Quote from: woods170 on 01/24/2018 11:18 amWhat 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.comNASA will not put a crew on EM-1, cites cost – not safety – as main reasonQuote from: LightfootAt 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 scheduleQuote from: NASA Office of the administratorBased 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.
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.
NASA will not put a crew on EM-1, cites cost – not safety – as main reason
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
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.
“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.”
Quote from: meberbs on 01/24/2018 05:46 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.
...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.
...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)
Quote from: woods170 on 01/25/2018 06:36 amQuote from: meberbs on 01/24/2018 05:46 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.Quote from: woods170 on 01/25/2018 06:36 am...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.
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.
Quote from: woods170 on 01/25/2018 06:36 amIn 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.
Quote from: meberbs on 01/25/2018 04:13 pmNo, 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.
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.
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.
They are only misinterpretations and misrepresentations in your eye. And I will explain why below.
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 cost3. 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 GerstenmaierThe 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.
Quote from: meberbs on 01/25/2018 04:13 pmNope. 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.
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.
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.
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.
<Whole lotta OT disagreement between meberbs and woods170>
Quote from: meberbs on 01/25/2018 07:34 pm<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.
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.
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.
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.
Quote from: kalmes on 01/24/2018 11:20 pmQuote from: abaddon on 01/24/2018 02:59 pmQuote from: kalmes on 01/24/2018 03:11 amI 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.
Quote from: abaddon on 01/24/2018 02:59 pmQuote from: kalmes on 01/24/2018 03:11 amI 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.
Quote from: kalmes on 01/24/2018 03:11 amI 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.
I gave up on NASA risk analysis when they made the tortured claim that Ares I would be safer than an EELV.
... 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.
Quote from: scdavis on 02/19/2018 05:02 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.