18/2018 05:40 AM »
So are the Dragon and the Starliner more dangerous for the astronauts to fly in then the Soyuz?    If not then NASA and the Congress should find other battles to quibble over.   If it is more dangerous than quibble away.

Offline Steven Pietrobon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #78 on: 01/18/2018 05:43 AM »
So are the Dragon and the Starliner more dangerous for the astronauts to fly in then the Soyuz?

I would say yes as both of these vehicles are unproven.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline deruch

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #79 on: 01/18/2018 06:22 AM »
Sad part is SpaceX has already proved at least 38 times in a row they can safely fuel F9 without blowing it up, and that's with some flight-proven 1st stages in the mix.

That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6. Lets try and get some numbers. I made some engineering guestimates.

Probability vehicle fails after loading = p = 0.01 (an engineering guess upper bound)
Probability vehicle fails during loading = 2*p = 0.02 (this is twice more dangerous)
Probability escape vehicle fails = q = 0.1 (remember seeing this somewhere)
Probability fail to get away from vehicle during fuelling = 2*q = 0.2 (assume twice more dangerous)
Number of flight crew = n = 4
Number of ground crew = n = 4 (assume same as flight crew)
Assume time to load propellants is same as time to load crew (half an hour).

Expected loss standard procedure = 2*n*2*q*p = 4*n*p = 0.016
Expected loss SpaceX procedure = n*q*2*p = 0.008

What this shows is that the SpaceX procedure is safer because less people are exposed to risk and that the crew escape system is safer than having the ground and flight crew try and get away using slide wires. As the Space Shuttle did not have an escape system, the standard procedure is the safest way.

And how do your numbers work if the probability of failure during fueling is 5 or 10 or 20 times higher than the static condition or if ground crew numbers are larger/smaller?  That's the point.  The relative safety is highly dependent on the variables and as outsiders we don't have a good idea of how they are determined/supported.  SpaceX obviously thinks their procedures are safer, NASA may remain skeptical.  But, neither position is unreasonable from their respective positions.  It's only right that SpaceX believes in their processes (so long as they have the test data to back them up) and it's right for NASA to make them prove it.  The only no-nos are for SpaceX to stick to their method "just because" or for NASA to stubbornly reject it even in the face of good supporting data because it's NIH (not invented here; i.e. not the way we've always done it).
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Offline john smith 19

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #80 on: 01/18/2018 07:06 AM »

Expected loss standard procedure = 2*n*2*q*p = 4*n*p = 0.016
Expected loss SpaceX procedure = n*q*2*p = 0.008

What this shows is that the SpaceX procedure is safer because less people are exposed to risk and that the crew escape system is safer than having the ground and flight crew try and get away using slide wires. As the Space Shuttle did not have an escape system, the standard procedure is the safest way.
Which suggests (no proof, just suggests) that ASAP is thinking that programme vehicles don't have launch escape systems designed in, IE just like Shuttle.

This is simply bizarre, given they they know both capsules do (and DC will) and IIRC didn't they insist on them having such systems to begin with?

In aviation, loading passengers happens after the vehicle is fueled. This has (potentially) serious implications for ConOps with any future P2P BFS flights.
OTOH getting unstrapped from a capsule and running in a full pressure suit is a PITA.
However if you're in the same capsule with a finger poised over the Big Red Switch to fire the LES and watching any vehicle telemetry for anomalies that sounds quite a bit safer than being crew on the pad.

My instinct is go to the toilet, suit up and strap in then let the pad crew do their work, while being ready to punch out if anything looks off.
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C Apply So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Online rockets4life97

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #81 on: 01/18/2018 07:07 AM »
Sad part is SpaceX has already proved at least 38 times in a row they can safely fuel F9 without blowing it up, and that's with some flight-proven 1st stages in the mix.

That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.

Negan is counting static fires. Should probably also count test fires at McGregor. So the number of successful fires with the current procedure is probably >50.

Offline deruch

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #82 on: 01/18/2018 08:20 AM »
Sad part is SpaceX has already proved at least 38 times in a row they can safely fuel F9 without blowing it up, and that's with some flight-proven 1st stages in the mix.

That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.

Negan is counting static fires. Should probably also count test fires at McGregor. So the number of successful fires with the current procedure is probably >50.

That makes some assumptions that aren't necessarily supported though.  Firstly, McGregor firings are of each stage individually and not of a combined stack.  Seems like this shouldn't really be a factor, but maybe there is some unexpected difference.  Secondly, while I have a hard time believing that this would be so, IIRC, we don't actually know that the loading process at McGregor is exactly the same as at the launch pad.  Slightly more believable is that environmental factors could be a factor. 

With the static fires, we absolutely know that it is being done the same as on launch day.  So, while you're probably right that there have been more successful firings with the current procedure, I don't think we can yet say so definitively.
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Offline Rocket Science

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #83 on: 01/18/2018 08:29 AM »

Expected loss standard procedure = 2*n*2*q*p = 4*n*p = 0.016
Expected loss SpaceX procedure = n*q*2*p = 0.008

What this shows is that the SpaceX procedure is safer because less people are exposed to risk and that the crew escape system is safer than having the ground and flight crew try and get away using slide wires. As the Space Shuttle did not have an escape system, the standard procedure is the safest way.
Which suggests (no proof, just suggests) that ASAP is thinking that programme vehicles don't have launch escape systems designed in, IE just like Shuttle.

This is simply bizarre, given they they know both capsules do (and DC will) and IIRC didn't they insist on them having such systems to begin with?

In aviation, loading passengers happens after the vehicle is fueled. This has (potentially) serious implications for ConOps with any future P2P BFS flights.
OTOH getting unstrapped from a capsule and running in a full pressure suit is a PITA.
However if you're in the same capsule with a finger poised over the Big Red Switch to fire the LES and watching any vehicle telemetry for anomalies that sounds quite a bit safer than being crew on the pad.

My instinct is go to the toilet, suit up and strap in then let the pad crew do their work, while being ready to punch out if anything looks off.
John, passengers  have stayed boarded during refueling stops. If vapors are detected they can be asked to deplane...
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Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #84 on: 01/18/2018 09:17 AM »
Because the highest danger is during fueling.  It's a dynamic process both in terms of the propellants themselves flowing but also the vehicle hasn't reached thermal stasis.  The danger that something goes wrong and causes an accident is much higher during this period than that it is during the relatively static period of topping-off/replenishment.  So, that added risk has to be weighed against the lower risk of fewer man minutes of exposure to a loaded rocket.  Exactly which one turns out to have the true lower risk is dependent on the variables: number of astronauts and ground crew exposed, loading duration, etc.

Emphasis mine.

"Relative" is the right word here. You see, there is nothing static about topping-off/replenishment:

- Valves are opening and closing, both on GSE and the launch vehicle. Propellant flow intermittently starts and stops, causing small, but significant rises and drops in propellant pressure in both GSE and the launch vehicle.
- Intermittent instances of venting, the result of a rise in tank-pressure. The venting results in a dropping tank-pressure. So, the tanks are constantly "breathing" which results in continues cycles of expanding/shrinking.
- People sometimes cite thermal equilibrium as the thing being "static". But that is not correct either. Temperature of parts of the launcher continue to drop well after topping-off/replenishment has started. The STS ET, for example, continued to "shrink" for almost an hour into the stable replenishment cycle because that first hour into the replenishment-cycle there was no thermal equilibrium.

Offline jak Kennedy

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #85 on: 01/18/2018 09:56 AM »
I wonder what ASAP had to say about fuel transfers to the ISS? And next fuel depots in space. Although a different environment it will become SOP (or has) one day with crew onboard.

Online envy887

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #86 on: 01/18/2018 01:19 PM »
Sad part is SpaceX has already proved at least 38 times in a row they can safely fuel F9 without blowing it up, and that's with some flight-proven 1st stages in the mix.

That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.

Negan is counting static fires. Should probably also count test fires at McGregor. So the number of successful fires with the current procedure is probably >50.

That makes some assumptions that aren't necessarily supported though.  Firstly, McGregor firings are of each stage individually and not of a combined stack.  Seems like this shouldn't really be a factor, but maybe there is some unexpected difference.  Secondly, while I have a hard time believing that this would be so, IIRC, we don't actually know that the loading process at McGregor is exactly the same as at the launch pad.  Slightly more believable is that environmental factors could be a factor. 

With the static fires, we absolutely know that it is being done the same as on launch day.  So, while you're probably right that there have been more successful firings with the current procedure, I don't think we can yet say so definitively.

Prop load during WDRs are also done the same as launch day, and Zuma did two of those and FH at least 1.

Seven Block 5 flights will be at least 42 stage loads (2x stages, 3x loads each counting McGregor), and probably >50 loads because each FH gets 12 stage loads, and Block 5 might get extra tests or WDRs.

Offline spacenut

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #87 on: 01/18/2018 02:12 PM »
I don't like that NASA required SpaceX to remove the landing legs and go with water landings.  Yet Boeing can use air bags and do land landings.  Seems like a waste of innovation.

Does anyone think SpaceX will eventually go back to landing legs for non-NASA flights?

« Last Edit: 01/18/2018 02:13 PM by spacenut »

Offline kevinof

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #88 on: 01/18/2018 02:33 PM »
Nope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?

Offline abaddon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #89 on: 01/18/2018 03:03 PM »
That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.
Wrong, static fires fully fuel the vehicle, and every launch has been preceded by a static fire.  The originally cited 38 is correct.

Offline abaddon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #90 on: 01/18/2018 03:08 PM »
As an aside, whatever risk there is in Astros needing to use the Boeing crew escape system (the slide wire) from the pad must be accounted for.  I would assume the estimated level of risk in using the system itself is generally considered to be low.  Presumably the window of time where it would be used is also low, as once the Astros are in the craft and buckled in, the LES should take over responsibility rather than using the slide wire.

Also worth noting that SpaceX has no equivalent system because of their plans to board unfueled.  If at some point those plans change, they will presumably have to implement a crew escape system similar to Boeing's.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #91 on: 01/18/2018 03:44 PM »
As an aside, whatever risk there is in Astros needing to use the Boeing crew escape system (the slide wire) from the pad must be accounted for.  I would assume the estimated level of risk in using the system itself is generally considered to be low.  Presumably the window of time where it would be used is also low, as once the Astros are in the craft and buckled in, the LES should take over responsibility rather than using the slide wire.

Also worth noting that SpaceX has no equivalent system because of their plans to board unfueled.  If at some point those plans change, they will presumably have to implement a crew escape system similar to Boeing's.

Which will add delay. Which will be the fault of SpaceX even if NASA or congress mandates it.

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Offline gongora

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #92 on: 01/18/2018 03:55 PM »
Also worth noting that SpaceX has no equivalent system because of their plans to board unfueled.  If at some point those plans change, they will presumably have to implement a crew escape system similar to Boeing's.

I thought SpaceX is also going to have a slide wire system on 39A?

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #93 on: 01/18/2018 04:03 PM »
Also worth noting that SpaceX has no equivalent system because of their plans to board unfueled.  If at some point those plans change, they will presumably have to implement a crew escape system similar to Boeing's.

I thought SpaceX is also going to have a slide wire system on 39A?

There already was a slide wire system.  I don’t know what state it was in but I can probably dig up pictures from just before 39A handover

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #94 on: 01/18/2018 06:00 PM »
I wonder what ASAP had to say about fuel transfers to the ISS? And next fuel depots in space. Although a different environment it will become SOP (or has) one day with crew onboard.

ASAP has nothing to say about that, given that fuel transfer to the ISS is already happening, on a regular basis, on the Russian Segment. It was done on five (5) ATV missions and Progress freighters also regularly transfer fuel into the tanks of the Zvezda module.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #95 on: 01/18/2018 06:03 PM »
Also worth noting that SpaceX has no equivalent system because of their plans to board unfueled.  If at some point those plans change, they will presumably have to implement a crew escape system similar to Boeing's.

I thought SpaceX is also going to have a slide wire system on 39A?

That was the plan once. But plans may have changed when they switched to fueling after the crew has boarded. Don't know if the slide wires will still be there.

Online Robotbeat

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #96 on: 01/19/2018 04:11 AM »
Wow this thread is like Deja vu all over again from AMOS-6... :o

Sorry if I'm annoying people. I just can't wrap my head around the idea that working around, riding an elevator beside, climbing into etc. an empty shell might be considered more dangerous than doing the same things when the empty shell has been transformed into a very large bomb.

It's statistical analysis.

It's the same reason it's fine for them to store large amounts of fuel and oxidizer on site for months and have people working around them, but why no extraneous personnel can be around when it's transferred from the trucks.
Statistical analysis? I doubt it.

NASA likes to do things like not count, say, the LAS as part of the safety situation when analyzing such things because "LAS is only for last resort." (Oh, and treating pad crew separate from astronaut.) That's not very statistically sound and can end up being MUCH, MUCH less safe. For example:

Let's say, not counting LAS, that loading the astronauts in the capsule, then fueling it up, is twice as dangerous to the astronauts as fueling the vehicle and THEN loading the astronauts.

"LAS is a last resort, so we can't count it." Uh huh. However, pad abort is something the LAS should be particularly good at since the vehicle isn't even moving, but let's give it just a 9/10 chance of success.

That means that, if you count the system as it ACTUALLY is, with LAS and everything, it's fully FIVE TIMES safer the put the astronauts in the LAS-equipped capsule before fueling than after.

Not only that, but it's like (nearly) infinitely safer for the pad crew to evacuate them before fueling the rocket!

This sort of rule-based safety culture, which can ignore actual full resultant risk when making decisions, seems pervasive at NASA just by talking to people. But Gerstenmeier (who always impresses me) in his testimony said that NASA won't play those word games and instead will do a fair safety assessment.

I hope so.
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #97 on: 01/19/2018 08:27 AM »
Nope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?

Because SpaceX will want to get the BFR's launch escape system (LES) to a high technology readiness level (TRL) before they build it into a BFR. This includes the guidance system software for the LES and landing from space. SpaceX does not a BFR yet but it will soon have some used Dragon 2s to which legs can be added.

Offline kevinof

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #98 on: 01/19/2018 08:40 AM »
So let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.

What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.

Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #99 on: 01/19/2018 09:30 AM »
So let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.

What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.

Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.

This.

This is exactly why.

NASA has a very substantial database on everything involved in putting the crew on the vehicle AFTER it has been fueled.
They have NO knowledge on everything involved in putting crew on the vehicle BEFORE it is fueled.

Plain-and-simple it is this: NASA is afraid of change.

That's why NASA shot down propulsive landing for Crew Dragon: it is a radical break from the traditional way to land a capsule (parachute).

That's why SLS is basically a modern-day implementation of a 1970s-based launch vehicle design (RS-25, SRBs, external foam insulation, etc, etc.)

That is why NASA is still using the 1970's EMUs for EVAs because they don't dare completing and certifying their half dozen newer suit designs.

That is why NASA has the US Navy involved in post-landing crew-egress and recovery of Orion, in stead of using (much cheaper) commercially available assets.

That is why NASA is designing its monster rocket by itself, in stead of having the industry do it for them.

That is why the huge success of COTS/CRS model was not repeated for CCP: it upset their established way-of-doing-things too much when applied on a bigger scale.

Etc, etc, etc.

But I digress.
« Last Edit: 01/19/2018 09:32 AM by woods170 »

Offline SimonFD

So let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.

What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.

Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.

Is it not the other way around? Put the astros in an un-fueled rocket and then leave?
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Offline kevinof

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #101 on: 01/19/2018 09:35 AM »
SpaceX want to have an empty rocket, get the crew on and then fuel.

Nasa wan't to fuel first, then go back to the pad with the astros and get them onboard.



So let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.

What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.

Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.

Is it not the other way around? Put the astros in an un-fueled rocket and then leave?
« Last Edit: 01/19/2018 09:35 AM by kevinof »

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #102 on: 01/19/2018 12:36 PM »
So let me understand this. Currently, during even a static fire, they close off the pad, put up road blocks , remove everyone to a distance to 50,000 miles and then do the static fire.

What Nasa are proposing is the same process, but then stick their prized Astos and employees (and Spacex) in a bus, drive back to the pad, climb the gantry, out on the crew arm , open the hatch and get the crew seated (and if I remember from the Shuttle days this took forever) all the while standing a couple of metres away from this fully fuelled and loaded , hissing and grumbling rocket.

Are they serious? Seems to me it's lack of logic and more "we've always done it this way and therefore there is no other way" thinking.

Just stop this nonsense.  The lack of logic applies to posts like these.
 It is a common practice  to go near a fueled rocket.  See Ice teams, red teams, closeout crew, etc.   

What is not common is to be near a rocket while it is in the process of being fueled.  See Amos-5.
« Last Edit: 01/19/2018 12:37 PM by Jim »

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #103 on: 01/19/2018 12:43 PM »
Apollo had a slide wire even though it had an LES.  LES is like an ejection seat, it is the last resort, you avoid it if possible

Offline spacenut

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #104 on: 01/19/2018 12:44 PM »
Why can't SpaceX not use super cooled LOX and land the rocket on the drone ship?  Super cooling is what 12% more LOX than standard?  The Dragon II is only going to LEO.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #105 on: 01/19/2018 12:47 PM »
What is not common is to be near a rocket while it is in the process of being fueled.  See Amos-5.

That would be Amos-6. You're the second one to get this wrong. Some character at Capitol Hill recently referred to it as Amos-9.
« Last Edit: 01/19/2018 12:48 PM by woods170 »

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #106 on: 01/19/2018 12:50 PM »
Why can't SpaceX not use super cooled LOX and land the rocket on the drone ship?  Super cooling is what 12% more LOX than standard?  The Dragon II is only going to LEO.


Falcon 9 and GSE have been changed to ALWAYS use super-cooled LOX. There is no going back. Not without a costly complete reversal of earlier changes.

Offline Ugger55

Apollo had a slide wire even though it had an LES.  LES is like an ejection seat, it is the last resort, you avoid it if possible

Could a difference be due to SpaceX's preference for mechanical reusable systems over pyro systems though. Would a Dragon operating its LES damage the attached rocket. Is the LES sep a mechanical connection like they use for S1 sep and Fairing sep, and would it be quick enough for use in LES or have they gone with a pyro disconnect just for LES?

With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?

Personally I'd not like to approach a rocket "on foot" if it has fuel in it, id much rather sit in a safe system beforehand....

Online rockets4life97

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #108 on: 01/19/2018 01:25 PM »
Seems to me we have two historically rare failure modes: failure while fueling and failure while fueled in a stable state on the pad. The second has been "normalized" as it is the current practice. The true risk of each is probably unknown (and unknowable statistically due to the the problem of defining the tail of the distribution).

I'd personally risk fewer people. I put a very high price on human life. I'd take a failure risk that killed 4 people 5 times as often than one that killed 20 people in one go.

Offline kevinof

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #109 on: 01/19/2018 01:26 PM »
The reason a LAS would be activated in the first place would be that there is a big problem (ie kaboom) with the rocket. There's not going to be much left of the stack no matter what the engineering. No difference between Falcon and any other rocket.

Apollo had a slide wire even though it had an LES.  LES is like an ejection seat, it is the last resort, you avoid it if possible

Could a difference be due to SpaceX's preference for mechanical reusable systems over pyro systems though. Would a Dragon operating its LES damage the attached rocket. Is the LES sep a mechanical connection like they use for S1 sep and Fairing sep, and would it be quick enough for use in LES or have they gone with a pyro disconnect just for LES?

With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?

Personally I'd not like to approach a rocket "on foot" if it has fuel in it, id much rather sit in a safe system beforehand....

Offline Ugger55

The reason a LAS would be activated in the first place would be that there is a big problem (ie kaboom) with the rocket. There's not going to be much left of the stack no matter what the engineering. No difference between Falcon and any other rocket.

Apollo had a slide wire even though it had an LES.  LES is like an ejection seat, it is the last resort, you avoid it if possible

Could a difference be due to SpaceX's preference for mechanical reusable systems over pyro systems though. Would a Dragon operating its LES damage the attached rocket. Is the LES sep a mechanical connection like they use for S1 sep and Fairing sep, and would it be quick enough for use in LES or have they gone with a pyro disconnect just for LES?

With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?

Personally I'd not like to approach a rocket "on foot" if it has fuel in it, id much rather sit in a safe system beforehand....

Oh completely agree there in principle. Was wondering what the engineering solution being implemented would be. Was it a Gemini launch where there was a near activation of the LAS? In such a situation, were the Dragon LAS to be activated what would happen.

I'd be interested to know what other scenarios could exist (past kaboom) that in current launcher configurations use the "all launch crew leg it" egress method.

To me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, and whena fully fuelled bomb on a pad with its fuse lit (terminal count). But we don't seem to trust that system during fuelling. Instead, conventional knowledge is that tens of people will stand in elevators going up and down hundreds of feet next to this primed rocket, jumping about on people to get them in to chairs, swinging doors open and closed etc. with not a worry in the world yet none of them could escape were there to be some untelegraphed RUD 
« Last Edit: 01/19/2018 01:53 PM by Ugger55 »

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #111 on: 01/19/2018 02:31 PM »

To me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, 

It is because it is the only method available.  It is not the best or safest method when there are other available on the ground.  That is why slidewire and elevators are used.
« Last Edit: 01/19/2018 02:32 PM by Jim »

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #112 on: 01/19/2018 02:33 PM »
But we don't seem to trust that system during fuelling.

No, the rocket is not trusted and hence why put crew near it.

Steady state replenishment is not unlike the propellant tank farm while tankers are refilling the big sphere before launch. 
« Last Edit: 01/19/2018 02:36 PM by Jim »

Offline jak Kennedy

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #113 on: 01/19/2018 03:28 PM »

To me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, 

It is because it is the only method available.  It is not the best or safest method when there are other available on the ground.  That is why slidewire and elevators are used.

I think there is an assumption that it is "not the best or safest method"  Have the slidewires or elevators ever been used in an emergency? They certainly do not sound like the quickest way to get clear of a rocket. The LAS has been proved in the case of Soyuz 7K-ST 16L. Only after events happen does NASA seem to reconsider 'change'.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #114 on: 01/19/2018 04:22 PM »

I think there is an assumption that it is "not the best or safest method"  Have the slidewires or elevators ever been used in an emergency? They certainly do not sound like the quickest way to get clear of a rocket. The LAS has been proved in the case of Soyuz 7K-ST 16L. Only after events happen does NASA seem to reconsider 'change'.

That was due a fire, there are other events that don't need such a quick and injurious method.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #115 on: 01/19/2018 06:14 PM »
Nope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?
I'm not at all clear on how this is going to work. First, there's the issue of what ASAP will think of the BFR/BFS. At least so far, I'm unaware of any plan for a crew escape system, certainly not after first stage separation. That probably will not go down very well with them.

Then there is the whole question of how many total Commercial Crew launches are there going to be at all. The ISS is not going to be in orbit for very many more years, and it's not clear at all that NASA is going to replace it, nor do any BEO crewed launches other than with with the SLS is it?

I suppose space tourism may take up some launches, but I don't know what, if any, influence ASAP has on those.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #116 on: 01/19/2018 07:01 PM »
Nope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?
I'm not at all clear on how this is going to work. First, there's the issue of what ASAP will think of the BFR/BFS. At least so far, I'm unaware of any plan for a crew escape system, certainly not after first stage separation. That probably will not go down very well with them.

Then there is the whole question of how many total Commercial Crew launches are there going to be at all. The ISS is not going to be in orbit for very many more years, and it's not clear at all that NASA is going to replace it, nor do any BEO crewed launches other than with with the SLS is it?

I suppose space tourism may take up some launches, but I don't know what, if any, influence ASAP has on those.

As long as commercial companies keep NASA out (don't let NASA "run the show") ASAP will have no influence whatsoever.

ASAP is an advisory panel for NASA only.

Keep NASA out and the only agency involved is the FAA. Such as BO is doing with New Shepard and New Glenn. Blue only needs a launch license from the FAA to launch tourists on New Shepard. No permission needed from NASA (let alone ASAP) whatsoever.
« Last Edit: 01/19/2018 07:04 PM by woods170 »

Online AncientU

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #117 on: 01/19/2018 07:07 PM »
Nope. Dragon2 is not their end-game. BFR is where they want to be and why waste the money and time getting legs on a Dragon?
I'm not at all clear on how this is going to work. First, there's the issue of what ASAP will think of the BFR/BFS. At least so far, I'm unaware of any plan for a crew escape system, certainly not after first stage separation. That probably will not go down very well with them.

Then there is the whole question of how many total Commercial Crew launches are there going to be at all. The ISS is not going to be in orbit for very many more years, and it's not clear at all that NASA is going to replace it, nor do any BEO crewed launches other than with with the SLS is it?

I suppose space tourism may take up some launches, but I don't know what, if any, influence ASAP has on those.

As long as commercial companies keep NASA out (don't let NASA "run the show") ASAP will have no influence whatsoever.

ASAP is an advisory panel for NASA only.

Keep NASA out and the only agency involved is the FAA. Such as BO is doing with New Shepard and New Glenn. Blue only needs a launch license from the FAA to launch tourists on New Shepard. No permission needed from NASA (let alone ASAP) whatsoever.

Exactly.
If SpaceX ever allows NASA/ASAP to start calling shots for BFR/BFS, they haven't learned their lesson.

NASA can fly their astros after signing the disclosure statement like everyone else that fly these vehicles.
"If we shared everything [we are working on] people would think we are insane!"
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Offline rayleighscatter

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #118 on: 01/19/2018 08:46 PM »

To me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, 

It is because it is the only method available.  It is not the best or safest method when there are other available on the ground.  That is why slidewire and elevators are used.

I think there is an assumption that it is "not the best or safest method"  Have the slidewires or elevators ever been used in an emergency? They certainly do not sound like the quickest way to get clear of a rocket. The LAS has been proved in the case of Soyuz 7K-ST 16L. Only after events happen does NASA seem to reconsider 'change'.

You can't prove the safety of something simply by doing it. 5 out of 6 people would tell you russian roulette is perfectly safe.  You have to understand the system as best as reasonably possible.

There are still many many concerns over any form of LAS. For instance, nearly all of them trust parachutes in an environment that includes several tons of rapidly propagating shrapnel.

Offline Space Ghost 1962

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #119 on: 01/19/2018 08:48 PM »
Point out two things.

First, HSF is peculiar due to history, politics, and global influence / "soft power" - that means running a rather severe gauntlet to begin with.

Second, when you've run that gauntlet, it has an enduring value. It is possible for those who have done so to be further considered for other missions later.

And while it's especially true that the first doesn't imply the second, especially in this "post truth, fake everything you don't like" world, there are definite consequences to ignoring the linking of the two.

(As there was to using private "cheap" security force to back up actual military personnel last year, leaving a man behind.)

It's infuriating watching this drama without reasonable transparency on actual, underlying issues. The last thing you want is a clear and objective closeout of issues interrupted by obscure and possibly irrelevant/dilatory items added to a program as its gearing up for first flights. Which seems to be happening.

Assuming Dragon 2 still flies its demo missions, not only does it place the burden on NASA (and ASAP) on wrestling with the political demons as to CC missions, it also captures the fact that the process has arrived at a reasonable conclusion, and can be used as a model for BFS (and perhaps later BO capsules).

(One should also realize that many will later study both CC and CRS programs in detail, and no doubt the "heavy hand" of certain influences will be revealed as to be the chief obstacle/inhibitor to cost/time. Expect also this will inform on certain Orion lossage as well in like manner.)

Offline Steven Pietrobon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #120 on: 01/20/2018 04:45 AM »
Why can't SpaceX not use super cooled LOX and land the rocket on the drone ship?  Super cooling is what 12% more LOX than standard?  The Dragon II is only going to LEO.

My calculations showed a 9.8% increase in LOX density. RP-1 density increases by 2.6%. Having to use NBP LOX would mean SpaceX would have to requalify their engines for the higher temperature propellants as well as then having seven flights with the corresponding loss of performance.

With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?

If the LES has to be activated, its because the vehicle is about to go kablooey.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Online Johnnyhinbos

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #121 on: 01/20/2018 05:49 AM »
When NASA apply the 1/270 and seven flights criteria* to SLS with Orion, I'll start listening to this nonsense.
Until then, it is just bureaucratic spinelessness.

* Oh, and add no turbo blade cracking on RS-25s...

I’ve been wondering about this - and perhaps this is now thread misplaced- but why doesn’t the “seven flight prior flight history before flying crew” criteria apply to SLS? I know it’s based on a few flight experienced components, but it’s still an unknown rocket.

And why doesn’t the turbo cracking concern apply to its engines (I recall reading a rather lengthy report, I think by AR, on the issues with the RS-25  and on suggested modifications that never were implemented).

That ASAP / NASA doesn’t apply the same criteria mystifies me (and I’m trying to keep politics out of this, though perhaps it’s impossible).
John Hanzl. Author, action / adventure www.johnhanzl.com

Offline deruch

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #122 on: 01/20/2018 06:10 AM »
That is why the huge success of COTS/CRS model was not repeated for CCP: it upset their established way-of-doing-things too much when applied on a bigger scale.

COTS model of using SAAs instead of contracts wasn't repeated for CCP because it wouldn't allow NASA to dictate any changes due to the limitations of SAAs.  Which would mean that the providers might develop systems that NASA would never agree to use for crew rotations.  Without NASA as an anchor client spending that amount of money to develop a HSF vehicle isn't reasonable.
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline joek

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #123 on: 01/20/2018 06:55 AM »
That is why the huge success of COTS/CRS model was not repeated for CCP: it upset their established way-of-doing-things too much when applied on a bigger scale.

COTS model of using SAAs instead of contracts wasn't repeated for CCP because it wouldn't allow NASA to dictate any changes due to the limitations of SAAs.  Which would mean that the providers might develop systems that NASA would never agree to use for crew rotations.  Without NASA as an anchor client spending that amount of money to develop a HSF vehicle isn't reasonable.

Appears much of this discussion is due to a misunderstanding of how and when OTA (Other Transaction Authority) as used for SAA's can be applied (e.g., COTS, CCxCap) vs. FAR acquisition rules (e.g, CRS, CCtCap).

There are specific rules that NASA must abide by, and the NASA IG concurred that the current approach is consistent with Congressional direction and law.  Ask yourself why CRS required a FAR contract vs. COTS which was executed under an SAA.

If you understand the what and why, great.  If not, go fish.  You don't like the rules?  Write a letter to your Congress-critter.  In any case, stop whining about it.


Offline su27k

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #124 on: 01/20/2018 07:26 AM »
That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.
Wrong, static fires fully fuel the vehicle, and every launch has been preceded by a static fire.  The originally cited 38 is correct.

Actually it's even higher than that since there're at least 4 last minute aborts (Intelsat 35e had two in a row), total is more like 42.

Offline obi-wan

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #125 on: 01/20/2018 06:17 PM »
With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?

If the LES has to be activated, its because the vehicle is about to go kablooey.
It's an interesting point, though - Starliner, with its abort engines inside the service module, are doing a "fire in the hole" abort that would almost certainly blow out the upper dome of the Centaur LH2 tank and initiate a conflagration, regardless of the prior state of the vehicle. Dragon, like the NASA launch abort system tractor rockets, cants the thrust outboard, so there's no direct plume impact to the launch vehicle. It's not beyond the realm of possibility that the F9 would still be usable following an inadvertent abort.

Offline butters

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #126 on: 01/20/2018 06:36 PM »
Assuming Dragon 2 still flies its demo missions, not only does it place the burden on NASA (and ASAP) on wrestling with the political demons as to CC missions, it also captures the fact that the process has arrived at a reasonable conclusion, and can be used as a model for BFS (and perhaps later BO capsules).

SpaceX has learned their lesson, and Blue Origin is paying attention. They will embrace FAA regulation for all future human spacecraft and invite NASA to purchase transportation services if they so choose. But they're never going to develop a spacecraft to NASA requirements ever again. The money is not worth the strings attached.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #127 on: 01/20/2018 06:51 PM »
Assuming Dragon 2 still flies its demo missions, not only does it place the burden on NASA (and ASAP) on wrestling with the political demons as to CC missions, it also captures the fact that the process has arrived at a reasonable conclusion, and can be used as a model for BFS (and perhaps later BO capsules).

SpaceX has learned their lesson, and Blue Origin is paying attention. They will embrace FAA regulation for all future human spacecraft and invite NASA to purchase transportation services if they so choose. But they're never going to develop a spacecraft to NASA requirements ever again. The money is not worth the strings attached.

Indeed. It is the very reason why it was so difficult to figure out HOW to fund BFS/BFR. You don't want NASA involved, because they will muck things up (again) but that also means you don't get NASA funding.

But I think in this case the advantages outweigh the disadvantages.

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #128 on: 01/21/2018 05:16 PM »
With Apollo, LES activation on a stable stack would, I imagine render the stack unusable at best, destroy it at worst. Is this likely true for Falcon too?

If the LES has to be activated, its because the vehicle is about to go kablooey.
It's an interesting point, though - Starliner, with its abort engines inside the service module,

No, the abort engines are on the outside

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #129 on: 01/21/2018 05:23 PM »
Seems to me we have two historically rare failure modes: failure while fueling and failure while fueled in a stable state on the pad. The second has been "normalized" as it is the current practice. The true risk of each is probably unknown (and unknowable statistically due to the the problem of defining the tail of the distribution).

I'd personally risk fewer people. I put a very high price on human life. I'd take a failure risk that killed 4 people 5 times as often than one that killed 20 people in one go.

That would stupid and worse because after the first of 5 times, you are making people go back into a known riskier situation.

Online rockets4life97

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #130 on: 01/21/2018 05:24 PM »
Seems to me we have two historically rare failure modes: failure while fueling and failure while fueled in a stable state on the pad. The second has been "normalized" as it is the current practice. The true risk of each is probably unknown (and unknowable statistically due to the the problem of defining the tail of the distribution).

I'd personally risk fewer people. I put a very high price on human life. I'd take a failure risk that killed 4 people 5 times as often than one that killed 20 people in one go.

That would stupid and worse because after the first of 5 times, you are making people go back into a known riskier situation.

Thanks for taking the bait. Yes! So if 4 people were ever killed 1 one time. You can guarantee there will be an extensive investigation and a fix. Much better than 20 people dying!

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #131 on: 01/21/2018 05:26 PM »
Seems to me we have two historically rare failure modes: failure while fueling and failure while fueled in a stable state on the pad. The second has been "normalized" as it is the current practice. The true risk of each is probably unknown (and unknowable statistically due to the the problem of defining the tail of the distribution).

I'd personally risk fewer people. I put a very high price on human life. I'd take a failure risk that killed 4 people 5 times as often than one that killed 20 people in one go.

That would stupid and worse because after the first of 5 times, you are making people go back into a known riskier situation.

Thanks for taking the bait. Yes! So if 4 people were ever killed 1 one time. You can guarantee there will be an extensive investigation and a fix. Much better than 20 people dying!

20 people aren't going to die in the first place because it is safer because the same issue would have happened and no people would be around it.
« Last Edit: 01/21/2018 05:28 PM by Jim »

Offline deruch

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #132 on: 01/21/2018 05:50 PM »
That is why the huge success of COTS/CRS model was not repeated for CCP: it upset their established way-of-doing-things too much when applied on a bigger scale.

COTS model of using SAAs instead of contracts wasn't repeated for CCP because it wouldn't allow NASA to dictate any changes due to the limitations of SAAs.  Which would mean that the providers might develop systems that NASA would never agree to use for crew rotations.  Without NASA as an anchor client spending that amount of money to develop a HSF vehicle isn't reasonable.

Appears much of this discussion is due to a misunderstanding of how and when OTA (Other Transaction Authority) as used for SAA's can be applied (e.g., COTS, CCxCap) vs. FAR acquisition rules (e.g, CRS, CCtCap).

There are specific rules that NASA must abide by, and the NASA IG concurred that the current approach is consistent with Congressional direction and law.  Ask yourself why CRS required a FAR contract vs. COTS which was executed under an SAA.

If you understand the what and why, great.  If not, go fish.  You don't like the rules?  Write a letter to your Congress-critter.  In any case, stop whining about it.

Don't be obtuse.  NASA could certainly have structured CCtCap such that it could be executed under OTA instead of FAR rules.  But, it would have limited the scope of the agreements to strictly generic development without providing utility to the agency and it would have eliminated their ability to set requirements narrowly to meet their specific needs (present or future).  So, they couldn't have used it for anything after the crewed demonstrations, which likely wouldn't have had NASA astronauts flying on them.  After that point, there would have been a contract under FAR rules for modifications, certification, and any post-certification missions.  A bit clunky, and potentially high financial risk to the providers.  But, it was certainly an available option.  It would have been perfectly equivalent to COTS in that respect which needed the follow-on FAR contract of CRS to allow NASA to actually get use from the developed vehicles.  There were plenty of reasons for NASA not liking that approach but their inability to direct and enforce changes to the capsules (via setting performance requirements) was seen as unacceptable for HSF. 
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #133 on: 01/22/2018 06:13 AM »

To me, it just feels wrong that we trust a LAS to work on a rocket when it is flying, subsonic, transonic, supersonic, at Max-Q, 

It is because it is the only method available.  It is not the best or safest method when there are other available on the ground.  That is why slidewire and elevators are used.

I think there is an assumption that it is "not the best or safest method"  Have the slidewires or elevators ever been used in an emergency? They certainly do not sound like the quickest way to get clear of a rocket. The LAS has been proved in the case of Soyuz 7K-ST 16L. Only after events happen does NASA seem to reconsider 'change'.

You can't prove the safety of something simply by doing it. 5 out of 6 people would tell you russian roulette is perfectly safe.  You have to understand the system as best as reasonably possible.

There are still many many concerns over any form of LAS. For instance, nearly all of them trust parachutes in an environment that includes several tons of rapidly propagating shrapnel.

That is primarily a concern for pad aborts/near ground aborts only given that only those low-level altitude aborts require fast deployment of the parachutes.
Point is however that LAS is designed to carry the capsule to well above and out of any propagating shrapnel cloud.
The parachute concern is mainly an academic one because some folks are overly concerned that in the most unlikely of all shrapnel-propagation scenario's one-or-more parachutes might be holed by shrapnel.

Well, AMOS-6 has provided us with nice, hard, data-points. The SpaceX pad abort scenario has been super-imposed over the catastrophic AMOS-6 explosion (and I don't mean the YouTube home-made versions, but the special-studies investigation done by NASA and SpaceX, under CCtCAP, in the wake of AMOS-6).

And guess what: the propagation of shrapnel never even got close to the under-parachute portion of the pad abort trajectory. Which is a clear data-point that the design of the LAS (to carry the capsule sufficiently far away from the kaboom) is sound. And mind you: hard data beats academic exercise.
« Last Edit: 01/22/2018 06:15 AM by woods170 »

Offline whatever11235

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #134 on: 01/22/2018 07:47 AM »


Can you please expand on this? Why are rules not the same? As I understand it, NASA is collaborating heavily with SpaceX on Dragon2 design. How is it different with regards to their vendors for SLS/Orion?
« Last Edit: 01/23/2018 01:49 PM by Chris Bergin »

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #135 on: 01/22/2018 09:59 AM »
I'll pick this one up for Jim given that he has answered this very question many, many times, and people still keep asking the question.

Basically:
On Orion and SLS NASA runs the show entirely, down the smallest little details. They are involved in everything and the contractors don't do anything without NASA permission. For example: NASA tells Boeing: go build SLS with a core stage driven by four RS-25s and boosted by two 5-segment ATK SRBs using the design you'll find in your mailbox".

On CCP NASA sets high-level *cough* requirements and basically tells the contractors: "Realize those requirements the way you see fit. Just as long as your solutions meet the requirements".
For example: NASA tells Boeing: go do your thing as long as it gets us a service that can transport 4 astronauts to the ISS.
NASA than engages in insight and oversight into what the contractors do. But the solutions are conceived, developed, integrated and tested by the contractors and are not the brainchild of NASA.
And exactly for this reason does NASA not automatically trust the contractor's solutions. Those solutions need to prove themselves. And that's why - for example - Falcon 9 Block 5 needs to fly at least seven times before it can launch crew. It is also why - for example - the contractors will have to prove that they meet the 1-in-270 LOC requirement.

Naturally, NASA will trust its own design for SLS with just one unmanned test-flight but not trust someone else's design until it has flown seven times.

That's it. Plain and simple. Don't like it? Too bad, because this is the reality for SLS/Orion vs. CCP. And it is not going to change.
« Last Edit: 01/23/2018 01:48 PM by Chris Bergin »

Offline mn

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #136 on: 01/22/2018 12:48 PM »


Please clarify:

Does this mean that their design doesn't need to meet the 1/270 requirement?

Or because they designed it they are confident that it does indeed meet that requirement?
« Last Edit: 01/23/2018 01:49 PM by Chris Bergin »

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #137 on: 01/22/2018 01:17 PM »
I'll pick this one up for Jim given that he has answered this very question many, many times, and people still keep asking the question.

Basically:
On Orion and SLS NASA runs the show entirely, down the smallest little details. They are involved in everything and the contractors don't do anything without NASA permission. For example: NASA tells Boeing: go build SLS with a core stage driven by four RS-25s and boosted by two 5-segment ATK SRBs using the design you'll find in your mailbox".

On CCP NASA sets high-level *cough* requirements and basically tells the contractors: "Realize those requirements the way you see fit. Just as long as your solutions meet the requirements".
For example: NASA tells Boeing: go do your thing as long as it gets us a service that can transport 4 astronauts to the ISS.
NASA than engages in insight and oversight into what the contractors do. But the solutions are conceived, developed, integrated and tested by the contractors and are not the brainchild of NASA.
And exactly for this reason does NASA not automatically trust the contractor's solutions. Those solutions need to prove themselves. And that's why - for example - Falcon 9 Block 5 needs to fly at least seven times before it can launch crew. It is also why - for example - the contractors will have to prove that they meet the 1-in-270 LOC requirement.

Naturally, NASA will trust its own design for SLS with just one unmanned test-flight but not trust someone else's design until it has flown seven times.

That's it. Plain and simple. Don't like it? Too bad, because this is the reality for SLS/Orion vs. CCP. And it is not going to change.

Please clarify:

Does this mean that their design doesn't need to meet the 1/270 requirement?

Or because they designed it they are confident that it does indeed meet that requirement?

If SLS/Orion would be flying the same mission profile (crew to ISS) than IMO it would have to meet the 1/270 requirement.
However, SLS/Orion is not intended for Crew-to-ISS missions. The LOC/LOM numbers for the SLS/Orion combo are different (and, as far as I know) not generally known to the public.

And yes: because NASA designed its own vehicles and "runs the show" for its own vehicles NASA is confident its own vehicles will meet its own requirements. One clear indicator to this is that ASAP has been reporting on the CCP LOC numbers for years now but hasn't spent a single word, on the LOC numbers for SLS/Orion, in their reporting.
« Last Edit: 01/22/2018 01:18 PM by woods170 »

Offline mn

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #138 on: 01/22/2018 01:18 PM »


And I should add that I think there is nothing wrong with stating that SLS is a different type of mission and we accept a higher risk for those missions
« Last Edit: 01/23/2018 01:49 PM by Chris Bergin »

Online scdavis

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #139 on: 01/22/2018 04:45 PM »
And yes: because NASA designed its own vehicles and "runs the show" for its own vehicles NASA is confident its own vehicles will meet its own requirements. One clear indicator to this is that ASAP has been reporting on the CCP LOC numbers for years now but hasn't spent a single word, on the LOC numbers for SLS/Orion, in their reporting.

This makes perfect sense, understandable on a human and organizational level. NASA trusts its own engineers and processes -- outside organizations somewhat less. The more the external company's design and process differs from NASA, the more they want to validate independently.

A question from some outside of NASA, including some on this forum, is whether NASA is putting the correct level of trust in their internal work and the right amount of skepticism on external work.

Points in favor of NASA trusting self/skeptical of external designs:
* Have run human spaceflight programs for decades
* Responsible for primary design of multiple HSF vehicles

Points against:
* LOC incidents on shuttle suggests shouldn't trust self so highly.
* Placing crew on only second lift off of SLS. Really? Suggests acceptance of huge risk on in-house design. [1]
* Tales from insiders and outsiders of stifling bureaucracy.
* Haven't designed a new HSF vehicle in decades until SLS/Orion.
* The HSF project they *are* leading as chief designer is monstrously expensive and late. We can blame Congress all we want, but in the end NASA is responsible.

Given this open question, when NASA chooses to put crew on the second flight of SLS while requiring Boeing and SpaceX to prove a very high level of reliability, it looks like bias. [1]

As the customer, of course NASA can require whatever they want of their vendor. But as a citizen served by NASA, I'd like to see our space agency make optimum use of its internal and external talent. Maybe they are doing exactly that -- the evidence is hard to see. Or perhaps it's more fair to say: a large ship turns slowly.

[1] Granting: SLS/Orion so terrifically expensive to fly that they cannot choose otherwise.

Online envy887

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #140 on: 01/22/2018 05:20 PM »
It is a common practice  to go near a fueled rocket.  See Ice teams, red teams, closeout crew, etc.   

It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

Offline Ronsmytheiii

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #141 on: 01/22/2018 06:54 PM »
It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

There isnt a need to currently, but once crew flies on CST-100 Starliner, they will to support the crew. Comparing a manned and unmanned launch is pretty much apples and oranges.

Edit: And the Russians also have crew near a loaded Soyuz for manned flights.
« Last Edit: 01/22/2018 07:11 PM by Ronsmytheiii »
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Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #142 on: 01/22/2018 07:53 PM »
It is a common practice  to go near a fueled rocket.  See Ice teams, red teams, closeout crew, etc.   

It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

Yes, every launch vehicle contractor has a crew that is set up to go near a fueled launch vehicle for troubleshooting.  It is not a rare event.
« Last Edit: 01/22/2018 07:55 PM by Jim »

Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #143 on: 01/22/2018 07:54 PM »
It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

There isnt a need to currently, but once crew flies on CST-100 Starliner, they will to support the crew. Comparing a manned and unmanned launch is pretty much apples and oranges.

Edit: And the Russians also have crew near a loaded Soyuz for manned flights.

More than just flight and support crew, but scores of well wishers.
« Last Edit: 01/22/2018 07:55 PM by Jim »

Offline Martin.cz

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #144 on: 01/22/2018 07:55 PM »
For the record - you can see people running around a fully fuelled rocket a few minutes before launch on many Soyuz launch brodcasts.

EDIT: too late :D

Also thinking about it, Shenzhou is likely the same - IIRC you can seen the ground crew leave also quite late, so unless the fueling is really quick, the rocket is fully fueled with hypergolics at that time. On the other hand, they don't have any boiloff so they might do remote tanking, check for any leaks and only then let the crew and ground crew aproach the rocket.
« Last Edit: 01/22/2018 07:56 PM by Martin.cz »

Online rockets4life97

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #145 on: 01/22/2018 07:57 PM »
It is a common practice  to go near a fueled rocket.  See Ice teams, red teams, closeout crew, etc.   

It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

Every launch vehicle contractor has a crew that is set up to go near a fueled launch vehicle for troubleshooting.  It is not a rare event.

Except SpaceX I presume?

I'm looking forward to a few years from now, when SpaceX has more flight history than ULA.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #146 on: 01/22/2018 08:01 PM »
It is a common practice  to go near a fueled rocket.  See Ice teams, red teams, closeout crew, etc.   

It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

Every launch vehicle contractor has a crew that is set up to go near a fueled launch vehicle for troubleshooting.  It is not a rare event.

Except SpaceX I presume?
 

Nope, they too have one

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #147 on: 01/22/2018 08:06 PM »
I'll pick this one up for Jim given that he has answered this very question many, many times, and people still keep asking the question.

Basically:
On Orion and SLS NASA runs the show entirely, down the smallest little details. They are involved in everything and the contractors don't do anything without NASA permission. For example: NASA tells Boeing: go build SLS with a core stage driven by four RS-25s and boosted by two 5-segment ATK SRBs using the design you'll find in your mailbox".

On CCP NASA sets high-level *cough* requirements and basically tells the contractors: "Realize those requirements the way you see fit. Just as long as your solutions meet the requirements".
For example: NASA tells Boeing: go do your thing as long as it gets us a service that can transport 4 astronauts to the ISS.
NASA than engages in insight and oversight into what the contractors do. But the solutions are conceived, developed, integrated and tested by the contractors and are not the brainchild of NASA.
And exactly for this reason does NASA not automatically trust the contractor's solutions. Those solutions need to prove themselves. And that's why - for example - Falcon 9 Block 5 needs to fly at least seven times before it can launch crew. It is also why - for example - the contractors will have to prove that they meet the 1-in-270 LOC requirement.

Naturally, NASA will trust its own design for SLS with just one unmanned test-flight but not trust someone else's design until it has flown seven times.

That's it. Plain and simple. Don't like it? Too bad, because this is the reality for SLS/Orion vs. CCP. And it is not going to change.

Please clarify:

Does this mean that their design doesn't need to meet the 1/270 requirement?

Or because they designed it they are confident that it does indeed meet that requirement?

If SLS/Orion would be flying the same mission profile (crew to ISS) than IMO it would have to meet the 1/270 requirement.
However, SLS/Orion is not intended for Crew-to-ISS missions. The LOC/LOM numbers for the SLS/Orion combo are different (and, as far as I know) not generally known to the public.

And yes: because NASA designed its own vehicles and "runs the show" for its own vehicles NASA is confident its own vehicles will meet its own requirements. One clear indicator to this is that ASAP has been reporting on the CCP LOC numbers for years now but hasn't spent a single word, on the LOC numbers for SLS/Orion, in their reporting.
Not meaning to fan the flames of debate between NASA design and commercial design safety, but I think it’s important to ask when was the last time NASA designed and (oversaw) built a human rated spacecraft system? It’s a perishable skill that’s perished on many fronts. Look at the TPS for an example. The NASA TPS team actually had to visit museums to study the Apollo capsule and basically reverse engineer the shield. And they then discovered they were rediscovering issues the Apollo engineers encountered 50 years ago. Just because NASA has their hands on the wrench doesn’t mean the bolt they’re tightening is the proper one... (<— not even sure I get that analogy).

John Hanzl. Author, action / adventure www.johnhanzl.com

Offline whatever11235

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #148 on: 01/22/2018 09:33 PM »
... The NASA TPS team actually had to visit museums to study the Apollo capsule and basically reverse engineer the shield. And they then discovered they were rediscovering issues the Apollo engineers encountered 50 years ago.
...

Can you please provide links with more details? Sounds like an interesting story.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #149 on: 01/22/2018 10:12 PM »
... The NASA TPS team actually had to visit museums to study the Apollo capsule and basically reverse engineer the shield. And they then discovered they were rediscovering issues the Apollo engineers encountered 50 years ago.
...

Can you please provide links with more details? Sounds like an interesting story.
Here's a really interesting presentation by Jeremy Vander Kam given at the Ames Research Center in 2015. He's well spoken, intelligent, and the material was really interesting.

"Burn to Shine: Experiences and Lessons from the Orion Heat Shield"



I highly recommend watching it...
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #150 on: 01/22/2018 10:40 PM »
Here's a really interesting presentation by Jeremy Vander Kam given at the Ames Research Center in 2015. He's well spoken, intelligent, and the material was really interesting.

"Burn to Shine: Experiences and Lessons from the Orion Heat Shield"



I highly recommend watching it...

No doubt very interesting. I did notice though that they have a misspelling on the title slide:

"...Lessons From the Orion Heath Shield" - should be "Heat", not "Heath".

Rocket scientists...   :o
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #151 on: 01/23/2018 01:34 AM »
{snip}
Can you please expand on this? Why are rules not the same? As I understand it, NASA is collaborating heavily with SpaceX on Dragon2 design. How is it different with regards to their vendors for SLS/Orion?

I'll pick this one up for Jim given that he has answered this very question many, many times, and people still keep asking the question.

Basically:
On Orion and SLS NASA runs the show entirely, down the smallest little details. They are involved in everything and the contractors don't do anything without NASA permission. For example: NASA tells Boeing: go build SLS with a core stage driven by four RS-25s and boosted by two 5-segment ATK SRBs using the design you'll find in your mailbox".

On CCP NASA sets high-level *cough* requirements and basically tells the contractors: "Realize those requirements the way you see fit. Just as long as your solutions meet the requirements".
For example: NASA tells Boeing: go do your thing as long as it gets us a service that can transport 4 astronauts to the ISS.
NASA than engages in insight and oversight into what the contractors do. But the solutions are conceived, developed, integrated and tested by the contractors and are not the brainchild of NASA.
And exactly for this reason does NASA not automatically trust the contractor's solutions. Those solutions need to prove themselves. And that's why - for example - Falcon 9 Block 5 needs to fly at least seven times before it can launch crew. It is also why - for example - the contractors will have to prove that they meet the 1-in-270 LOC requirement.

Naturally, NASA will trust its own design for SLS with just one unmanned test-flight but not trust someone else's design until it has flown seven times.

That's it. Plain and simple. Don't like it? Too bad, because this is the reality for SLS/Orion vs. CCP. And it is not going to change.

When dealing with quality and safety standards it is irrelevant whether you do something yourself or someone else does it. The same quality standard applies. The SLS's main requirements document should specify its LOC and LOM requirements.

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.

The SLS having multiple mission types means that instead of having a single LOC it requirements should contain a table of LOCs and LOMs.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #152 on: 01/23/2018 07:15 AM »
When dealing with quality and safety standards it is irrelevant whether you do something yourself or someone else does it. The same quality standard applies. The SLS's main requirements document should specify its LOC and LOM requirements.

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.

The SLS having multiple mission types means that instead of having a single LOC it requirements should contain a table of LOCs and LOMs.

Let me put it this way: when was the last time NASA had to explain something to itself?

Answer: Challenger and Columbia.


Additionally: notice the bolded statement above? Well, NASA doesn't agree with it, because they don't require their own vehicle (SLS) to launch unmanned seven times before they put a crewed vehicle on top of it.
It is plain and simple: SLS is a NASA vehicle. As such they DO NOT apply the same standards to SLS, that they apply to a vehicle built by someone else.
« Last Edit: 01/23/2018 07:19 AM by woods170 »

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #153 on: 01/23/2018 08:57 AM »
When dealing with quality and safety standards it is irrelevant whether you do something yourself or someone else does it. The same quality standard applies. The SLS's main requirements document should specify its LOC and LOM requirements.

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.

The SLS having multiple mission types means that instead of having a single LOC it requirements should contain a table of LOCs and LOMs.

Let me put it this way: when was the last time NASA had to explain something to itself?

Answer: Challenger and Columbia.


Additionally: notice the bolded statement above? Well, NASA doesn't agree with it, because they don't require their own vehicle (SLS) to launch unmanned seven times before they put a crewed vehicle on top of it.
It is plain and simple: SLS is a NASA vehicle. As such they DO NOT apply the same standards to SLS, that they apply to a vehicle built by someone else.

Either SLS will get cancelled or NASA will get caught.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #154 on: 01/23/2018 11:08 AM »
When dealing with quality and safety standards it is irrelevant whether you do something yourself or someone else does it. The same quality standard applies. The SLS's main requirements document should specify its LOC and LOM requirements.

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.

The SLS having multiple mission types means that instead of having a single LOC it requirements should contain a table of LOCs and LOMs.

Let me put it this way: when was the last time NASA had to explain something to itself?

Answer: Challenger and Columbia.


Additionally: notice the bolded statement above? Well, NASA doesn't agree with it, because they don't require their own vehicle (SLS) to launch unmanned seven times before they put a crewed vehicle on top of it.
It is plain and simple: SLS is a NASA vehicle. As such they DO NOT apply the same standards to SLS, that they apply to a vehicle built by someone else.

Either SLS will get cancelled or NASA will get caught.

Let's just hope it is the former because the only way NASA will get caught is when a catastrophic failure of SLS happens.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #155 on: 01/23/2018 01:04 PM »


Either SLS will get cancelled or NASA will get caught.

Nonsense.  Caught?   That applies that there is a law being broke. 
Wrong. There is nothing to be caught. 

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #156 on: 01/23/2018 01:05 PM »

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.


wrong.  It doesn't have to  and congress has no say


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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #157 on: 01/23/2018 01:18 PM »


Either SLS will get cancelled or NASA will get caught.

Nonsense.  Caught?   That applies that there is a law being broke. 
Wrong. There is nothing to be caught. 

Law of nature. As Woods170 has pointed out that means a catastrophic failure.

Congress is specifying the SLS's high level requirements. It can add LOC and LOM to maximum payload mass.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #158 on: 01/23/2018 01:28 PM »

Congress is specifying the SLS's high level requirements. It can add LOC and LOM to maximum payload mass.

Congress is not going to do that.

This whole line of thinking is stupid. 
NASA is going to do as it has done in the past.  It has different rules for in house vs outside managed systems.
« Last Edit: 01/23/2018 01:30 PM by Jim »

Offline abaddon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #159 on: 01/23/2018 01:41 PM »
I know it's fun to drag SLS into ... well, everything, but maybe we can bring the focus back to Commercial Crew here?

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #160 on: 01/23/2018 01:44 PM »
When dealing with quality and safety standards it is irrelevant whether you do something yourself or someone else does it. The same quality standard applies. The SLS's main requirements document should specify its LOC and LOM requirements.

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.

The SLS having multiple mission types means that instead of having a single LOC it requirements should contain a table of LOCs and LOMs.

Let me put it this way: when was the last time NASA had to explain something to itself?

Answer: Challenger and Columbia.


Additionally: notice the bolded statement above? Well, NASA doesn't agree with it, because they don't require their own vehicle (SLS) to launch unmanned seven times before they put a crewed vehicle on top of it.
It is plain and simple: SLS is a NASA vehicle. As such they DO NOT apply the same standards to SLS, that they apply to a vehicle built by someone else.

Exactly.
This is based on the premise that NASA knows what it is doing in rocketry... see? ::)
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline DarkenedOne

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #161 on: 01/23/2018 05:05 PM »
1.  CCDev is competing with Soyuz, SLS is not  - The CCDev vehicles are there to replace the Soyuz for routine access to LEO.  It is reasonable that NASA would want the vehicles to be at least as safe as the Soyuz, which has a demonstrated LOC of better than 1:100. 

2.  CCDev launch rate is much higher, therefore it needs to be safer.  The CCDev vehicles are expected to have a launch rate of about 4 per year were as SLS will likely have 1 or less.   Over a 5 year period the CCDev vehicles will fly 20 times.  If we assume a 1/50 LOC per mission that translates into a 1/3 chance of having a LOC event in those 5 years.  Since the flight rate for SLS is so low it can get by with a 1/15 LOC per mission, and still have a lower probability of LOC over that same time period. 

3.  Everyone knows LOC and LOM estimates are just SWAGs anyway.  They have proved to be wildly off in the past.  I do not believe anyone takes them at face value.  The main value in performing the analyst that generates these estimates is that it help identify components in the launch systems that pose the highest risk. 

Offline abaddon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #162 on: 01/23/2018 05:27 PM »
2.  CCDev launch rate is much higher, therefore it needs to be safer.  The CCDev vehicles are expected to have a launch rate of about 4 per year were as SLS will likely have 1 or less.
Incorrect.  CCDev LVs will launch far more than four times per year.  SpaceX launched 18 times last year.  Atlas V launched what, 8-10?  Both LVs will launch far more frequently than SLS.  The fact that the LVs launch far more frequently than SLS on non-crewed missions improves safety in a way that SLS, without any tangible launches that are not crewed, does not benefit from.

If you want to talk capsules, Dragon 2 and CST will launch more frequently than Orion, true.  But that's only part of the equation.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #163 on: 01/23/2018 10:24 PM »
...
Atlas V launched what, 8-10?  ...

6
"If we shared everything [we are working on] people would think we are insane!"
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Offline Jim

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #164 on: 01/23/2018 10:30 PM »
When dealing with quality and safety standards it is irrelevant whether you do something yourself or someone else does it. The same quality standard applies. The SLS's main requirements document should specify its LOC and LOM requirements.

A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.

The SLS having multiple mission types means that instead of having a single LOC it requirements should contain a table of LOCs and LOMs.

Let me put it this way: when was the last time NASA had to explain something to itself?

Answer: Challenger and Columbia.


Additionally: notice the bolded statement above? Well, NASA doesn't agree with it, because they don't require their own vehicle (SLS) to launch unmanned seven times before they put a crewed vehicle on top of it.
It is plain and simple: SLS is a NASA vehicle. As such they DO NOT apply the same standards to SLS, that they apply to a vehicle built by someone else.

Exactly.
This is based on the premise that NASA knows what it is doing in rocketry... see? ::)

And it does.
https://www.nasa.gov/missions

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #165 on: 01/23/2018 10:31 PM »
...
Atlas V launched what, 8-10?  ...

6

A needless post.  6, 8 or 10 doesn't matter for the purpose of this discussion

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #166 on: 01/24/2018 12:57 AM »
This is based on the premise that NASA knows what it is doing in rocketry... see? ::)

And it does.
https://www.nasa.gov/missions
Orbital rocketry is not spacecraft design, these are completely different things.

Also, any credibility NASA had for doing orbital rockets and analyzing their safety was shot when their response to putting crew on the first launch of a brand new rocket was anything other than "No, the risk is too high, it would be unethical to seriously consider that, if you insist, we can do some analysis to prove that."

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #167 on: 01/24/2018 01:12 AM »

Orbital rocketry is not spacecraft design, these are completely different things.


Anything with rockets is rocketry.  Orbital doesn't mean anything different, same principles apply across the spectrum of missions.

As for credibility being shot, the same applies companies that do static fires with a spacecraft attached.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #168 on: 01/24/2018 02:18 AM »
As for credibility being shot, the same applies companies that do static fires with a spacecraft attached.

No, that is progress. Doing something new based on prior positive experience and risk analysis. When there is a failure, analyze it, learn from it, re-do risk analysis, take corrective action, continue with an improved design. Far different from putting people on the first flight of a brand new craft.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #169 on: 01/24/2018 03:11 AM »
I gave up on NASA risk analysis when they made the tortured claim that Ares I would be safer than an EELV.

Ridiculous.


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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #170 on: 01/24/2018 03:49 AM »
Yeah-
Looking at manned flights since 1961, and Genesis I and II, as my 3 year old daughter would say- "I no like" their LOC estimates.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #171 on: 01/24/2018 10:48 AM »

Orbital rocketry is not spacecraft design, these are completely different things.


Anything with rockets is rocketry.  Orbital doesn't mean anything different, same principles apply across the spectrum of missions.

As for credibility being shot, the same applies companies that do static fires with a spacecraft attached.

Accidents happen. What's important is to learn from them and not do them again. Thus no more spacecraft on static fires.

NASA very nearly lost a crew on STS-1. Excusable as remote/autonomous control wasn't nearly as established as it is nowadays, different time and acceptance of risks, etc. But 30 odd years later those things have changed and they are/were looking at crew on EM-1 !

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #172 on: 01/24/2018 11:18 AM »

Orbital rocketry is not spacecraft design, these are completely different things.


Anything with rockets is rocketry.  Orbital doesn't mean anything different, same principles apply across the spectrum of missions.

As for credibility being shot, the same applies companies that do static fires with a spacecraft attached.

Accidents happen. What's important is to learn from them and not do them again. Thus no more spacecraft on static fires.

NASA very nearly lost a crew on STS-1. Excusable as remote/autonomous control wasn't nearly as established as it is nowadays, different time and acceptance of risks, etc. But 30 odd years later those things have changed and they are/were looking at crew on EM-1 !

What speaks for NASA is that they were asked by the current administration to look into crew on EM-1. NASA did so and (fortunately) concluded that crew on EM-1 was technically possible but not a good idea when viewed from schedule-, financial- and safety repercussions.

NASA never, by themselves, considered putting crew on EM-1. They had learned the lesson from STS-1.
« Last Edit: 01/24/2018 11:20 AM by woods170 »

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #173 on: 01/24/2018 01:23 PM »
As for credibility being shot, the same applies companies that do static fires with a spacecraft attached.

No, that is progress. Doing something new based on prior positive experience and risk analysis. When there is a failure, analyze it, learn from it, re-do risk analysis, take corrective action, continue with an improved design. Far different from putting people on the first flight of a brand new craft.

No, that is not progress, it was the same type of hubris as NASA

Offline abaddon

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #174 on: 01/24/2018 02:59 PM »
I gave up on NASA risk analysis when they made the tortured claim that Ares I would be safer than an EELV.
I'm not sure it's fair to compare NASA under Mike Griffin with the NASA of today.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #175 on: 01/24/2018 04:11 PM »
Cancelled is not the same as never existed. BUT how is it relevant? (rhetorical question, don't answer) ... Please, let's not let this turn into a general NASA bashing thread. Thank you.
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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #176 on: 01/24/2018 05:08 PM »
It is a common practice  to go near a fueled rocket.  See Ice teams, red teams, closeout crew, etc.   

It WAS common practice to go near a fueled Shuttle stack. That does not make it great idea.

Does ULA allow ground crew near a fueled Atlas or Delta?

Yes, every launch vehicle contractor has a crew that is set up to go near a fueled launch vehicle for troubleshooting.  It is not a rare event.

How would SpaceX do that once they start LOX load? At that point they only have a few minutes to launch before the warming prop could cause issues. Not enough time to troubleshoot or fix much of anything before they have to scrub the launch and detank anyway.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #177 on: 01/24/2018 05:46 PM »
What speaks for NASA is that they were asked by the current administration to look into crew on EM-1. NASA did so and (fortunately) concluded that crew on EM-1 was technically possible but not a good idea when viewed from schedule-, financial- and safety repercussions.

NASA never, by themselves, considered putting crew on EM-1. They had learned the lesson from STS-1.

Quote from: nasaspaceflight.com
NASA will not put a crew on EM-1, cites cost – not safety – as main reason

Quote from: Lightfoot
At the end of the day, we found it technically feasible to fly crew on EM-1, as long as we had a commitment of additional resources and schedule

Quote from: NASA Office of the administrator
Based on this study, NASA concluded crew could have flown on Exploration Mission-1 (EM-1), provided timely and sufficient funding, with an increased risk acceptance and moving the launch schedule to most likely early 2020.

While it is good that NASA would not have done this study without external prompting, this is not NASA learning their lesson. Safety is a technical criteria, so saying "technically feasible" means that the safety risks are acceptable, STS-1's lesson was that the risks are not acceptable without a strong reason that crew is required.

Point is analysis based LOC estimates are not as good as flight history, so demonstration requirements applied to CC are good, but should also be applied to all NASA programs. There is nothing magical about NASA that makes their analysis more accurate.

Orbital rocketry is not spacecraft design, these are completely different things.
Anything with rockets is rocketry.  Orbital doesn't mean anything different, same principles apply across the spectrum of missions.
Jim, What are you saying here? NASA missions are generally science missions requiring returning high quality data and operating over a long period of time. These challenges are not related to the challenges of building a rocket that can reliably put them in space to begin with. Rocketry is not involved with most NASA missions, even RCS thrusters aren't necessarily required. Even if you insist on counting RCS thrusters/delta-V engines as rocketry, it is still completely different technology than what is used in orbital class rockets.
« Last Edit: 01/24/2018 05:59 PM by meberbs »

Offline SWGlassPit

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #178 on: 01/24/2018 08:31 PM »
While it is good that NASA would not have done this study without external prompting, this is not NASA learning their lesson. Safety is a technical criteria, so saying "technically feasible" means that the safety risks are acceptable, STS-1's lesson was that the risks are not acceptable without a strong reason that crew is required.

Point is analysis based LOC estimates are not as good as flight history, so demonstration requirements applied to CC are good, but should also be applied to all NASA programs. There is nothing magical about NASA that makes their analysis more accurate.

You really cannot look at that analysis in a vacuum.  You have to consider who directed it and what their motivations are -- i.e., who it's written for.  If the administration comes and says, "what would it take to make this happen?" and you say "it's not safe," you didn't answer their question, and you would quickly find yourself without a job.  You have to answer the question asked.  In this case, they pointed out that making it safe would cost too much.

There are only two reasons governments don't do something: money and politics.  You have to frame the base answer of "it's not safe" in terms of those two, which is what the study did.

Offline kalmes

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #179 on: 01/24/2018 11:20 PM »
I gave up on NASA risk analysis when they made the tortured claim that Ares I would be safer than an EELV.
I'm not sure it's fair to compare NASA under Mike Griffin with the NASA of today.

That's a good point, and the political pressure at the time is very different than today.

Still, I don't like the attitude that safety can simply be bought with enough paperwork. Analysis is certainly essential, but eventually you run into "unknown-unknowns" with novel systems, and it's hard to get to very high levels of reliability without experience with the system. NASA's response was that if they spend enough money, EM-1 will be safe.

There is a lot of heritage in EM-1, and I would ride it given the chance  :). But I don't believe the first launch will be as safe as an Atlas or Falcon flight, no matter how much you prepare. Practical experience with systems that are used over and over again is extremely important to reliability, and I don't see NASA's safety culture embracing that fact.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #180 on: 01/25/2018 06:36 AM »
What speaks for NASA is that they were asked by the current administration to look into crew on EM-1. NASA did so and (fortunately) concluded that crew on EM-1 was technically possible but not a good idea when viewed from schedule-, financial- and safety repercussions.

NASA never, by themselves, considered putting crew on EM-1. They had learned the lesson from STS-1.

Quote from: nasaspaceflight.com
NASA will not put a crew on EM-1, cites cost – not safety – as main reason

Quote from: Lightfoot
At the end of the day, we found it technically feasible to fly crew on EM-1, as long as we had a commitment of additional resources and schedule

Quote from: NASA Office of the administrator
Based on this study, NASA concluded crew could have flown on Exploration Mission-1 (EM-1), provided timely and sufficient funding, with an increased risk acceptance and moving the launch schedule to most likely early 2020.

While it is good that NASA would not have done this study without external prompting, this is not NASA learning their lesson. Safety is a technical criteria, so saying "technically feasible" means that the safety risks are acceptable, STS-1's lesson was that the risks are not acceptable without a strong reason that crew is required.

Emphasis mine.

I disagree with your assessment. SLS is a NASA-run vehicle and, as such, safety can be bought by "designing it in". However, NASA didn't originally consider flying crew on EM-1 because of the increased price tag on an already very expensive vehicle, as well as considerations for crew safety and schedule issues.

When asked by the administration to look into flying crew on EM-1 anyway NASA eventually came to the same conclusion. Putting crew on EM-1 will cost extra, comes with increased risk acceptance and adds delay:

http://spacenews.com/nasa-decides-not-to-place-a-crew-on-first-slsorion-mission/

Quote from: Jeff Foust
“But when Robert (Lightfoot) and I (Bill Gerstenmaier) look at this overall, it does add some more risk to us, because it’s the first crew on the vehicle,” he said. The work to add crew to EM-1 would have cost NASA an additional $600–900 million, and delay the launch likely to the first or second quarter of 2020.

“The culmination of changes in all three of those areas (Risk, Cost, Delay) said that overall, probably the best plan we have is actually the plan we’re on right now,” Gerstenmaier said. “When we looked at the overall integrated activity, even though it was feasible, it just didn’t seem warranted in this environment.”

This clearly shows that safety in fact very much was a factor in deciding NOT to put crew on EM-1. It just wasn't the only factor.

In that respect the headline of Chris G's article is misleading. Cost was not the main reason. It was a combination of three things:
1. Increased risk (related to the safety of the crew flying on a brand new rocket and brand new spacecraft)
2. Additional cost (related to modifying the vehicle and Orion to carry crew)
3. Additional delay (related to the time needed to execute the modifications)
« Last Edit: 01/25/2018 06:38 AM by woods170 »

Online meberbs

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #181 on: 01/25/2018 04:13 PM »
...

While it is good that NASA would not have done this study without external prompting, this is not NASA learning their lesson. Safety is a technical criteria, so saying "technically feasible" means that the safety risks are acceptable, STS-1's lesson was that the risks are not acceptable without a strong reason that crew is required.

Emphasis mine.

I disagree with your assessment. SLS is a NASA-run vehicle and, as such, safety can be bought by "designing it in". However, NASA didn't originally consider flying crew on EM-1 because of the increased price tag on an already very expensive vehicle, as well as considerations for crew safety and schedule issues.
No, you cannot buy safety by just "designing it in." That would fall into the category of "engineering hubris" and it can quite literally get people killed.

This is really where the on topic part of this conversation ends, since this thread is about commercial crew, so the fact that actual unmanned test flight(s) are fundamental to crew safety is relevant. Your misinterpretations and misrepresentations of NASA's decision and their stated reasons for it are not relevant, but for completeness I have addressed them below.

As you said, cost and schedule were driving reasons for the decision, but it is obvious that safety was not. They said the safety risk was acceptable. Doing the right thing for the wrong reasons is not exactly a good thing, just better than both the reasons and the thing being wrong.

...
This clearly shows that safety in fact very much was a factor in deciding NOT to put crew on EM-1. It just wasn't the only factor.
I don't know what you are looking at, because I have no idea how you would draw that conclusion. They admit that the risk is worse, but if you look at the quote I provided which is earlier in that article, it is quite clear that they did not consider that a problem. Also, I think you are making the assumption that risk and safety mean the same thing. They don't, there is a such thing as cost risks and schedule risks for example. Even assuming they were using this interchangeably with crew safety (which may be the case), it is clear that this was not the reason for the decision.

In that respect the headline of Chris G's article is misleading. Cost was not the main reason. It was a combination of three things:
1. Increased risk (related to the safety of the crew flying on a brand new rocket and brand new spacecraft)
2. Additional cost (related to modifying the vehicle and Orion to carry crew)
3. Additional delay (related to the time needed to execute the modifications)
Nope. This is one of the only news sites that doesn't lie with their headlines. While the delay had some influence in the decision, cost was the biggest driver, and the risk was determined to be completely acceptable and therefore a non-factor.
« Last Edit: 01/25/2018 05:07 PM by meberbs »

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #182 on: 01/25/2018 06:23 PM »
...
While it is good that NASA would not have done this study without external prompting, this is not NASA learning their lesson. Safety is a technical criteria, so saying "technically feasible" means that the safety risks are acceptable, STS-1's lesson was that the risks are not acceptable without a strong reason that crew is required.

Emphasis mine.

I disagree with your assessment. SLS is a NASA-run vehicle and, as such, safety can be bought by "designing it in". However, NASA didn't originally consider flying crew on EM-1 because of the increased price tag on an already very expensive vehicle, as well as considerations for crew safety and schedule issues.
No, you cannot buy safety by just "designing it in." That would fall into the category of "engineering hubris" and it can quite literally get people killed.
And yet "designing in" safety is exactly what NASA is doing with SLS and Orion. "Designing safety in" not just refers to the design of the vehicles but also to the procedures used by NASA to reduce risk and increase safety. Such as being in full control of the design and execution of that design. Or requiring one or more demonstration missions before putting crew on a vehicle.

Is that "engineering hubris"? Maybe. But crew safety was designed into SLS/Orion by stipulating that no crew will fly on the first mission. That was (and still is) the original plan, and it is a direct result of the lessen learned from STS-1.


This is really where the on topic part of this conversation ends, since this thread is about commercial crew, so the fact that actual unmanned test flight(s) are fundamental to crew safety is relevant. Your misinterpretations and misrepresentations of NASA's decision and their stated reasons for it are not relevant, but for completeness I have addressed them below.
They are only misinterpretations and misrepresentations in your eye. And I will explain why below.


As you said, cost and schedule were driving reasons for the decision, but it is obvious that safety was not. They said the safety risk was acceptable. Doing the right thing for the wrong reasons is not exactly a good thing, just better than both the reasons and the thing being wrong.

...
This clearly shows that safety in fact very much was a factor in deciding NOT to put crew on EM-1. It just wasn't the only factor.
I don't know what you are looking at, because I have no idea how you would draw that conclusion. They admit that the risk is worse, but if you look at the quote I provided which is earlier in that article, it is quite clear that they did not consider that a problem. Also, I think you are making the assumption that risk and safety mean the same thing. They don't, there is a such thing as cost risks and schedule risks for example. Even assuming they were using this interchangeably with crew safety (which may be the case), it is clear that this was not the reason for the decision.
You did a wonderful job of completely MISinterpreting my post.
My original point was that there were three factors involved in the outcome of the "crew on EM-1"-study. Bill Gerstenmaier mentioned all three during the media teleconference on May 12, 2017. The three factors are:
1. Increased risk. And knowing Bill Gerstenmaier he means Crew Risk (aka: it is less safe to launch a crew on an unproven rocket). He is not referring to schedule risk or financial risk because he refers to those seperately.
2. Additional cost
3. Delay to 2020 (or beyond).

Bill then continues to make clear that the culmination of those three factors led them to stick to the original plan (to not launch crew on EM-1):
Quote from: Bill Gerstenmaier
The culmination of changes in all three of those areas said that overall, probably the best plan we have is actually the plan we’re on right now.
For some inexplicable reason you don't seem to parsing Bill correctly. "All three", as cited by Bill, includes crew risk (and thus crew safety), cost and delay.
You stating that "safety was not a driving reason" is therefore flat out wrong. As is your entire line-of-reasoning regarding this matter.



In that respect the headline of Chris G's article is misleading. Cost was not the main reason. It was a combination of three things:
1. Increased risk (related to the safety of the crew flying on a brand new rocket and brand new spacecraft)
2. Additional cost (related to modifying the vehicle and Orion to carry crew)
3. Additional delay (related to the time needed to execute the modifications)
Nope. This is one of the only news sites that doesn't lie with their headlines. While the delay had some influence in the decision, cost was the biggest driver, and the risk was determined to be completely acceptable and therefore a non-factor.
You seriously believe that NSF is the only site that doesn't occasionally screw-up its reporting?
Mister, that equals to stating that man is infallible. The reporting done here is just as susceptible to an occassional error as any other good space-reporting website.
Misleading can be done intentional and UNintentional. And I thoroughly believe that Chris G UNintentionally emphasized cost over safety when he drew up his article. But, like you, he managed to incorrectly parse what Bill Gerstenmaier actually stated.

It was the combination of the three factors listed above that led to NASA's decision to stick to the original plan (no crew on EM-1)
Your interpretation that crew safety did not play a role is incorrect. And  IMO the reason for your misinterpretation is this: you assume that ONLY safety can be the leading driver for the study that was performed by NASA.
And that is just flat out wrong. In the bigger scheme of things decisions are always taken based on a number of factors involved. Risk, and its effect on safety, is just one factor. Not THE factor.
But clearly, you fail to understand this.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #183 on: 01/25/2018 07:34 PM »
No, you cannot buy safety by just "designing it in." That would fall into the category of "engineering hubris" and it can quite literally get people killed.
And yet "designing in" safety is exactly what NASA is doing with SLS and Orion. "Designing safety in" not just refers to the design of the vehicles but also to the procedures used by NASA to reduce risk and increase safety. Such as being in full control of the design and execution of that design. Or requiring one or more demonstration missions before putting crew on a vehicle.
Designing it in is obviously part of obtaining a safe vehicle, but requiring proof through test and demonstration, is not "designing it in." It is proving it, and is a separate and obviously necessary step. A step that is skipped by your and NASA's claim that crew could have been safely flown on EM-1. Your attempt at redefining this term is both wrong and in obvious contradiction with how you previously used it.

You previously used it to claim that NASA is special and exempt from reality so they can build a safe vehicle on the first try, despite historical evidence to the contrary.

Is that "engineering hubris"? Maybe. But crew safety was designed into SLS/Orion by stipulating that no crew will fly on the first mission. That was (and still is) the original plan, and it is a direct result of the lessen learned from STS-1.
You were defending NASA's claim that they could safely launch astronauts on EM-1. The point you just made is evidence to the contrary. If you are going to change your position to agree with my original point, then please do so explicitly and don't waste time arguing for no reason.

They are only misinterpretations and misrepresentations in your eye. And I will explain why below.
You are obviously trying to retroactively change what you said without admitting to it. It is already clear by this point in your post.


You did a wonderful job of completely MISinterpreting my post.
My original point was that there were three factors involved in the outcome of the "crew on EM-1"-study. Bill Gerstenmaier mentioned all three during the media teleconference on May 12, 2017. The three factors are:
1. Increased risk. And knowing Bill Gerstenmaier he means Crew Risk (aka: it is less safe to launch a crew on an unproven rocket). He is not referring to schedule risk or financial risk because he refers to those seperately.
2. Additional cost
3. Delay to 2020 (or beyond).
Yes, that is what you said before, and you are still misrepresenting the statement that was made. If you are going to claim I misinterpreted something you said, you would have to point to somewhere I claimed you said something different. As I already said, they admitted to the increased risk, but in the part where they explicitly stated the reasons for the decision, they explicitly stated only cost and schedule stating technical (which would include safety) was acceptable.

Bill then continues to make clear that the culmination of those three factors led them to stick to the original plan (to not launch crew on EM-1):
Quote from: Bill Gerstenmaier
The culmination of changes in all three of those areas said that overall, probably the best plan we have is actually the plan we’re on right now.
For some inexplicable reason you don't seem to parsing Bill correctly. "All three", as cited by Bill, includes crew risk (and thus crew safety), cost and delay.
You stating that "safety was not a driving reason" is therefore flat out wrong. As is your entire line-of-reasoning regarding this matter.
Please stop ignoring the multiple quotes I provided a couple posts back that directly contradict your claims. When you look at them in context it is obvious that cost and schedule alone were claimed to be enough to decide against it, and safety alone would not have been.



Nope. This is one of the only news sites that doesn't lie with their headlines. While the delay had some influence in the decision, cost was the biggest driver, and the risk was determined to be completely acceptable and therefore a non-factor.
You seriously believe that NSF is the only site that doesn't occasionally screw-up its reporting?
Mister, that equals to stating that man is infallible. The reporting done here is just as susceptible to an occassional error as any other good space-reporting website.
That is not what I said at all, I did not say that they never make a mistake, I said that the don't write baseless sensational headlines. They obviously make mistakes, but if that was not an accurate and fair assessment of NASA's statements they would change it when someone pointed it out.

Misleading can be done intentional and UNintentional. And I thoroughly believe that Chris G UNintentionally emphasized cost over safety when he drew up his article. But, like you, he managed to incorrectly parse what Bill Gerstenmaier actually stated.
No, you are the one who misinterpreted it, because you continue to ignore what Lightfoot clearly stated in both his quoted statement and in the official letter from the office of the administrator.

And  IMO the reason for your misinterpretation is this: you assume that ONLY safety can be the leading driver for the study that was performed by NASA.
No, I am not making that assumption. Cost and schedule can obviously be factors, but unless the cost was truly astronomical, it would not outweigh the fact that the risk of putting humans on the first launch of a new vehicle is unacceptable. It is hard to outweigh a factor in a trade study that is simply a non-starter.

The rest of your post is you reepeating yourself, as if repeating false statements will make them true.

Offline happyflower

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #184 on: 01/25/2018 09:02 PM »
So I read the last 4 posts. Phew. TLDR: Safety is either #1 or #2 reason NASA wont fly astronauts on EM-1.

Offline woods170

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #185 on: 01/26/2018 06:01 AM »
<Whole lotta OT disagreement between meberbs and woods170>

Clearly we disagree. But I'm not going to pull this thread any further OT than you and I already did.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #186 on: 01/26/2018 11:46 AM »
<Whole lotta OT disagreement between meberbs and woods170>

Clearly we disagree. But I'm not going to pull this thread any further OT than you and I already did.
There is one on topic point though, and you seem to have argued both sides, so can you clarify this:

Do you agree that unmanned test flight(s) before launching crew is fundamentally necessary for crew safety?

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #187 on: 02/19/2018 01:52 AM »
All "unknowns" can be assigned risk factors and those risks can be mitigated in design. This is a core principal of all engineering not just aerospace.

Would you consider STS to be a good example of how all unknowns can be mitigated using NASA design and processes?

Offline su27k

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #188 on: 02/19/2018 02:09 AM »
One reason SLS is so expensive is because of all of these studies done to quantify the risks and then the steps taken to mitigate them. Groups like SpaceX simply ignore much of this process and weather through the consequences by having a cheap system. That is why Dragon 2 as expensive as everything else SpaceX has developed up to this point combined: all the NASA oversight into safety.

Dragon 2 total development cost is about $2B, just 1/7th of Orion's budget after 2010, so it's clear even with NASA safety oversight SpaceX is still crazy cheap, and safety oversight cannot explain SLS's horrendous cost.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #189 on: 02/19/2018 02:11 AM »
Completely ridiculous.
All "unknowns" can be assigned risk factors and those risks can be mitigated in design. This is a core principal of all engineering not just aerospace.
One reason SLS is so expensive is because of all of these studies done to quantify the risks and then the steps taken to mitigate them. Groups like SpaceX simply ignore much of this process and weather through the consequences by having a cheap system. That is why Dragon 2 as expensive as everything else SpaceX has developed up to this point combined: all the NASA oversight into safety.

How can you assign risk factors to something if it is um....unknown?  That is the whole point of unknown-unknowns.  If you can apply a risk factor....then it is a known, not an unknown!

Offline MaxTeranous

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #190 on: 02/19/2018 09:29 AM »
All "unknowns" can be assigned risk factors and those risks can be mitigated in design. This is a core principal of all engineering not just aerospace.
One reason SLS is so expensive is because of all of these studies done to quantify the risks and then the steps taken to mitigate them. Groups like SpaceX simply ignore much of this process and weather through the consequences by having a cheap system. That is why Dragon 2 as expensive as everything else SpaceX has developed up to this point combined: all the NASA oversight into safety.

No they can't. Engineers are not clairvoyants, they can only do mitigation and design around known physics and concepts and use tools and systems that exist to simulate for identify possible issues. Simulations are not perfect, unknown unknowns exist. They can get close certainly, but there is no such thing as 100% perfect design.

Also most of those risk mitigations just are that - mitigations, not solutions to remove the risk entirely. An LOC of 1/350, 1/1,000 or 1/100,000 doesn't mean that it won't fail the very first time regardless.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #191 on: 02/19/2018 02:27 PM »
I gave up on NASA risk analysis when they made the tortured claim that Ares I would be safer than an EELV.
I'm not sure it's fair to compare NASA under Mike Griffin with the NASA of today.

That's a good point, and the political pressure at the time is very different than today.

Still, I don't like the attitude that safety can simply be bought with enough paperwork. Analysis is certainly essential, but eventually you run into "unknown-unknowns" with novel systems, and it's hard to get to very high levels of reliability without experience with the system. NASA's response was that if they spend enough money, EM-1 will be safe.

There is a lot of heritage in EM-1, and I would ride it given the chance  :). But I don't believe the first launch will be as safe as an Atlas or Falcon flight, no matter how much you prepare. Practical experience with systems that are used over and over again is extremely important to reliability, and I don't see NASA's safety culture embracing that fact.
Completely ridiculous.
All "unknowns" can be assigned risk factors and those risks can be mitigated in design. This is a core principal of all engineering not just aerospace.
One reason SLS is so expensive is because of all of these studies done to quantify the risks and then the steps taken to mitigate them. Groups like SpaceX simply ignore much of this process and weather through the consequences by having a cheap system. That is why Dragon 2 as expensive as everything else SpaceX has developed up to this point combined: all the NASA oversight into safety.

NASA has an institutional habit of rationalizing known risks using bad data and assumptions, and even if they didn't, there is no way to do enough analysis to guarantee the safety of a system. But there is an often-demonstrated way to do enough analysis to never get to an actual flight.

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #192 on: 02/19/2018 05:02 PM »
Reflecting further on the claim that rigorous process can remove all risks...

Clearly rigorous design and test processes such as failure mode effects analysis have value. For a critical products (whether critical due to cost, function, or risk to human life), it would be incredibly negligent to shortcut these. In many cases, it is literally criminally negligent when an engineer fails to perform this type of analysis. Presumably SpaceX has quite rigorous process, failure analysis, code and hardware reviews, tests, etc. ... completely apart from anything NASA forces them to do. I can't imagine this not being the case.

So let's shift the discussion to a cost/benefit analysis. *How much* analysis/test/FMEA/process is "best" for rocket development? Rockets are expensive, prone to blow up, carry expensive equipment, and sometimes carry humans. So a lot more of these offsetting processes are needed versus a less critical product.

But any type of test and analysis has a point of diminishing returns. At some point, you've probably found all the problems you are going to find using those methods. But in a complex system, problems are still lurking -- due to things you don't know or incorrect assumptions, problems *will* be missed. No matter how much time & money you spend, you will not find them.

So again, how much is "just right?" The answer is probably very different for different companies, who have different aims and different stakeholders. SpaceX with a single majority shareholder & CEO has the advantage over any public company or government agency because they don't have to worry about skittish stakeholders. SpaceX has freedom of movement, freedom to find problems through failure, that others do not have. And that's a freedom Elon understands to his maximum benefit.

His fail-early fail-often mindset is not just "Silicon Valley" -- it's the massive wave of Software Engineering generally over the last decade. In my discipline, the industry has learned since the 80's at a super rapid pace across thousands of large engineering enterprises creating massively complex software tools... that engineers make mistakes! Lots of them! Even world-class software engineers make a mistake every 100 lines of code. Great process can find a lot of them, but certainly not all. We need the filter of really good test and analysis regimes to clear out the first several rounds of failures... but then we need to test the thing constantly in use, in real world environments, to shake out the remaining issues.

In my view SpaceX is doing it well. As demonstrated with a successful first FH launch campaign, they clearly did a ton of analysis and iterative testing (having designed their whole hardware architecture to be iteratively testable!). But they aren't paralyzed by trying to achieve the unachievable. They are willing to fail in order to learn faster. With the ability to then analyze returned rockets, which no one else in the market can yet perform, they are then able to make the rocket even more reliable due to reams of real-world data.

Offline Kansan52

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #193 on: 02/19/2018 05:30 PM »
... With the ability to then analyze returned rockets, which no one else in the market can yet perform, they are then able to make the rocket even more reliable due to reams of real-world data.

Would you accept an edit to 'unique data' instead of 'reams of ... data'? Everyone has lots of telemetry data. The data gained from analysis of a landed first stage may not deviate much (or any) from the telemetry data. But it is certainly unique.

Online scdavis

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Re: ASAP still has concerns over Commercial Crew LOC risks
« Reply #194 on: 02/19/2018 05:36 PM »
... With the ability to then analyze returned rockets, which no one else in the market can yet perform, they are then able to make the rocket even more reliable due to reams of real-world data.

Would you accept an edit to 'unique data' instead of 'reams of ... data'? Everyone has lots of telemetry data. The data gained from analysis of a landed first stage may not deviate much (or any) from the telemetry data. But it is certainly unique.

I agree that "unique" is the differentiating point -- and a huge advantage. Everyone can run their rocket engines on a test stand. Only SpaceX can recover a booster and look for weak points, cracks, weld issues, fatigue, etc. in the entire booster after experiencing launch acceleration and max Q loads.

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