Pardon me if this has already been discussed. However, I would be interested to know how Soyuz scores based on the same criteria.
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/
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) metricsB. DoD’s Search and Rescue posture and capabilityC. the possibility of aborts taking place in sea states that would be unsafe for rescue.”
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.”
As for the sea state concern during ascent, how much more difficult would this be than having theneed to a trans-atlantic abort site during the shuttle era?
Rephrasing the point, how much would beprobability of meeting launch commit criteria be lowered if the sea state was added to the ratherlarge list of constraints that already exists.
Quote from: duh on 08/23/2017 08:11 pmAs for the sea state concern during ascent, how much more difficult would this be than having theneed 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 moreQuote from: duh on 08/23/2017 08:11 pm Rephrasing the point, how much would beprobability of meeting launch commit criteria be lowered if the sea state was added to the ratherlarge list of constraints that already exists.It already is for the barge and it was also for other manned capsule missions.
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.
Quote from: ElGuapoGuano1 on 08/23/2017 04:26 pmPardon 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 ESAShttps://www.nasa.gov/pdf/140639main_ESAS_08.pdfWhich 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.
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.
No idea: But STS had 1 in 50, so 2%. Seems NASA wS OK with that.
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.
All this had wringing would magically go away if Orion/SLS was the only US system of choice available to fly to ISS...
...it was all kinda arbitrary to begin with in my opinion.
*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*
Quote from: Rocket Science on 08/24/2017 12:33 pmAll 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?
Quote from: woods170 on 08/24/2017 06:04 am*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.
Quote from: whitelancer64 on 08/24/2017 02:22 pmQuote from: woods170 on 08/24/2017 06:04 am*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.
From the article, and just so we more directly discuss/debate the issues:QuoteThe 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) metricsB. DoD’s Search and Rescue posture and capabilityC. 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.
>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.
Quote from: docmordrid on 08/25/2017 08:46 amIMO, 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.
Quote from: woods170 on 08/24/2017 05:18 pmQuote from: whitelancer64 on 08/24/2017 02:22 pmQuote from: woods170 on 08/24/2017 06:04 am*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."
Quote from: SWGlassPit on 09/01/2017 06:26 pmwoods170 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..
Quote from: RonM on 09/04/2017 03:48 pmThat 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 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.
I think both the Star liner and Dragon beat Soyuz by having less separation events and three parachutes.
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.
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.
Quote from: Patchouli on 09/05/2017 01:33 amI 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.
NASA might be able to do a "block buy" and get perhaps 20-30 CRS/CC flights for every big capsule flight.
Quote from: Space Ghost 1962 on 11/12/2017 05:40 pmNASA 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.
Quote from: rayleighscatter on 11/12/2017 08:14 pmQuote from: Space Ghost 1962 on 11/12/2017 05:40 pmNASA 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?
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.
Quote from: Space Ghost 1962 on 11/12/2017 08:56 pmQuote from: rayleighscatter on 11/12/2017 08:14 pmQuote from: Space Ghost 1962 on 11/12/2017 05:40 pmNASA 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.
Quote from: rayleighscatter on 11/12/2017 08:14 pmQuote from: Space Ghost 1962 on 11/12/2017 05:40 pmNASA 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.
Quote from: Space Ghost 1962 on 11/12/2017 05:40 pmNASA 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?
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.
Quote from: woods170 on 11/13/2017 07:13 amQuote from: Space Ghost 1962 on 11/12/2017 08:56 pmQuote from: rayleighscatter on 11/12/2017 08:14 pmQuote from: Space Ghost 1962 on 11/12/2017 05:40 pmNASA 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.QuoteRight 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.
Quote from: woods170 on 11/13/2017 07:13 am...QuoteRight 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....
...QuoteRight 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....
Quote from: rayleighscatter on 11/25/2017 01:56 pmSo 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.QuoteBecause 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!
The point is that actual, repeated flight data of vehicle gives you bounds/reasons/means for safety improvement.
Ok, to dumb it down then:Quote from: Space Ghost 1962 on 11/12/2017 08:56 pmThe 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.
At SpaceX, every design and operation decision is driven by safety and reliability. SpaceX recognizes thatsome proposed operating procedures for the crew transportation system differ from those on the SpaceShuttle Program. SpaceX has elected to adopt certain approaches, including propellant loading afterastronauts 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, afterastronauts 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 ensuresthat astronauts have escape capability during any time propellant is on the launch vehicle, and it does notexpose ground crew to unnecessary risk. Notably, the Space Shuttle continued loading liquid hydrogen forthree hours (“Space Shuttle Replenish” procedure) after astronauts were aboard; propellant loading onFalcon 9 consumes approximately 30 minutes, reducing the time astronauts are exposed to loadingoperations.We have also worked closely with NASA to further enhance the robustness of our composite overwrappedpressure vessels (COPVs) and to ensure NASA is comfortable with their performance in a variety of flightenvironments. We are confident that this process is safe, and we are working closely with NASA tocomplete the ongoing, rigorous analysis necessary to achieve certification.
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.
Quote from: punder on 01/17/2018 05:01 pmThe 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.
Wow this thread is like Deja vu all over again from AMOS-6...
Quote from: Rocket Science on 01/17/2018 07:26 pmWow this thread is like Deja vu all over again from AMOS-6... 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.
Quote from: punder on 01/17/2018 08:09 pmQuote from: Rocket Science on 01/17/2018 07:26 pmWow this thread is like Deja vu all over again from AMOS-6... 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.
Quote from: punder on 01/17/2018 08:09 pmQuote from: Rocket Science on 01/17/2018 07:26 pmWow this thread is like Deja vu all over again from AMOS-6... 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.
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.
So are the Dragon and the Starliner more dangerous for the astronauts to fly in then the Soyuz?
Quote from: Negan on 01/17/2018 09:24 pmSad 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 = 4Number 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 = 0.016Expected loss SpaceX procedure = n*q*2*p = 0.008What 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.
Expected loss standard procedure = 2*n*2*q*p = 4*n*p = 0.016Expected loss SpaceX procedure = n*q*2*p = 0.008What 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.
Quote from: Negan on 01/17/2018 09:24 pmSad 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.
Quote from: Steven Pietrobon on 01/18/2018 05:17 amQuote from: Negan on 01/17/2018 09:24 pmSad 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.
Quote from: Steven Pietrobon on 01/18/2018 05:17 amExpected loss standard procedure = 2*n*2*q*p = 4*n*p = 0.016Expected loss SpaceX procedure = n*q*2*p = 0.008What 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.
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.
Quote from: rockets4life97 on 01/18/2018 07:07 amQuote from: Steven Pietrobon on 01/18/2018 05:17 amQuote from: Negan on 01/17/2018 09:24 pmSad 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.
That's 19 times in a row since the last fuelling explosion on 1 September 2016 with AMOS 6.
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.
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.
Quote from: abaddon on 01/18/2018 03:08 pmAlso 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?
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.
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?
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.
Quote from: kevinof on 01/19/2018 08:40 amSo 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?
What is not common is to be near a rocket while it is in the process of being fueled. See Amos-5.
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.
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
Quote from: Jim on 01/19/2018 12:43 pmApollo 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 possibleCould 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....
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.Quote from: Ugger55 on 01/19/2018 01:17 pmQuote from: Jim on 01/19/2018 12:43 pmApollo 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 possibleCould 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....
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,
But we don't seem to trust that system during fuelling.
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.
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: kevinof on 01/18/2018 02:33 pmNope. 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.
Quote from: RDoc on 01/19/2018 06:14 pmQuote from: kevinof on 01/18/2018 02:33 pmNope. 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.
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'.
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.
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: 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.
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?
Quote from: Jim on 01/19/2018 12:36 pmIt 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?
Quote from: envy887 on 01/22/2018 05:20 pmIt 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.
Quote from: envy887 on 01/22/2018 05:20 pmQuote from: Jim on 01/19/2018 12:36 pmIt 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.
Quote from: Jim on 01/22/2018 07:53 pmQuote from: envy887 on 01/22/2018 05:20 pmQuote from: Jim on 01/19/2018 12:36 pmIt 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?
Quote from: mn on 01/22/2018 12:48 pmQuote 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? 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.
... 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....
Quote from: Johnnyhinbos on 01/22/2018 08:06 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...
Quote from: whatever11235 on 01/22/2018 07:47 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.
{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?
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.
Quote from: A_M_Swallow on 01/23/2018 01:34 amWhen 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.
Quote from: woods170 on 01/23/2018 07:15 amQuote from: A_M_Swallow on 01/23/2018 01:34 amWhen 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.
Either SLS will get cancelled or NASA will get caught.
A difference between the SLS and Orion's LOC to the ISS and CCDev LOC needs explaining and authorising. Possibly by Congress.
Quote from: A_M_Swallow on 01/23/2018 08:57 amEither 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.
Congress is specifying the SLS's high level requirements. It can add LOC and LOM to maximum payload mass.
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.
...Atlas V launched what, 8-10? ...
Quote from: woods170 on 01/23/2018 07:15 amQuote from: A_M_Swallow on 01/23/2018 01:34 amWhen 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?
Quote from: abaddon on 01/23/2018 05:27 pm...Atlas V launched what, 8-10? ...6
Quote from: AncientU on 01/23/2018 01:44 pmThis is based on the premise that NASA knows what it is doing in rocketry... see? And it does. https://www.nasa.gov/missions
This is based on the premise that NASA knows what it is doing in rocketry... see?
Orbital rocketry is not spacecraft design, these are completely different things.
As for credibility being shot, the same applies companies that do static fires with a spacecraft attached.
Quote from: meberbs on 01/24/2018 12:57 amOrbital 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.
Quote from: Jim on 01/24/2018 01:12 amQuote from: meberbs on 01/24/2018 12:57 amOrbital 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 !
Quote from: Jim on 01/24/2018 01:12 amAs 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.
I gave up on NASA risk analysis when they made the tortured claim that Ares I would be safer than an EELV.
Quote from: envy887 on 01/22/2018 05:20 pmQuote from: Jim on 01/19/2018 12:36 pmIt 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.
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.
Quote from: meberbs on 01/24/2018 12:57 amOrbital 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.
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.
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.
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.
“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.
... 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.