Virtual reality has progressed quite a bit, I can't help thinking that simulating mission failures like this will just keep getting easier and maybe even cheaper.
Quote from: woods170 on 07/31/2018 10:31 amWith all due respect Chris but I disagree. The recent ASAP released zero new information about the nature of the Boeing hot-fire issue or the nature of the snag that's hit Merlin 1D qualification. ASAP only reported that there are problems, but not what those problems are.The transparency Chris is alluding to is not the details of the nature of the problems but that there were, in fact, problems. Most company PR departments, left to their own devices, would hide the fact from the public that there were problems because it's not good PR. In this case the ASAP made sure those facts were made public.
With all due respect Chris but I disagree. The recent ASAP released zero new information about the nature of the Boeing hot-fire issue or the nature of the snag that's hit Merlin 1D qualification. ASAP only reported that there are problems, but not what those problems are.
Quote from: TripleSeven on 07/28/2018 07:32 pmits "possible" to happen, its very unlikely. very very unlikely. its just test pilots playing. we do thatActually, there is a small, non-zero chance of the computers failing. In fact, twice in the life of the ISS we have already seen three cases where the triple-redundant command and control computers have failed - one case was d3 different hardware failures ("can't ever happen" they said), one was a software issue and one was an environment issue. In the case of an aircraft you have the luxury of thousands and thousand and thousands of hours testing and flying the software that you won't get with a single spacecraft system. So a chance of a software issue is much higher - even if the hardware has already been shown to be pretty robust. NASA already did a bunch of assessment runs to see how things performed. Some level of manual flying will be developed because psychologically the astronauts will drive it. But as you note, not massively trained because that is a huge expense for minimal benefit.
its "possible" to happen, its very unlikely. very very unlikely. its just test pilots playing. we do that
Virtual reality has progressed quite a bit, I can't help thinking that simulating mission failures like this will just keep getting easier and maybe even cheaper.Also, study after study has found that the best way to improve crew moral is to give them (and especially the pilot and commander) the feeling that they are in control, no matter what.
I ran across an interesting tweet! It says 5-6 months for the first demo flight.
Quote from: erioladastra on 07/30/2018 02:15 pmQuote from: TripleSeven on 07/28/2018 07:32 pmits "possible" to happen, its very unlikely. very very unlikely. its just test pilots playing. we do thatActually, there is a small, non-zero chance of the computers failing. In fact, twice in the life of the ISS we have already seen three cases where the triple-redundant command and control computers have failed - one case was d3 different hardware failures ("can't ever happen" they said), one was a software issue and one was an environment issue. In the case of an aircraft you have the luxury of thousands and thousand and thousands of hours testing and flying the software that you won't get with a single spacecraft system. So a chance of a software issue is much higher - even if the hardware has already been shown to be pretty robust. NASA already did a bunch of assessment runs to see how things performed. Some level of manual flying will be developed because psychologically the astronauts will drive it. But as you note, not massively trained because that is a huge expense for minimal benefit.I did not say there was a "zero chance" of the computers failing...I am saying that at least as commercial and military planes (and now ships and soon cars) operate, the chance is trivialI guess I will hold my opinions of NASA software and hardware on the space station to myself...but this line kind of got me" In the case of an aircraft you have the luxury of thousands and thousand and thousands of hours testing and flying the software that you won't get with a single spacecraft system. "In the old days I "cut my teeth" on the FBW system of the B777..after working on the autoland system (and flight testing it) I got assigned to Triple development...and had a reasonable role in the FBW system including some coding, etc and ground and flight testing of the FBW system...I dont think I agree with you statement. If NASA has troubles with the stations FBW systems...its because they dont do it well..the triple software was more or less "finished" well before the airplane flew. It had been extensively tested on the ground and then in flight simulation. During the 8000 or so test flight hours, there were some changes but they were all quite trivial in terms of certification and operation.and there have been really no significant changes since certification. Now I would assume that some of the changes in the ISS FBW had to happen as the station evolved...but the station now should be a fairly mature (and more or less static) system...so well the run time should be very high. If there are significant issues still happening...thats an engineering and management problem"Some level of manual flying will be developed because psychologically the astronauts will drive it"that should not be tolerated. it was tolerated in the shuttle with the lack of an autoland operational system and it cost a lot of money to continue that.
On call with @BoeingSpace's John Mulholland. He says Starliner on track for late 2018/early 2019 uncrewed flight test. Crew flight test should come mid-2019....More from Mulholland: Looking at other rockets that could launch Starliner, especially Vulcan. Launch tower designed to account for Vulcan's larger size....One effect of the service module hot fire anomaly is that Boeing will now conduct the pad abort test after the first uncrewed test of Starliner. So:Uncrewed flight test end of '18/'19Pad abort test Spring 2019Crewed flight test mid-2019
Boeing update on Starliner anomaly: Happened during simulated low-altitude abort burn. All four engines were nominal until shutdown 1.5 seconds later; several valves failed to close, causing the leak. Boeing's Mulholland confident confident in corrective actions.
seems pretty straightforward change -- also plan to change downstream valve start position to avoid initial surge. Test was designed to check how system worked and apparently a slight tweak or two needed. Boeing clear this wouldn't show up during single-engine test
from interview with Mulholland yesterday, yes design issue affected four of eight identical valves ( four engines --Aerojet-- each with a fuel and an oxidizer valve). Aiming for pad abort April, CTF May. AvWk story should come out of paywall soon
Does anyone know the purpose of those perforated panels on the Starliner's SM?*****The ones that look like the dive flaps on a WWII-era dive bomber:*****What do Starliner's panels do? Do they add stability on launch or something?