SpaceshipTwo crashes shortly after Mojave test flight • Hacker News Board

Re: SpaceshipTwo crashes shortly after Mojave test flight

#191

Post by neurotech1 » Fri, Oct 31, 2014, 10:13 PM UTC

kashkhan wrote: post #109

marze wrote: post #69

Earlier quoted context omitted.

Some say this is an "inevitable" result of pushing boundaries. No. This is the result of a poorly managed program. What they are doing is much easier than the Apollo program, which was well managed and had no in-flight failures that resulted in loss of life, while accomplishing an infinitely harder task. This is a tragedy, obviously. But the program is about six years behind schedule, been going for 10 years. The mos…

there's no need not in this day and age to have test pilots. If they use computers, they can debug the engine in flight conditions by running maybe ten times as many test flights. Delays of months between flights are dangerous. Until you have a 1000-10,000 flights to build up operational data and envelope, this is a death trap causing unnecessary deaths.

Your forgetting the countless times that a test pilot has saved the aircraft/spacecraft from destruction. If it was unmanned and flown by computer, it would have been a fireball.

At least one shuttle flight would have been lost if the crew didn't fly manually to correct for a malfunction. STS-4 PIO'd on landing and would have crashed if auto-stabilization wasn't overridden by the pilot.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#192

Post by HarryHirsch » Fri, Oct 31, 2014, 10:16 PM UTC

krisoft wrote: post #33

JanSolo wrote: post #18

This is very bad. Not just for the family and friends of the poor guy who died, but for commercial manned spaceflight in general. SpaceshipTwo is considered the 'simplest' and 'safest' of all the upcoming manned commercial vehicle. It has many features that should help keep it reliable. For example, instead of a real liquid rocket engine, it uses a hybrid engine; it has almost no moving parts apart from a valve or tw…

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.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#193

Post by jcreedon » Fri, Oct 31, 2014, 10:21 PM UTC

riffraff wrote: post #138

rdtsc wrote: post #118

Earlier quoted context omitted.

Well Soyuz still flies and has exceptionally low human fatality rates in the last decades. So if safetey realiability is desired it could be just "buy a ride on a Souyz" for now. I think it won't be that dire. People who sign up to fly into space on a new design would probably be aware of the risks involved. Many people still climb Everest, dive into caves, and jump from clifs with wingsuits. I think there won't be a…

AFAIR there is an order of magnitude of two between the prospected prices of virgin galactic and a soyuz trip.

There is also at least an order of magnitude between their maximum altitudes.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#194

Post by atlantic » Fri, Oct 31, 2014, 10:23 PM UTC

JoeAltmaier wrote: post #134

atlantic wrote: post #120

Earlier quoted context omitted.

If we can't even save our own home world, there is every reason to believe that we will do damage elsewhere. That being the case, best to stay home until we grow up a bit.

The rest of our solar system is rocks. Hard to do much damage there. Anything we do has to be for the better (oxygen, water, life).

Are you sure? I get the impression we're not very good at recognizing other life forms, or alternative forms of intelligence.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#195

Post by marze » Fri, Oct 31, 2014, 10:29 PM UTC

termain wrote: post #159

marze wrote: post #69

Earlier quoted context omitted.

Some say this is an "inevitable" result of pushing boundaries. No. This is the result of a poorly managed program. What they are doing is much easier than the Apollo program, which was well managed and had no in-flight failures that resulted in loss of life, while accomplishing an infinitely harder task. This is a tragedy, obviously. But the program is about six years behind schedule, been going for 10 years. The mos…

"The most stupid thing they've done is stay with an experimental rubber/nitrous hybrid engine this whole time, instead of switching to liquid/liquid engine, a well proven technology." 1. They didn't stay with rubber/nitrous. 2. Like the sort used on Antares? "Seeing only the first paragraph, I already know that some rubber in the hybrid engine detached blocking the nozzle and causing the whole engine to explode." But…

"1. They didn't stay with rubber/nitrous."

This you believe so strongly because a news story stated it?

Wait for the accident report. It will say "rubber".

Re: SpaceshipTwo crashes shortly after Mojave test flight

#196

Post by ninjaplease » Fri, Oct 31, 2014, 10:31 PM UTC

venomsnake wrote: post #115

sliverstorm wrote: post #92

Earlier quoted context omitted.

Some say this is an "inevitable" result of pushing boundaries. No. This is the result of a poorly managed program. Some of the boundaries that are being pushed are how much oversight, how meticulous, etc you have to be. In other words, how well you have to manage the program, how tight a ship you keep. Keeping a tight ship raises costs, and isn't the big emphasis of all this privatized space travel on reducing costs?

Costs are fixed. It is up to the culture to choose whether to pay in blood or treasure.

Are you a professional quote maker?

Re: SpaceshipTwo crashes shortly after Mojave test flight

#197

Post by abandonliberty » Fri, Oct 31, 2014, 10:32 PM UTC

marze wrote: post #69

mixmax wrote: post #23

What this weeks events show us is that space travel is hard. Really hard. Most systems operate in extreme conditions, sometimes bordering on the improbable. Thousands, sometimes millions of horsepower in an engine smaller than a car, cryogenic liquids at -200 degrees celsius cooling a nozzle that is 3000 degrees celsius 5 millimeters away, heatshields designed to absorb obscene amounts of heat, the list just goes on…

Some say this is an "inevitable" result of pushing boundaries. No. This is the result of a poorly managed program. What they are doing is much easier than the Apollo program, which was well managed and had no in-flight failures that resulted in loss of life, while accomplishing an infinitely harder task. This is a tragedy, obviously. But the program is about six years behind schedule, been going for 10 years. The mos…

You are certainly very good at finding evidence to validate your prejudice.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#198

Post by marze » Fri, Oct 31, 2014, 10:32 PM UTC

termain wrote: post #159

marze wrote: post #69

Earlier quoted context omitted.

Some say this is an "inevitable" result of pushing boundaries. No. This is the result of a poorly managed program. What they are doing is much easier than the Apollo program, which was well managed and had no in-flight failures that resulted in loss of life, while accomplishing an infinitely harder task. This is a tragedy, obviously. But the program is about six years behind schedule, been going for 10 years. The mos…

"The most stupid thing they've done is stay with an experimental rubber/nitrous hybrid engine this whole time, instead of switching to liquid/liquid engine, a well proven technology." 1. They didn't stay with rubber/nitrous. 2. Like the sort used on Antares? "Seeing only the first paragraph, I already know that some rubber in the hybrid engine detached blocking the nozzle and causing the whole engine to explode." But…

"2. Like the sort used on Antares?"

I think Paul McCartney was about 23 years old when the engines powering that Antares launch vehicle were fabricated in Russia in their race against the Americans to the moon. An antique liquid/liquid vs an inadequately qualified hybrid: no winners.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#199

Post by thelucky41 » Fri, Oct 31, 2014, 10:33 PM UTC

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…

I dream of one day becoming a test pilot. Especially in ships during their developmental stages, unaccounted for situations will come up, and a human capable of assessing and managing these situations are necessary.

For each of the technologies involved with the X-37, et al., that technology required testing with a human-in-the-loop to act as the judge for if the control output made sense. It simply isn't feasible to begin testing your robot pilot without first testing it with a pilot there in the first place.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#200

Post by dennisgorelik » Fri, Oct 31, 2014, 10:34 PM UTC

fidotron wrote: post #186

dennisgorelik wrote: post #145

Earlier quoted context omitted.

Is it cheaper to pay by adding extra complexity into legal contracts, extra labels, and extra training across organization vs just paying up for fixing the consequences of an outlier accident?

The point is beyond an unintuitively small size outliers become practical inevitabilities. This isn't black swan stuff either, but just simple percentages. If you're a small company you generally get to deal with each and every case, and do risk assessment up front on an individual basis. When you're big you're doing enough jobs to standardise those assessments (getting the economies of scale going), processes, and a…

"Inevitable" does not mean "must prevent no matter what cost to prevent is".