Virgin Galactic incident

[Dr Jekyll]

An 'in flight anomaly' apparently. Worrying to say the least.

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

[essayer]

Not good, how many crew does it have?

[Dr Jekyll]

Don't know, apparently 2 chutes spotted.

http://news.sky.com/story/1364455/virgin-galactic-...

[hornetrider]

More here

http://www.telegraph.co.uk/news/worldnews/northame...

Two pilots.

[Civpilot]

Rumour of 1 facility coming out (just reported on BBC news 24)

Hopefully untrue

[Rower]

Very sad news indeed .

Listening to the radio this morning where the whole scheme was being discussed It was said that this engine was using different fuel as prior to this the fuel was 'rubber' . Can anyone explain how that works .....

[Dr Jekyll]

Rower said:

Very sad news indeed .

Listening to the radio this morning where the whole scheme was being discussed It was said that this engine was using different fuel as prior to this the fuel was 'rubber' . Can anyone explain how that works .....

HTPB, better described as synthetic rubber.
http://aeroconsystems.com/cart/motor-making-suppli...

Mix it with nitrous oxide and it burns rapidly, which is all rocket fuel needs to do. The HTPB is solid but the nitrous oxide is liquid and can be throttled giving the kind of control impossible with a pure solid fuel rocket.

The new fuel is plastic, similar to nylon I think, but still solid and used with nitrous oxide.

[Eric Mc]

Been away from the internet and TV over the past two days so was not able to follow this news story apart from the radio news reports. It looks like they were using a more powerful version of the hybrid solid fueled motor that they had been using up to now and that something went wrong just after ignition which broke the machine up.

[dr_gn]

Nothing to do with the propulsion system - apparently:

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

I don't get why deploying it at "Mach 1" would cause a disaster, yet if deployed at "Mach 1.4" it's normal.

[Eric Mc]

Being discussed all over PH at the moment. It's hard to follow all the threads.

This is the quietest one.

Definitely looks like it wasn't an engine issue. Like Challenger years ago, what witnesses were describing as an "explosion" wasn't an explosion at all.

[hornetrider]

dr_gn said:

I don't get why deploying it at "Mach 1" would cause a disaster, yet if deployed at "Mach 1.4" it's normal.

Lower altitude and thicker air at the Mach 1 stage of the flight?

[dr_gn]

hornetrider said:

dr_gn said:

I don't get why deploying it at "Mach 1" would cause a disaster, yet if deployed at "Mach 1.4" it's normal.

Lower altitude and thicker air at the Mach 1 stage of the flight?

Maybe, but they only mentioned speed in the press conference, rather than altitude. I assumed speed was the defining factor for safe operation.

[Simpo Two]

dr_gn said:

I don't get why deploying it at "Mach 1" would cause a disaster, yet if deployed at "Mach 1.4" it's normal.

Perhaps because its already gone through the sound barrier attached to the mothership? Totally different parameters.

[Eric Mc]

I don't think it has. I'm pretty sure the mothership is subsonic only.

[Dr Jekyll]

dr_gn said:

Nothing to do with the propulsion system - apparently:

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

I don't get why deploying it at "Mach 1" would cause a disaster, yet if deployed at "Mach 1.4" it's normal.

Deployed at 1.4 isn't normal. The point is that they can unlock it at 1.4 without the danger of it deploying on it's own, at less than that the airflow can deploy it. It's unlocking it at Mach 1 that's the issue.

[Simpo Two]

Oh right, deploying a feathering system. I thought you meant deploying the craft.