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Virgin Galactic Executive Summary of Submission on SpaceShipTwo Accident (parabolicarc.com)
79 points by aerocapture on July 28, 2015 | hide | past | favorite | 37 comments



The full transcripts were posted on the nasa spaceflight forum here: http://forum.nasaspaceflight.com/index.php?topic=35974.440. One user provided the following summary:

> There was corporate conversational knowledge that unlocking the feather system during the transonic region would be catastrophic, but this knowledge wasn't formalized into the pilot handbook or in training. There was formal knowledge that unlocking late would lead to a flight abort, and a recent event had occurred where the unlock was late. Add to this copilot workload increases between flights, the fact that training wasn't done in the suits and equipment worn on the real flight or under the g and vibration loads in the flight, and the result was the copilot unlocked the feather early leading to the loss of the vehicle. As usual, not a single failure, but a chain of smaller failures - lack of formalization of knowledge, lack of training in the operational environment, recent events, pressure to avoid an abort, and you get an overcompensation.


They should just do all this in software. Anything that that's complex and life or death should be autopilot driven.


99 Percent Invisible just had some interesting episodes on automation and autopilot, especially as it relates to air travel:

    http://99percentinvisible.org/episode/children-of-the-magenta-automation-paradox-pt-1/
and self-driving cars:

    http://99percentinvisible.org/episode/johnnycab-automation-paradox-pt-2/


And then you get an autopilot that under abnormal conditions doesn't realize it should deploy the parachute...


Almost everything an autopilot should do should have a button and a switch for humans. The switch prevents the autopilot from doing it, the button makes it happen.

This isn't to disparage autopilots, but to assure control. The human should always be in control of the system, and capable of deciding when things happen.


And in this case, would have pushed the button too early, resulting in the exact same outcome.


No, in this case, by far the most likely outcome is the autopilot would have pushed the button at the right time, creating no need for the copilot to override it.


How do you figure? Pilot thinks "I think it's time to push the button." Autopilot doesn't push button. Pilot says "autopilot is broken. I need to override." Pilot pushes button early.

If the pilot thinks the button needs pushing, they're not going to wait til after the crash to see if the autopilot is working.


What happened here wasn't that the copilot sat there waiting for the intended time to come about and pressed the button exactly at that intended time and just didn't know what the time was supposed to be. What happened was that he was frantically trying to concentrate on a zillion things at once and pressed the button a bit early because he thought otherwise he might end up pressing it too late and he had been warned about the dangers of pressing it too late but not about the dangers of pressing it too early. If there had been an autopilot, most likely the autopilot would have pressed the button at the right time while he was looking at something else.


Lol. Got em


> Anything that that's complex and life or death should be autopilot driven.

What's your stance on autopilot driven cars and trucks?

Arguably, roadway accidents far, far outnumber the number per-capita of space accidents.


> What's your stance on autopilot driven cars and trucks?

The sooner we can switch to them, the better...

> Arguably, roadway accidents far, far outnumber the number per-capita of space accidents.

... for this reason.


> "When accomplished at 1.4 Mach or greater (as required per the SpaceShipTwo checklist procedures and the PF-04 test card) the feather system remained retracted due to a sufficient closing pre-load from the feather actuators and favorable, tail-down aerodynamic loads."

> "On normal rocket-powered flights, checklist procedures called for this step to occur after rocket motor burn out while in space just prior to apogee."

I still haven't seen any information on exactly why this particular flight test card called for actuating the feather mechanism at some time other than apogee. Were they trying to test the flying qualities while feathered at a particular dynamic pressure? It doesn't make any sense for the copilot to move the unlock lever while the aircraft was still accelerating unless the test card called for it. And if it did, then did the engineers and test planners fail to take this possible failure mode into account before the flight?


The feather is always unlocked during ascent, in order to make sure the unlock mechanism works. If the unlock mechanism fails at apogee, the ship will not be able to decelerate appropriately and will overspeed and break up in reentry.



Why are these ships manned?


You're the second guy to say this. Stop and think... Ready for it?

Because it was only months away from carrying tourists. You'll scare the tourists if you're afraid to use a human pilot.


I bet the tourists are pretty scared now.


Only 3% have asked for refunds as of 5th November last year[1]. Could be more now, of course, but demand is still high. They'll sell the returns no matter what.

[1]http://www.theguardian.com/science/2014/nov/05/virgin-galact...


Said tourist checking in. Still keeping my ticket I purchased over 4 years ago. Space is hard and I'll go when they're ready.


Sorry for the irrelevant comment, but I'm so jealous!

I hope you have a great (and safe) ride!


One of the reasons why people can take a cheap flight across continents today is because people risked their lives trying it.

Of course, today there's automation, but it only goes so far

Somebody has to take the first step



A little OT, but the contrast between SpaceX and The Spaceship Company is striking. Elon Musk is pushing for interstellar travel, while Branson is pushing for space tourism. Seems so petty in comparison.


It's all good. They're bringing more money to an industry that can then fund further development. Google, for example, is mostly an ad company. They've taken all that money and built some pretty cool stuff. Among other things, we should get self-driving vehicles and futuristic robots with that money.

So, the 62 mile high space tourist plane will turn into an one orbit trip in a few years. Then to the moon in 25.


Just sort of FYI, in 1969 I was promised a tourist space station I could visit in 25 years by NASA ... (well and their lapdogs the Scholastic Press :-)


Was that the year NASA's budget was almost 4.5% of the federal budget?

http://images.huffingtonpost.com/2012-04-30-Presentation1-th...

The money dried up fast. Now it's up to private enterprise.


Ask your politicians for the lack of funding, then. Those guys are remote controlling robots on the surface of another planet for more than 10 years. They are capable of sending you to a tourist attraction in space with enough funding.


At one point I was lobbying my congressional representative to add a section to the IRS1040 forms that said "2% of your taxes will be allocated to one of the following projects (select one) if you so mark." and then have NASA, Park Service, Pure Science, etc. All things that get short changed. Let the people vote every year on where to send that small pittance.


If Branson is able to make space flight mundane (b/c so many people do it) and/or put "a resort on the moon," I can't see how that wouldn't push things forward.


Maybe space tourism increases public interest in interstellar travel?


Extremely likely due to the overview effect.

https://en.wikipedia.org/wiki/Overview_effect


Your comment reveals stunning ignorance of Burt Rutan's contributions to aerospace.


You're talking about different timescales. Interstellar travel is the long-term goal, but everyone understands it's not going to happen in the next decade. Thus, SpaceX is launching satellites and space station cargoes and The Spaceship Company is debugging a suborbital tourist vehicle, because these are things it is feasible to do right now.


I don't really follow SpaceX to know what Elon Musk is pushing for, but as a practical engineer it seems unlikely that he would be pushing for something that is outside the realm of what physics considers at all possible.


SpaceX has a current mission of reducing launch costs and providing low-cost launch services, with a long term goal of helping humanity settle other planets (mars being the first, perhaps only planet mentioned right now). Interplanetary is well within our realm. Interstellar, not currently.


So then zapt02 misspoke.




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