SpaceshipTwo crashes shortly after Mojave test flight • Hacker News Board

Re: SpaceshipTwo crashes shortly after Mojave test flight

#41

Post by robertfw » Fri, Oct 31, 2014, 7:24 PM UTC

atlantic wrote: post #30

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…

> This is commendable, and is what drives the human race forward. Without these fearless men we wouldn't have gone to the moon. We wouldn't have explored the depths of the ocean. We wouldn't have flown the skies. That's one way of looking at the matter. Another is that without this untrammelled technological evolution (I hesitate to use the word "progress") we wouldn't be living through the greatest mass extinction e…

I think you'll find that it hard to argue that the efforts of exploration are linked to our industrial pillage of the planet.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#42

Post by mikeash » Fri, Oct 31, 2014, 7:24 PM UTC

atlantic wrote: post #30

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…

> This is commendable, and is what drives the human race forward. Without these fearless men we wouldn't have gone to the moon. We wouldn't have explored the depths of the ocean. We wouldn't have flown the skies. That's one way of looking at the matter. Another is that without this untrammelled technological evolution (I hesitate to use the word "progress") we wouldn't be living through the greatest mass extinction e…

Instead of living through the greatest mass extinction event in the last few million years, we'd be living in harmony with nature, dying of now-curable injuries, starving to death when times are lean, seeing our mothers and wives and daughters die in childbirth, and living in profound ignorance of the nature of the universe.

At least with the mass extinction there are prospects for fixing the problem.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#43

Post by nether » Fri, Oct 31, 2014, 7:25 PM UTC

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…

> cryogenic liquids at -300 degrees celsius

Absolute zero is -273 °C.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#44

Post by sejje » Fri, Oct 31, 2014, 7:26 PM UTC

sp332 wrote: post #15

arjn wrote: post #10

Its very sad but inevitable. At this cutting edge of technology and human endeavour, accidents are bound to happen.

It's not inevitable, as evidenced by all the other accidents that have been... evited. You just don't hear about those. (Yes, evited is a word, it's just weird.)

Maybe it's inevitable in the sense that all the accidents can't be evited.

Eventually you'll have one.

( Chrome doesn't think evited is a word. )

Re: SpaceshipTwo crashes shortly after Mojave test flight

#45

Post by untog » Fri, Oct 31, 2014, 7:26 PM UTC

smackfu wrote: post #36

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

Yeah, "rocket" + "safe enough to carry tourists regularly" just seems like a difficult combination.

Many years ago, trying to combine "flying in the air" with "safe enough to carry tourists regularly" would be seen in a similar light.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#46

Post by Fuzzwah » Fri, Oct 31, 2014, 7:27 PM UTC

cfreeman wrote: post #24

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…

They just switched to a new liquid powered engine because their hybrid engine was not powerful enough. This was the first powered test flight with their new engine, and given the information so far it sounds like it exploded in-flight. Very, very, tragic. edit: I'm wrong. They simply switched to a new type of fuel for their hybrid engine.

I hadn't heard about that, thanks for the info.

I dug up this article:

http://www.parabolicarc.com/2014/10/08/work-continues-hybrid...

Re: SpaceshipTwo crashes shortly after Mojave test flight

#47

Post by [deleted] » Fri, Oct 31, 2014, 7:27 PM UTC

tomrod wrote: post #35

atlantic wrote: post #30

Earlier quoted context omitted.

> This is commendable, and is what drives the human race forward. Without these fearless men we wouldn't have gone to the moon. We wouldn't have explored the depths of the ocean. We wouldn't have flown the skies. That's one way of looking at the matter. Another is that without this untrammelled technological evolution (I hesitate to use the word "progress") we wouldn't be living through the greatest mass extinction e…

Until when? The next large asteroid? The next close-by gamma burst? The sun goes nova? Let's go see the universe, and take life along with us.

[deleted]

Re: SpaceshipTwo crashes shortly after Mojave test flight

#48

Post by JanSolo » Fri, Oct 31, 2014, 7:27 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

You are right. Hybrid engines are not looking like the safe & reliable middle-ground between solid & liquid engines that they were made out to be.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#49

Post by nether » Fri, Oct 31, 2014, 7:28 PM UTC

atlantic wrote: post #30

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…

> This is commendable, and is what drives the human race forward. Without these fearless men we wouldn't have gone to the moon. We wouldn't have explored the depths of the ocean. We wouldn't have flown the skies. That's one way of looking at the matter. Another is that without this untrammelled technological evolution (I hesitate to use the word "progress") we wouldn't be living through the greatest mass extinction e…

Kaczynski was right.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#50

Post by jcrites » Fri, Oct 31, 2014, 7:28 PM UTC

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…

> Most systems operate in extreme conditions, sometimes bordering on the improbable.

Indeed. Your statement reminds me of an insightful engineering article, "How Complex Systems Fail": http://www.ctlab.org/documents/How%20Complex%20Systems%20Fai... . A few relevant observations from the article that resonate with me:

> 1) Complex systems are intrinsically hazardous systems.

> 4) Complex systems contain changing mixtures of failures latent within them.

> 5) Complex systems run in degraded mode.

> A corollary to the preceding point is that complex systems run as broken systems. The system continues to function because it contains so many redundancies and because people can make it function, despite the presence of many flaws. After accident reviews nearly always note that the system has a history of prior ‘proto-accidents’ that nearly generated catastrophe.

> 17) People continuously create safety.

> Failure free operations are the result of activities of people who work to keep the system within the boundaries of tolerable performance. These activities are, for the most part, part of normal operations and superficially straightforward. But because system operations are never trouble free, human practitioner adaptations to changing conditions actually create safety from moment to moment.