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#400
by
erioladastra
on 31 Jul, 2018 17:03
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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.
Actually here VR is pretty useless. Flight simulators are very effective in terms of realism, handling, vehicle response... but in either case you are greatly limited by models (and it take a great deal of effort developing the software, developing the models, VERIFYING and VALIDATING the software and models...).
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#401
by
ChrisGebhardt
on 31 Jul, 2018 19:34
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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.
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.
Exactly. ASAP is not here to divulge proprietary company information (which Merlin 1D details would certainly be considered by SpaceX). They exist to make sure NASA and the CCP - in this case - are acutely aware of issues and doing all they can with the providers to correct issues. The simple fact that these meetings are public is also a large element of transparency and information sharing (as there's nothing in law that mandates these overview meetings be public).
And I would argue the ASAP did reveal new information on the Boeing failure. Boeing's public statement (July 20/21) said they were confident they were moving forward on corrective action. But ASAP noted meetings after that company statement and then clearly stated that Boeing had requested more time to go understand what happened and what design changes might be needed. That's a strikingly different statement from the one Boeing gave and does provide better insight into where Boeing might actually be.
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#402
by
TripleSeven
on 31 Jul, 2018 19:47
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its "possible" to happen, its very unlikely. very very unlikely.
its just test pilots playing. we do that
Actually, 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 trivial
I 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.
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#403
by
TripleSeven
on 31 Jul, 2018 19:58
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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.
Sigh. 20 plus years ago we took the first triple from Seattle to Denver (the old Stapelton airport...) for UAL show and tell (we had to put plywood under the trucks to keep them from sinking into the asphalt. I gave a tour of the plane to some retired UAL pilots, a couple of which had flown the B247...we got them into the simulator and without an exception they all did just fine.
anyway one of them ask me "are you having any trouble with pilots accepting the FBW" and my answer was of course.. He laughed, and told me that on the 247, which had one of the first auto pilots a lot of the pilots that they no longer "had control"
there is no reason in this day and age to 1) have any "non" fly by wire" capability in a modern airplane or spacecraft or ship and soon cars...and 2) if morale is a problem, there are always other people to do the job and 3) anyone who doesnt think that they have full control with FBW, just doesnt understand it
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#404
by
whitelancer64
on 01 Aug, 2018 02:51
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I ran across an interesting tweet!
It says 5-6 months for the first demo flight.
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#405
by
ChrisGebhardt
on 01 Aug, 2018 05:05
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I ran across an interesting tweet!
It says 5-6 months for the first demo flight.
I think Irene means Pad Abort test, not launch abort test.
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#406
by
Steven Pietrobon
on 01 Aug, 2018 05:50
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#407
by
woods170
on 01 Aug, 2018 16:22
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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.
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.
ASAP is not needed to make the facts public. Most, if not all, serious problems make it into the wide open regardless of ASAP.
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#408
by
erioladastra
on 01 Aug, 2018 17:43
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its "possible" to happen, its very unlikely. very very unlikely.
its just test pilots playing. we do that
Actually, 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 trivial
I 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.
Technically ISS doesn't have FBW since no real "fly" controls.
Don't disagree with your other comments (though technical the first issue I referred to was hardware mainly, not software).
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#409
by
gongora
on 01 Aug, 2018 21:33
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Tweets from Eric Berger: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/'19
Pad abort test Spring 2019
Crewed flight test mid-2019
Tweet from Emre Kelly: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.
Tweet from Irene Klotz: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
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#410
by
gongora
on 01 Aug, 2018 23:11
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Tweet from Irene Klotz: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
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#411
by
yg1968
on 02 Aug, 2018 18:30
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#412
by
catdlr
on 07 Aug, 2018 20:42
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Building the Future of Space with Boeing's Starliner
Boeing
Published on Aug 7, 2018
Boeing's CST-100 Starliner is go for launch, ready to take America back to space. The Starliner is a brand new, commercially developed spacecraft, that will usher in a new era of human space exploration. It joins a long line of spacecraft that Boeing or Boeing's heritage companies have developed in collaboration with NASA, including Mercury, Gemini, Apollo and the space shuttle.
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#413
by
catdlr
on 07 Aug, 2018 20:43
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Boeing's Chris Ferguson Going Back to Space
Boeing
Published on Aug 7, 2018
As Boeing's first astronaut test pilot, Chris Ferguson will return to space on board the company's CST-100 Starliner. Ferguson is a retired U.S. Navy captain who piloted STS-115, and commanded STS-126 and STS-135. The Philly native retired from NASA in 2011, and has been an integral part of Boeing's Starliner program.
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#414
by
clongton
on 08 Aug, 2018 15:58
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Regardless of who flies first, the important thing to remember here is that there are 2 extraordinary companies doing extraordinary things to return American astronauts to space, flying in an American spacecraft and launched by an American rocket from American soil. The Atlas-V, while using Russian engines, is nonetheless and American rocket and will be replaced by the Vulcan, an all-American launch vehicle when it comes online. Starliner CST-100, from all we've been able to see and learn, will be a massive step forward in Spacecraft design in terms of safety, efficiency and comfort for the crew. We are all looking forward to her first crewed flight, whenever that may be. Godspeed Chris Ferguson and crew.
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#415
by
Eric Hedman
on 12 Aug, 2018 05:24
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#416
by
Chris Bergin
on 20 Aug, 2018 18:47
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#417
by
jbenton
on 22 Aug, 2018 19:29
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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?
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#418
by
whitelancer64
on 22 Aug, 2018 20:08
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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?
They push the aerodynamic shockwave away from the rocket.
*edit*
Snipped out pictures, and to add:
Earliest mention of it I can find is from April 2015.
https://forum.nasaspaceflight.com/index.php?topic=32438.msg1359475#msg1359475
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#419
by
Lars-J
on 22 Aug, 2018 20:18
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I thought it was more related to aerodynamic stability during an abort, but I could certainly be very wrong.