Starliner faced “catastrophic” failure before software bug found(arstechnica.com) |
Starliner faced “catastrophic” failure before software bug found(arstechnica.com) |
I guess some things just never get old, citing from https://en.wikipedia.org/wiki/Soyuz_5 :
"The flight was also memorable for its dramatic re-entry. The craft's service module did not separate, so it entered the atmosphere nose-first, leaving cosmonaut Boris Volynov hanging by his restraining straps. As the craft aerobraked, the atmosphere burned through the module. But the craft righted itself before the escape hatch was burned through."
This actually happened three times so far with the Soyuz (in all cases without the loss of crew):
"An incomplete separation between the Service and Reentry Modules led to emergency situations during Soyuz 5, Soyuz TMA-10 and Soyuz TMA-11, which led to an incorrect reentry orientation (crew ingress hatch first)."
(from https://en.wikipedia.org/wiki/Soyuz_(spacecraft)#Service_mod...)
One would kinda expect that past crewed vehicle emergencies would be studied in detail when designing a new one & that the developers would make extra sure they can't reasonably happen with their design.
Basically, all space capsules have their of gravity placed in such a way that they will automatically orient themselves heat shield forward once they encounter the atmosphere. So once the service module is gone, it should flip into the correct orientation just by physics alone.
(BTW, this is the same reason why the Crew Dragon spacecraft keeps it's aft section "ring" attached during a launch escape, where it's super draco thrusters drag it to a safe distance from a failing launcher.
The aft ring prevents the capsule from trying to flip over during the abort. Then once in safe distance from the vapor & debris cloud that used to be the launcher, the aft section is jettisoned and the capsule again automatically re-orients itself heat shield forward.)
Uh, that's extremely concerning for a CREWED capsule.
(Where's Margaret Hamilton when you need here?
too late. Boeing is already deep in Agile, a methodology which promises that a child can be delivered by the way of 9 incremental monthly deliveries.
https://www.infosysconsultinginsights.com/2019/06/12/the-ris...
"Boeing was an early Agile adopter in 2008 surpassing its rival, Airbus, in 2012 by deploying a newly renovated 737 Max 8 faster to market.
[...]
The 2008 article Boeing Frontiers- Goin’ Agile by Doug Cantwell from Boeing describes how Boeing, in partnership with Lockheed Martin, created an Agile lab to move changes to the aircraft to market it faster, cutting down flight test times from months to days. "
You don’t do your software development in increments smaller than a month? What does that mean, you spend two months just writing specs?
I am always skeptical of any argument that is unfamiliar, but more and more it does appear that NASA has lost its way. The shuttle was an obvious mistake in retrospect; there may even be some credibility to the obscure theory that NASA only did it to further separate themselves from DoD. I think NASA has become a political creature that is less concerned with science and more concerned with SCIENCE™. If this is the case, they will fight tooth and nail against any expansion of manned space exploration (because it will be both private and military in nature), the will fight against innovation that doesn't spring from their own workshop(s), and they will use Cape Canaveral (and their heritage facilities/infrastructure) as a way to bully "adversaries" into submission.
I hope this isn't the case, and if it is, I hope they can reverse whatever practices and policies that have led us to where we are. As it stands though, it appears NASA is more like OSHA then it is like its historical instance.
There are uncrewed test flights for a reason. You can't always simulate every possible failure mode. Things fail on the ground that wouldn't be possible during normal operation and vice versa.
Also, the crew would first have to know something wrong is going on either based on activity happening that was not planned previously or unexpected data on flight instruments. But guess what is driving those instruments in a modern crewed space vehicle - also computers and software. That software might be faulty as well or even displaying the same wrong data the automated control software is acting upon.
In such a case the crew might not even notice something is wrong until the craft is on a wrong and potentially even unrecoverable trajectory once ground radar notices something is wrong.
As for the crew taking over thtuster control during a reentry - sorry, if you space capsule is trying to kill you that hard, something is wrong.
At that point in time, the capsule is hurtling through the atmosphere protected only by its from ablative shield. The thrusters are used to shift the center of gravity a bit, to give the capsule some lift, offsetting some of the g forces due to the rapid deceleration. This is called "lifting reentry".
This all needs to be very very precise & based on up to date sensor data, as the whole capsule is not covered by the heat shield and if you change the center of gravity too much, you might expose unprotected parts of it to the hot plasma.
This is not really a good environment for a crew member to take over - not only are you under couple g's of deceleration but any mistake will kill you all. But hey, no pressure!
BTW, the Soyuz capsule has a backup mode available in case it's reentry control thrusters fail, where the capsule just follows an unguided ballistic reentry. This is much harder on the crew (due to no lift compensating for some of the deceleration), but survivable & has been used a couple times during various emergencies.
This should be concerning, then:
https://spaceflightnow.com/2019/11/04/boeing-starliner-pad-a...
> “Boeing is not going to do an in-flight abort test,” said Jon Cowart, deputy manager of the mission management office for NASA’s commercial crew program, before the pad abort test. “They’re just going to do the ground one. They think that they can get enough data and then extrapolate that out, with good analytical techniques that we’ve endorsed. They will go and do it in that particular way, versus SpaceX, which is going to do both.
If the schedule called for simulations to be run in parallel with the live test, then it's an expected outcome. It should be _expected_ that every test will find a problem. Since this was uncrewed, there was no risk (other than to the uncompleted tests possibly requiring a second flight) to running them in parallel and porting across fixes for any problems that were found.
It was a schedule compression attempt with a cost of second test flight risk if it failed.
In theory Boeing ran all their simulations over the past couple years, and this flight should have just been a formality. As it turns out, Boeing is running into a lot of issues when they actually test their hardware.
This is editorializing but it looks like Boeing didn't uncover very complicated interactions - they failed at a more basic level of competency - timer synchronization for the launch issue and then a major software bug for an important orbital maneuver. Those sorts of issues really should be sorted out on the ground using hardware simulators. Furthermore, the timer synchronization failure prevented testing of the docking hardware, further delaying the overall program.
For a human rated vehicle, personally I think you should have at least one full-up, fully nominal test before you send anyone along for the ride.
But more importantly - where is the fun in that?
Would you want to board that capsule yourself, otherwise?
> Why not focus on remotely controlled or AI autonomous vehicles instead?
Buzzwords doesn't make something more reliable/less error prone. You really think that by throwing in something like AI, which can fail in unexpected ways, be a good idea?
NASA has always been a political creature, but its mission has changed over the years. Its original mission was to beat the USSR into space. Its new mission is to funnel money to key congressional districts. But it has always been political. Science was always a facade.
Source: I worked for NASA for 15 years (1988-2000, 2001-2004).
What does this statement really add besides political signaling?
Can you provide a link about that? I'm aware about SpaceX-NASA cooperation in debugging SpaceX disasters and also financial assistance from NASA on various stages of SpaceX evolution, but would like to learn about substantial involvement of NASA into important technical design and development processes in SpaceX.
What's the point of delivering this type of software piecemeal? A new airliner takes 10 years or so to produce. There's no value in shipping half an airplane.
Having one that has sophisticated automation which you need to constantly monitor in case it tries to kill you due to a simple programming error is not really comparable I'm afraid.
This is a welcome development.
That sort of thing is rarely organized. So we test it instead.
At the core of the issue though, the process that SpaceX pitched to NASA (and NASA approved) involved quite a bit of actual hardware testing. Boeing's plan (also approved by NASA) relied much more heavily on simulation, modelling, and other sorts of process validation. For instance, Boeing did not perform an in-flight abort.
"In a salient departure from traditional engine design, NASA and its business partners have adapted commercial, off-the-shelf technologies and common manufacturing methods to develop the Fastrac engine. Significant involvement by small business has aided in broadening the competition and producing lower cost hardware.
For example, Barber-Nichols, Inc. of Arvada, Colo., worked alongside Marshall engineers to design and manufacture the turbopump. The Colorado-based company is experienced in building turbomachinery for the automotive industry and chemical plants, and not traditionally associated with the aerospace industry. The company helped design a turbopump for the Fastrac engine that can be built easily using commercial manufacturing techniques."
Sounds like NASA itself took help from the industry then.
https://en.wikipedia.org/wiki/Merlin_(rocket_engine_family)
"The SpaceX turbopump was an entirely new, clean sheet design contracted to Barber-Nichols, Inc. in 2002 who performed all design, engineering analysis, and construction; the company had previously worked on turbopumps for the RS-88 (Bantam) and NASA Fastrac engine programs."
Turbopump is often the most complex part of the engine; doing it from scratch raises doubts how much the engine was derived.
I don't think NASA helped to SpaceX that much before Falcon-1 reached the orbit.