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-   -   Virgin Galactic SpaceShipTwo Crashed (https://www.cableforum.uk/board/showthread.php?t=33699235)

LSainsbury 31-10-2014 18:52

Virgin Galactic SpaceShipTwo Crashed
 
Reports of Virgin Galactic SpaceShipTwo has crashed...


One parachute in the desert and vehicle crashed...

---------- Post added at 18:39 ---------- Previous post was at 18:38 ----------

Update: Link

---------- Post added at 18:52 ---------- Previous post was at 18:39 ----------

Unconfirmed: One of the pilots dead. :-(

Sirius 31-10-2014 21:22

Re: Virgin Galactic SpaceShipTwo Crashed
 
May the pilot rest in peace.

Sad day for those involved.

http://www.bbc.co.uk/news/world-us-canada-29857182

Quote:

At least one person is dead and another injured after Virgin Galactic's SpaceShipTwo space tourism craft crashed in a California desert, the California Highway Patrol has said.

Hugh 31-10-2014 21:23

Re: Virgin Galactic SpaceShipTwo Crashed
 
What a shame - hope it doesn't delay further flights.

Pierre 31-10-2014 22:33

Re: Virgin Galactic SpaceShipTwo Crashed
 
Quote:

Originally Posted by Hugh (Post 35738405)
What a shame - hope it doesn't delay further flights.

Some hope.

This will severely delay the whole project, might even derail the whole thing.

I don't know many millionaires that would sign up to fly into space on a ship that recently plummeted to the earth.

It will take a lot to bounce back from this.

Chris 03-11-2014 10:41

Re: Virgin Galactic SpaceShipTwo Crashed
 
After a weekend of doomsayers running round the newspapers yelling "I TOLD YOU SO!" and blaming the 'inherently dangerous' rocket engine, it is beginning to look like pilot error may have played a part, and that the engine had nothing to do with it.

http://www.bbc.co.uk/news/world-us-canada-29876154

The feathers which rotate to a 90° angle to the fuselage to slow the vehicle on descent, are held level via two control levers. The first is a lock/unlock safety lever. The second is the rotate control. The unlock lever is not meant to be moved until the rocket engine has cut out and acceleration has ended. Two seconds prior to the accident, the co-pilot released the unlock lever for an unknown reason. After this, the feathers moved by themselves, i.e. the rotate control was not used. VG has not offered an explanation for this however I'd have thought it logical that once the feathers were unlocked, external forces could cause them to move.

Furthermore, all the engine parts and fuel tanks have been recovered, and are intact.

Osem 03-11-2014 10:53

Re: Virgin Galactic SpaceShipTwo Crashed
 
There does seem to be quite a lot of media driven hysteria about this - I've heard several radio debates the premise of which seems to be that Branson's project should be abandoned. Yes it is a tragedy but those calling for the programme to be terminated will happily go about their business in cars, trains, planes etc. without thinking one jot about the countless people who're killed and maimed every year doing exactly the same thing. If we'd followed their dubious logic where would the world be right now?

heero_yuy 03-11-2014 11:27

Re: Virgin Galactic SpaceShipTwo Crashed
 
When your running on the edge of new technology there's always a risk factor: The Apollo program killed three astronaughts on the launch pad (Apollo one fire) yet that went on to put man on the moon.

In the tech race in the fifties test pilots were being killed every week as they pushed the boundaries yet without that effort we wouldn't have the safe air transport that we currently enjoy.

Pierre 03-11-2014 12:24

Re: Virgin Galactic SpaceShipTwo Crashed
 
Quote:

Originally Posted by heero_yuy (Post 35738816)
When your running on the edge of new technology there's always a risk factor: The Apollo program killed three astronaughts on the launch pad (Apollo one fire) yet that went on to put man on the moon.

In the tech race in the fifties test pilots were being killed every week as they pushed the boundaries yet without that effort we wouldn't have the safe air transport that we currently enjoy.

Very true, but they were military people. Professionals involved in a cutting edge project, paid and selected for their experience and skills.

Whereas the Virgin proposition is a leisure experience, taking paying customers on a day trip.

When the dreamliner was thought to have a faulty battery, no planes had crashed, they grounded the whole fleet.

There will be a thorough investigation, as Chris points out it looks like it could be pilot error.

but it will take time and it might jeopordise the project, depends whether the fare paying millionaires are happy that the risk of another crash is low.

Many further test flights will have to be undertaken, incident free, to remove those fears.

Chris 03-11-2014 12:54

Re: Virgin Galactic SpaceShipTwo Crashed
 
I'm going to stick my neck out and suggest that the cockpit instrument and control design is weak. It seems unlikely that the co-pilot would deliberately unlock the feather control at a time when keeping it locked was essential to the craft's safety. Therefore, what action should the co-pilot have been performing at that point, where is the control relevant to that, and how easily confused is that control, with the feather lock lever?

Sparkle 03-11-2014 19:13

Re: Virgin Galactic SpaceShipTwo Crashed
 
Quote:

Originally Posted by Pierre (Post 35738830)
Very true, but they were military people. Professionals involved in a cutting edge project, paid and selected for their experience and skills.

Whereas the Virgin proposition is a leisure experience, taking paying customers on a day trip.

Not too dissimilar to the early pioneer days of aviation then....and look where aviation is now. In the early days, planes (and cars too) were just rich boys toys, but of course that soon changed.

After reading todays news (which Chris linked to above) I was wishing I'd posted my comment last night. I logged in to post, wrote a long post but then deleted it. In it I doubted the engine was at fault (I used to build rocket motors years ago, not hybrid motors but I understand very well how they function) and went on a rant about press hysteria. I predicted the problem might be structurally related rather than engine nor nitrous oxide tank(s) at fault, but couldn't really be bothered with all the arguing I was expecting would ensue.
Wishing I'd posted it now after reading todays news ! Haha, oh well.

Hybrid rocket motors are actually very safe (compared with other systems), and the ideal choice when doing small, repetitive runs (of known burn time & impulse specific thrust), because they can be throttled or even switched off, whereas with solid fuel rocket motors - once ignited they cannot be stopped until the propellant is exhausted. Also, with hybrid rocket motors, the reducing agent (fuel) is a solid (can be graphite, rubber or any of most organic compounds which are solid and can withstand the conditions without breaking up). This means that there is no possibility of a fuel leak (or fuel vapours) igniting and causing an explosion/fire inside the aircraft. This is ALWAYS a possibility with liquid fuel rocket systems, which are far more expensive and dangerous to operate.
With hybrid rocket motors, as soon as the oxidiser (nitrous oxide in this case, but can be many others) pump(s) is/are stopped, the combustion and thrust ceases, so there is relatively low risk of explosion compared with other rocket systems. Also considering that nitrous oxide itself isn't actually flammable, just as oxygen isn't actually flammable.
It just rather annoyed me to see the UK press lambasting Virgin Galactics choice of rocket motor when it looked to me that they were doing everything right. But then that's the press for you.


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