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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 th
by JanSolo 12y ago
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 two. No turbopumps or gimbals or much mechanical stuff to go wrong. It only goes suborbital, so it does not need a heatshield because there's no re-entry. The landing system uses wings & wheels similar to any commercial jet. This stuff is mature and tested.
In fact, the only novel thing about SS2 is it's wing-feathering system. It's lets the craft to descend vertically still under the pilots control. I wonder if (and this is complete speculation) there was a problem restoring the wings to their 'atmospheric' flight position which prevented them from landing normally.
The consequences for commercial manned spaceflight will be quite severe, I think. I imagine that many Virgin Galactic customers will cancel their pre-orders. The flight test program is dead in it's tracks at this point; even those who don't cancel will be unlikely to fly for many more years while investigations and improvements are concluded.
Other manned providers such as SpaceX and XCor will likely be extra cautious before allowing people to fly in their vehicles.
The image of manned commercial spaceflight will take a hit. If the 'Safest' of the commercial vehicles can crash before it even enters service, I worry that many potential customers will be put off. It never hurts to remember that Spaceflight is a dangerous business.
It's a sad day to top off a bad week in spaceflight. :(
- nawitus 12y agoIt's been reported that it "exploded in mid-air", and two parachutes were deployed, so the cause probably was not the wing-feathering system.
- deleted 12y ago[deleted]
- JanSolo 12y agoYes, looking at the twitter feed, multiple sources state that it blew up. This means that either the tank (which takes up the whole rear half of the vehicle) failed catastrophically (unlikely; CF-wrapped tanks tend to develop hairline cracks which slowly leak out) OR the engine exploded. What's interesting is that the SS2 engine fuel was swapped out very recently for a new thermoplastic polyamide solid fuel for better performace. Maybe this new fuel was not tested as well as it should have been?
- thisGuysAccount 12y agostatic wick failure, minor fuel leak, big bang. That said, I really have no clue about how these things work. That's just one scenario I could see leading to a midair explosion.
- Dylan16807 12y agoAn oxidizer leak isn't going to explode. (And it's pretty hard for a leak of anything to explode much when there's nowhere for it to build up. Limited internal space, wind rushing by...)
- TrevorJ 12y agoMy bet is a hard start.
- cfreeman 12y agoThey 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.
- Fuzzwah 12y agoI hadn't heard about that, thanks for the info. I dug up this article: http://www.parabolicarc.com/2014/10/08/work-continues-hybrid-rubber-engine-spaceshiptwo/ http://www.parabolicarc.com/2014/10/08/work-continues-hybrid...
- cfreeman 12y agoInteresting. I might actually be wrong about the details then. Maybe the new engines they were using is actually a new type of hybrid (nylon)? I know for a fact that they are working on their own liquid engine, but perhaps it wasn't involved in this crash.
- ggreer 12y agoThe 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.
- JanSolo 12y agoAgreed. Don't forget that this is not the first fatality associated with this engine. In 2007, 3 people were killed in an explosion during a static test at Mohave Air & Space port.
- drzaiusapelord 12y agoSo they traded sometimes dangerous moving parts that could lead to a mission fail to a rarely dangerous pressurized vessel that would lead to casualties? Is this a case of not seeing safety's big picture? Cutting accidents in half (or by whatever) is great, but not if that means the remaining accidents are fatal. A more frequent controlled failure is a much better scenario, but I imagine hurts the bottom line too much. I'm wary that for-profit companies aren't going to invest enough in private manned spaceflight's safety when there's a profit incentive at work dictating otherwise. At least without a fair bit of regulation.
- JanSolo 12y agoI think it's very hard to make that determination. In spaceflight, all accidents are likely to be fatal. Also, I have no problem with a profit-motive; killing your passengers is very bad for business.
- damon_c 12y agoYes in this market, the invisible hand will tend to ensure the success of companies that don't blow up their passengers.
- 12y ago
- krisoft 12y agoAll 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-accident/ http://www.knightsarrow.com/rockets/scaled-composites-accide... or the "Test program accident" at the wiki: http://en.wikipedia.org/wiki/RocketMotorTwo http://en.wikipedia.org/wiki/RocketMotorTwo
- smackfu 12y agoYeah, "rocket" + "safe enough to carry tourists regularly" just seems like a difficult combination.
- untog 12y agoMany years ago, trying to combine "flying in the air" with "safe enough to carry tourists regularly" would be seen in a similar light.
- Animats 12y agoIt took 54 years to go from the Wright Brothers first flight to the Boeing 707. It took 53 years to go from Yuri Gagarin's first flight (one orbit) to this suborbital flight test.
- DanBC 12y agoIt only took 8 / 9 years between Gagarin's flight and landing men on the Moon. That's remarkable. It's depressing to think how much closer we'd be to humans on Mars if we had focussed all the Afghan and Iraq war money on space research.
- jacquesm 12y agoOr simply to reduce the national debt.
- 12y ago
- notastartup 12y agosad. also manned flight to mars to colonize it like Musk says seems impossible for at least a couple decades.
- javert 12y agoThe accidents this week seem to have no bearing on that. It may or may not be true, but it's the same thing it was last week.
- avmich 12y ago> SpaceshipTwo is considered the 'simplest' and 'safest' of all the upcoming manned commercial vehicle. XCOR's culture of safety is pretty good, though it's the school of thought quite close to Virgin Galactic . At least rocket engines in XCOR are designed with the highest standards of safety.
- rdtsc 12y agoWell 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 shortage and the future is bright and exciting.
- riffraff 12y agoAFAIR there is an order of magnitude of two between the prospected prices of virgin galactic and a soyuz trip.
- throwaway234 12y agoA ride on Virgin Galactic is $250,000 a ride to the ISS on a soyuz is $70,000,000.
- jcreedon 12y agoThere is also at least an order of magnitude between their maximum altitudes.
- wolf550e 12y agoThe altitude is not important. https://what-if.xkcd.com/58/ https://what-if.xkcd.com/58/ SpaceShipTwo is meant to get to zero velocity at ~105km up. Soyuz gets to 17,450 mph at 200km up (and then catches up to the station at 400km up). Only the speed sideways is important, and there is more than one order of magnitude difference.