SpaceshipTwo crashes shortly after Mojave test flight • Hacker News Board

Re: SpaceshipTwo crashes shortly after Mojave test flight

#161

Post by scott_s » Fri, Oct 31, 2014, 9:12 PM UTC

DanBC wrote: post #76

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…

> 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

Yes, and to bolster your point, they halted the program to re-evaluate safety. I think it's a human fault that we have to learn from our mistakes - unless we make them, people just don't believe the risks are real.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#162

Post by winslow » Fri, Oct 31, 2014, 9:12 PM UTC

zepolud wrote: post #152

apr wrote: post #110

Earlier quoted context omitted.

I think armchair quarterbacking is reckless and inexcusable. These people has been working on airplanes and space crafts for some time now and I would trust their judgment. Especially given that they put their own lives on the line.

"These people" that designed the spaceplane didn't put their lives on the line, they put the lives of the pilots on the line. And I would trust the judgment of the engineers at Boeing, Sierra Nevada, SpaceX, Lockheed-Martin and the entire Soviet space program over theirs.

Really... You are going to trust the entire Soviet space program compared to the engineers behind this project? I really don't think they were being reckless with having pilots. Ultimately, their plan was to take other patrons up to space. You will need personal (experienced space flight attendants) while conducting the flight. This is obviously tragic and my thoughts go out to the families affected. However, when you are trying to do something as complex as space travel and leaving earth you will unfortunately have mishaps and deaths.

Please have a look here - http://en.wikipedia.org/wiki/Soviet_space_program#Incidents....

Re: SpaceshipTwo crashes shortly after Mojave test flight

#163

Post by Metapony » Fri, Oct 31, 2014, 9:13 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…

I'm finding this whole thread interesting, but your comment is the inspirational one I'd hoped to find. Thanks.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#164

Post by brent_noorda » Fri, Oct 31, 2014, 9:14 PM UTC

pessimizer wrote: post #90

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…

You're forgetting how cool it would be for rich people to burn a couple hundred thousand to fly in space for two and a half hours. It's clearly the highest expression of the human spirit, and you're a hopeless hater cynic. I wonder what the carbon footprint of space tourism is, and will be if it becomes cheaper and more popular? I feel guilty flying on a plane.

I worked out some quick math estimating 25,000 gallons just for the fuel for each tourist's 2-hour flight. Space tourism seems like the douchebaggiest idea ever created. I hope the in-flight space cocktails are worth it. http://brent-noorda.blogspot.com/2014/05/richard-branson-elo...

Re: SpaceshipTwo crashes shortly after Mojave test flight

#165

Post by termain » Fri, Oct 31, 2014, 9:14 PM UTC

jobu wrote: post #136

ggreer wrote: post #28

Earlier quoted context omitted.

The engine has been the bane of SS2. The original rubber/N2O design was problematic enough that Virgin switched from rubber to a plastic. Apparently this was the first powered flight to use the new fuel. While the design lacks complicated turbopumps and cryogenic fuels, it does have one drawback: the N2O is contained in a pressure vessel. If that tank is damaged while still full (or close to), bad things can happen.

Looking more into their design turns up all sorts of issues with nitrous oxide as a propellant. It's used all the time in dentist offices, so it's easy to misunderstand as an innocuous gas. At higher pressures and relatively normal temperatures it can go supercritical and become very, very volatile. At that point it's an even better solvent than supercritical CO2, and still a very strong oxidizer: http://www.knightsa…

Well, you want it to be a strong oxidizer, that's its purpose in the rocket.

Strong oxidizers are almost universally hard to handle. About the nicest ones around are Lox, Nox and hydrogen peroxide.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#166

Post by larrydag » Fri, Oct 31, 2014, 9:15 PM UTC

This reminds of studying the Space Shuttle Challenger as part of my Engineering training at school. We studied it as part of an ethics in engineering lesson. The Space Shuttle labels certain components as "Criticality 1". A Criticality 1 component means there is no back up system and failure can lead to catastrophic consequences during Space Shuttle operation, especially at launch. As you may guess the O-rings on the Space Shuttle rocket boosters were graded as Criticality 1. The Space Shuttle had over 700 components graded as Criticality 1.

http://articles.chicagotribune.com/1986-03-18/news/860120045...

Space vehicles and space exploration is a very dangerous and high risk endeavor. This week we are unfortunately reminded of this fact. Thoughts go out to the families of the brave pilots and those with the Virgin Galactic program.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#167

Post by anentropic » Fri, Oct 31, 2014, 9:17 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…

well, I don't think it can have been the rubber because it says in the article:

"During the nine months since the previous rocket-powered test in January, Virgin Galactic switched SpaceShipTwo's fuel mixture from a rubber-based compound to a plastic-based mix"

Re: SpaceshipTwo crashes shortly after Mojave test flight

#168

Post by zepolud » Fri, Oct 31, 2014, 9:22 PM UTC

smackfu wrote: post #137

untog wrote: post #45

Earlier quoted context omitted.

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

Fair point, but the failure modes of flying seem to be more addressable than those of rockets. Like if the airplane engine is essential, add enough that you can tolerate a failure. If control surfaces are essential, add redundant systems. Whereas the failure mode of rockets tends to be exploding, and that's pretty hard to mitigate.

The failure modes of rocket engines could be explosions but nobody says you can't have multiple redundant engines on a single rocket. In fact, in 2012 Falcon 9 demonstrated exactly that: one of their 9 Merlin engines blew up but the rest redistributed the load and the rocket successfully delivered the payload to the ISS[1].

[1] http://blogs.discovermagazine.com/badastronomy/2012/10/08/sp...

Re: SpaceshipTwo crashes shortly after Mojave test flight

#169

Post by gohrt » Fri, Oct 31, 2014, 9:25 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.

Humanity is not going to keep itself together long enough to be threatened by the sun's nova.

Re: SpaceshipTwo crashes shortly after Mojave test flight

#170

Post by gohrt » Fri, Oct 31, 2014, 9:28 PM UTC

winslow wrote: post #162

zepolud wrote: post #152

Earlier quoted context omitted.

"These people" that designed the spaceplane didn't put their lives on the line, they put the lives of the pilots on the line. And I would trust the judgment of the engineers at Boeing, Sierra Nevada, SpaceX, Lockheed-Martin and the entire Soviet space program over theirs.

Really... You are going to trust the entire Soviet space program compared to the engineers behind this project? I really don't think they were being reckless with having pilots. Ultimately, their plan was to take other patrons up to space. You will need personal (experienced space flight attendants) while conducting the flight. This is obviously tragic and my thoughts go out to the families affected. However, when yo…

So the pilot died in order to make Richard Branson's space tourists have a safer and more enjoyable weekend. Cool.