Virgin Galactic spaceship crashes
 

Very sad. I feel for those who lost their lives in this. I'm certain the program will recover but it will likely be set back many years...

The notion that a government-run is somehow better or safer is sheer idiocy and has no basis in fact. Government experimentation and development in aerospace has a mighty high body count and some spectacular failures too. Ever hear of Apollo 1? How about the Challenger disaster? Columbia? How many rockets blew up on takeoff in the early 1960s? Answer: "a lot". How many test pilots have been killed in the development of aircraft? Again, "a lot".

The point is that when anyone - government or private - plays around in the realm of aerospace it is inherently dangerous and there are going to be failures and people are going to die. It's the nature of human beings doing anything involving technology to survive in a realm where we're not naturally adapted to exist in. The same thing happens in extreme climates (mountaineering, sea exploration, etc.)

All of the technologies we enjoy and take for granted today are built on the backs of risks taken by others in the past. Many of those who pioneered those technologies died in their development too. Part of the price of human progress. Obviously we try to minimize risk and anticipate problems as technologies are developed but it does happen sometimes. We are hardly infallible.

I had not seen the 71,000 feet.

Their airfame design concept has been proven with SpaceShipOne reaching space, so it's a matter of scale (not intending to make a pun about Scaled Composites). Not an insurmountable challenge but not as simple as it sounds I am sure.

Yeah, scaling up, and you have to scale up the scale up. (not linear)

My cursory take: They are hitting 71kft without payload. They have ways to go, and the fact that they were experimenting with a different rocket fuel is not a good sign.

How much heavier is SS2 than SS1?

I don't know.

looking up...

Loaded weight: 7,920 lb (3,600 kg)

SS2
Loaded weight: 9,740 kg (21,428 lb)

per Wikipedia

so ~3x

considering that they are going from one pilot (SS1) to two + 6 passengers.. that's light.

also note that the A-12 (SR71) had a service ceiling of 95,000 ft. (Absolute ceiling I would expect to be a good deal higher)
...they were punching around at Mach 3.5, and at that altitude, in the 60's - the 60's! ... and doing that speed/alt w/o rocket propulsion. -- I would rather have a ride in one of those old-school Ti air-breather jets than in these CF "space" ships. --ymmv

Some pretty harsh comments. They were [I]testing[I] this ship, and from what I know that is a graduated program, they don't take it to max altitude the first few rounds especially when testing new fuels. And testing new fuels is hardly a bad sign considering the success of the first fuel used, obviously they are anticipating increased performance to a degree that warrants the change. These guys are flying to space remember, not even remotely a safe endeavor on the best days. In the developmental stages set backs are inevitable and are experienced in every program of this type. Modern jet fighter aircraft manufacturers suffer hull losses in most every testing program of new platforms many with fatalities. The gulfstream 650 is a clean sheet design private aircraft, just a business jet, and test pilots were killed during the development.
Rattan and virgin have a laudable safety record and very thorough practices, they are hardly amateurs and I think probably know what they are doing at this point.

2007 - 3 died when testing nitrous flow. -- SpaceShipTwo - Wikipedia, the free encyclopedia

my take:

http://forums.pelicanparts.com/uploa...1414868442.jpg

http://forums.pelicanparts.com/uploa...1414868378.jpg

I also have to say that I'm not so sure about reports of the engine (and new fuel) causing the problem.


This photo is why.


http://forums.pelicanparts.com/uploa...1414868800.jpg

Appears that the rocket-plane is lost (tumbling) while the engine is intact.

Sorry pal but you cost too much.

The original heroic men.

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I don't understand that interest to get up to 70,000 feet for 5 minutes at the price of $200,000! It's not like going into orbit. Big deal! I once took a Concorde flight from New York to London at 56,000 feet with Mach 2 and 1 price of $1,200.-. They even served a great 1st class meal to boot!

Please review the facts:

http://www.virgingalactic.com/space-vehicle-facts.pdf



+1

How quickly we forget a little over 100 years ago when guys were testing flight with fabric and wood... not much of a "smoking hole" left after those crashes but a lot of people still died so we could have commercial flight today...

Yep. The American attention span, aided by an often hysterical news media, is about 90 seconds at best.

Because for some people $200k is like $20 to you or me. It's no big thing.

If you have it, why not?

Why do people keep comparing today's ego-driven race to the mesosphere to the national effort for technological superiority of half a century ago? North American X-15 - Wikipedia, the free encyclopedia (it still hold the rocket-plane altitude record, btw)

That is, what these guys are doing now pales in comparison to what was done some 50 years ago. And yet people keep making claims about the need to perform highly volatile experiments. This is 2014, where massive computational power is at the disposal of any of these guys. And, rocket science has been well formed, well proven, by generations past; who got there, btw, with slide-rules and massive testing.

PS. I expect that Boeing will have a reliable hypersonic mesosphere-riding transport before these guys. (If they don't already)

Yeah, it is likely a bad sign.

What it says to me (pure speculation) is that they quickly found that they don't have enough energy for that craft (SS2) to make spec. ...or over-heats, or costs too much, or...

Or maybe, you think they are simply looking for a greener refinement? ...save the planet and all that rot that guys like Branson are for :rolleyes: Because, space(ish) joy-rides for Billionaires ...

meh, I really haven't been following this much. The tech simply doesn't much impress me. seems gimmicky.

Rocket engine is a solid particle fuel with an external oxidizer. It allows a solid booster to be stopped and restarted. They are much less volatile than liquid fuels. And while they changed the fuel recently, the engine design was such that either fuel particles could be used.

Catastrophic engine failure is much less likely with SRBs. And if had been like the Antares failure, the whole craft would have been destroyed. I'm guessing it was a structural issue.

Yeah, the hybrid solid rocket engine was the most intriguing thing about SpaceShipOne.

Have you heard any insider analysis of the failure? Seems unusually quiet on that front.

In the meantime... Looking at the engines... compared to the X15

1943 began the development of the first rocket motor of the X15 -they used 2 of these reaction motors for one X-15. Reaction Motors XLR11 - Wikipedia, the free encyclopedia

Replaced in 1960 with one XLR99

This 1960 engine, it appears, puts out 95% thrust of SS2 engine, but can sustain burn time of 150 seconds, vs the needed 60 seconds burn of the SS2 engine.

Looking at those rough thrust numbers and the relative sizes of the SS2 vs the X-15 (like a shuttle-cock vs a dart), and seeing the altitude records of the X-15... I dunno... maybe that SS2 is a lot slippery (at Mach >1) than it appears.

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I will say I do like composites, a lot, but ... maybe not the best idea here.