[AR] Re: SpaceShipTwo crashes shortly after Mojave test flight
- From: Paul Mueller <paul.mueller.iii@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx, Matt Dushku <mdushku@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
- Date: Sat, 1 Nov 2014 12:21:44 -0600
A very sad day for the pilot's family and all private spacecraft efforts.
Hopefully Virgin Galactic will be able to carry on.
In the third still picture in the NY Daily News article, it looks like the
motor had been burning normally for at least a short period of time after
ignition. The smoke trail from SS2 looks like it went from grayish to a
brighter white in this picture. It could be:
1) lighting artifact (though I doubt there were any clouds higher than
50,000 feet that could cast a distinct shadow on the smoke trail)
2) a normal part of ignition/the initial burn (I don't know their ignition
method)
3) an indication of an abnormal burn:
a) something burning in the motor that wasn't supposed to
b) some change in the oxidizer flow due to valve or injector
malfunction
c) any number of other things
The oxidizer tank doesn't look ruptured from the pictures I see. The "big
white puff" is probably the nitrous being vented. I doubt any relief valve
could dump it all so quickly. It seems to me the only way to get all that
nitrous out so fast (without rupturing the tank) is for the injector to
have failed (ruptured or broken loose or both). Maybe there was a short
period of anomalous motor operation (the whiter smoke trail) and then the
injector failed due to this. If a large amount nitrous were dumped into the
motor, I could see it exploding due to simple pressure effects (typically
motor cases aren't designed for as high pressures as the oxidizer tanks
are, but I don't know any details on the SS2 design), possibly enhanced by
a nitrous dissociation reaction .
I have some experience with nitrous hybrids but this is definitely all
conjecture based on a couple of photos.
Paul M
On Sat, Nov 1, 2014 at 7:13 AM, Thom Vincent <sworkeld@xxxxxxxxx> wrote:
> NBCNews has a video clip interviewing Ken Brown, who was on-site. He said
> there was just a big "puff" .... "a big white puff". His still pic of the
> white puff are in the video and in a NY Daily News article.
>
>
> http://www.nbcnews.com/science/space/spaceshiptwo-shattered-what-we-know-about-rocket-planes-fatal-flight-n238896
>
>
> http://www.nydailynews.com/news/national/virgin-galactic-spaceship-crashes-test-flight-article-1.1994672
>
> ~Thom
>
> On Fri, Oct 31, 2014 at 5:25 PM, George Herbert <george.herbert@xxxxxxxxx>
> wrote:
>
>> Just FYI this has been widely Tweeted about in realtime:
>>
>> @spacecom / Doug Messier was on the ground below the test and saw it
>> happen, and debris and a body on the ground.
>> @jeff_foust
>> @Rand_Simberg
>> ...among others.
>>
>> George William Herbert
>> Sent from my iPhone
>>
>> On Oct 31, 2014, at 1:30 PM, Ian Woollard <ian.woollard@xxxxxxxxx> wrote:
>>
>> The report I saw somewhere or other was that the engine started, stopped,
>> restarted and then exploded.
>>
>>
>> On 31 October 2014 19:18, Redacted sender JMKrell@xxxxxxx for DMARC <
>> dmarc-noreply@xxxxxxxxxxxxx> wrote:
>>
>>> NBC stated Scaled Composites was testing the new plastic fuel to
>>> replace the HTPB.
>>>
>>>
>>>
>>> In a message dated 10/31/2014 11:50:45 A.M. Pacific Daylight Time,
>>> ian.woollard@xxxxxxxxx writes:
>>>
>>>
>>> http://www.kerngoldenempire.com/news/local/story/d/story/spaceshiptwo-crashes-shortly-after-mojave-test-fli/11401/64VdLqg21EWpK1vuptvTsg
>>>
>>> Unfortunately, the reports so far are that there's been a fatality.
>>>
>>> --
>>> -Ian Woollard
>>>
>>>
>>
>>
>> --
>> -Ian Woollard
>>
>>
>
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