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.
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?
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...
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.
Quote from: woods170 on 01/19/2018 09:30 amThat 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.
Quote from: Steven Pietrobon on 01/18/2018 05:17 amThat'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.
That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.
Quote from: Ugger55 on 01/19/2018 01:17 pmWith 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.
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).
Quote from: Space Ghost 1962 on 01/19/2018 08:48 pmAssuming 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.
Quote from: Steven Pietrobon on 01/20/2018 04:45 amQuote from: Ugger55 on 01/19/2018 01:17 pmWith 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,
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.
Quote from: rockets4life97 on 01/19/2018 01:25 pmSeems 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.
Quote from: Jim on 01/21/2018 05:23 pmQuote from: rockets4life97 on 01/19/2018 01:25 pmSeems 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!
Quote from: deruch on 01/20/2018 06:10 amQuote from: woods170 on 01/19/2018 09:30 amThat 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.
Quote from: jak Kennedy on 01/19/2018 03:28 pmQuote from: Jim on 01/19/2018 02:31 pmQuote from: Ugger55 on 01/19/2018 01:51 pmTo 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.
Quote from: Jim on 01/19/2018 02:31 pmQuote from: Ugger55 on 01/19/2018 01:51 pmTo 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'.
Quote from: Ugger55 on 01/19/2018 01:51 pmTo 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.
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,
Quote from: woods170 on 01/22/2018 09:59 amI'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?
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.
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.