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SpaceshipTwo crashes shortly after Mojave test flight

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Re: SpaceshipTwo crashes shortly after Mojave test flight

#261

Post by pwnna »

zepolud wrote: post #31

Test pilots? In the 21st century? I find it absolutely reckless and inexcusable to require live humans riding on a prototype rocket when you have all the processing power needed to automate/remote manage the vehicle literally in your pocket. EDIT: To those downvoting, you should really check that all current spaceplanes have the capability to fly and land autonomously--Boeing X-37, Dream Chaser, even Buran was fully…

The following is purely personal opinion. Feel free to disprove me.

I think at the moment, and into the foreseeable future, a human at the pilot seat for an experimental craft, where all sorts of unexpected scenarios could pop up, would be much better suited than an automated "test" pilot, given that sometimes you don't even necessarily have the correct parameters of your plane/rocket to program a successful autopilot.

Keep in mind that people at Virgin Galactic will have finite resources. Even if you can automate something that can access very unexpected situations and make a correct decision on what to do, the cost of doing that vs a test pilot is going to be much higher.

As far as I'm aware, aircraft autopilot systems do not perform well when unexpected mechanical failures occur and usually defer to humans by sounding alarms and such.

As for rockets, especially test ones, usually the automated system that makes a call when mechanical failures occur involves self destruct to prevent collateral damages.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#262

Post by Steko »

marze wrote: post #243
termain wrote: post #215

Earlier quoted context omitted.

Aviation Week reported it back in May. So, yes. I'll keep an eye out for the accident report. http://m.aviationweek.com/space/new-fuel-boost-spaceshiptwo

Well you could be right, but it is very hard to imagine that being true since the plastic hybrid has only been tested once on the ground. Doing a flight test so soon would be totally insane. In any case, the disaster was undoubtably a result of inadequate ground testing. Problems like these are almost always the result of management pushing things faster than the engineering progress warrants.

Virgin has to get Brandon to space this year or their funding is subject to considerable clawback.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#263

Post by Steko »

marze wrote: post #243
termain wrote: post #215

Earlier quoted context omitted.

Aviation Week reported it back in May. So, yes. I'll keep an eye out for the accident report. http://m.aviationweek.com/space/new-fuel-boost-spaceshiptwo

Well you could be right, but it is very hard to imagine that being true since the plastic hybrid has only been tested once on the ground. Doing a flight test so soon would be totally insane. In any case, the disaster was undoubtably a result of inadequate ground testing. Problems like these are almost always the result of management pushing things faster than the engineering progress warrants.

Virgin has to get Brandon to space this year or their funding is subject to considerable clawback.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#264

Post by vacri »

marze wrote: post #246
DanBC wrote: post #76

Earlier quoted context omitted.

> Apollo program, which was well managed and had no in-flight failures that resulted in loss of life The flaws in Apollo One were so severe the three crew died on the launchpad. Describing that tragedy as "no in-flight deaths" is accurate but misses some important information. http://en.wikipedia.org/wiki/Apollo_1

True. But it is almost pointless to compare these two programs since Apollo was so much more complex. To put it in perspective, Apollo flew on a rocket with five engines producing 1,500,000 lbf thrust each, on the first stage alone. By contrast, the Virgin motor produces 60,000 lbf thrust for 70 seconds. The Apollo program had a safety culture configured so that if anyone identified a safety issue, they became respon…

Speaking of perspective, the Apollo was fully-backed by the government of the most powerful economy in the world at the time - 4% of the federal budget was directed towards it, with 34,000 NASA employees and 375,000 third-party employees, with a cost of ~$140B of today's dollars. How the hell is a private company supposed to compete? Not even Apple's famed $100B in cash could pay that bill.

http://en.wikipedia.org/wiki/Budget_of_NASA#Cost_of_Apollo_p...

Edit: It's also worth noting that the same entity that ran the Apollo missions currently has no way of putting people into space, and the last system they had also looked like a plane... and had problems with exploding and killing people.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#265

Post by InclinedPlane »

HarryHirsch wrote: post #192
krisoft wrote: post #33

Earlier quoted context omitted.

All of those you said are very true. It's also worth mentioning that that very 'safe' engine has already killed three people, and injured three others during a cold-flow test. Very tragic. see for details: http://www.knightsarrow.com/rockets/scaled-composites-accide... or the "Test program accident" at the wiki: http://en.wikipedia.org/wiki/RocketMotorTwo

How do you even manage to kill not one but three people with shrapnel during a pressure test? Proper safety procedure demands that anything potentially shrapnel-producing is contained within an enclosure and that engineers are outside the area while testing takes place. The whole incident indicates a lax safety culture.

Precisely. An absence of proper safety procedures is how.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#266

Post by sitkack »

neurotech1 wrote: post #241
robryk wrote: post #221

Earlier quoted context omitted.

According to wikipedia, it was STS-3 that had (autoopilot-induced) oscillations during landing. The description on Wikipedia seems to imply that they were expected (the autopilot was being tested) and that the dangerous condition was due to the autopilot being left partially engaged after the test.

Correct. There was also an pitch stabilization system that malfunctioned due to the misconfigured (partially engaged) autopilot. Point remains that the pilots flying skills in the cockpit saved the orbiter.

And in this case the craft killed the pilot. Shouldn't we be designing pilotless craft?

Re: SpaceshipTwo crashes shortly after Mojave test flight

#267

Post by aptwebapps »

marze wrote: post #246
DanBC wrote: post #76

Earlier quoted context omitted.

> Apollo program, which was well managed and had no in-flight failures that resulted in loss of life The flaws in Apollo One were so severe the three crew died on the launchpad. Describing that tragedy as "no in-flight deaths" is accurate but misses some important information. http://en.wikipedia.org/wiki/Apollo_1

True. But it is almost pointless to compare these two programs since Apollo was so much more complex. To put it in perspective, Apollo flew on a rocket with five engines producing 1,500,000 lbf thrust each, on the first stage alone. By contrast, the Virgin motor produces 60,000 lbf thrust for 70 seconds. The Apollo program had a safety culture configured so that if anyone identified a safety issue, they became respon…

"True. But it is almost pointless to compare these two programs since Apollo was so much more complex."

That's funny, because you were the one who compared them first.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#269

Post by ghostunit »

seanflyon wrote: post #233
ghostunit wrote: post #202

Earlier quoted context omitted.

I find this dogma of "Eventually we will conquer space and make it accessible to all mankind" dangerous in the extreme to the actual, all-too-present predicaments we have here on real Earth such as climate change, environment devastation, fossil fuels/minerals/water depletion and the accelerating destruction of the web of life that makes possible your even being able to breathe. You are all prey to the "religion of p…

> basic hard laws such as the speed of light, the laws of thermodynamics, etc. say NO This is not true. For travel within the solar system the speed of light is no more than a nuisance delaying communication. The laws of thermodynamics don't stop space travel. No one is saying "we always find a way" to do the impossible. We are saying "we always find a way" to do that thing that we already know how to do and have dem…

a) Travel within the solar system? where do you want to go live, Mercury, Venus? Mars is almost as worthless too, its gravity is 1/3 Earth's. Can't live there for long.

b) We just need to make it cheaper? how, exactly, are you going to get up there except by burning obscene quantities of solid (fossil) fuel, as we do now?

That's where the thermodynamics things comes in play: you have to pay the energy cost, there's no elegant "oh, we're just going to fold space" or some such bs. And fossil fuels are finite by definition, need I remind you.

It's not "we just need to make it cheaper". It's coming up with new breakthroughs in physics that no one can assure even exist.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#270

Post by marze »

vacri wrote: post #264
marze wrote: post #246

Earlier quoted context omitted.

True. But it is almost pointless to compare these two programs since Apollo was so much more complex. To put it in perspective, Apollo flew on a rocket with five engines producing 1,500,000 lbf thrust each, on the first stage alone. By contrast, the Virgin motor produces 60,000 lbf thrust for 70 seconds. The Apollo program had a safety culture configured so that if anyone identified a safety issue, they became respon…

Speaking of perspective, the Apollo was fully-backed by the government of the most powerful economy in the world at the time - 4% of the federal budget was directed towards it, with 34,000 NASA employees and 375,000 third-party employees, with a cost of ~$140B of today's dollars. How the hell is a private company supposed to compete? Not even Apple's famed $100B in cash could pay that bill. http://en.wikipedia.org/wi…

Another difference, the Apollo astronauts carried slide rules to do calculations during the mission.
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