[AR] Re: SpaceX (was Re: arocket Digest V4 #217)
- From: Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Sun, 11 Sep 2016 17:40:00 -0700
On 9/11/2016 3:56 PM, David Weinshenker wrote:
On 09/11/2016 03:43 PM, Henry Vanderbilt wrote:
Yes, but... As I understand it, aluminum in LOX very much tends not to
catch fire absent significant heat and/or a mechanical impact or tear
that exposes unoxidized aluminum directly to LOX.
Something fractured (or jammed violently and made fresh scratches /
shavings) in a vent valve handling pressurized GOX?
Any GOX in a vent valve would, I think, have been at relatively low
pressure at that - at any - point in the process. It's a pump-fed
lightweight stage; I'd be surprised if system pressure is ever supposed
to be more than some tens of psi. Metal's tendency to catch fire in GOX
scales significantly with pressure. (Density related?)
This doesn't rule out a valve failure such as you postulate as a source
of the initial energy, but it may make it relatively less likely.
It also suggests the possibility of a similar valve problem on the LOX
loading side as a source of the initial energy.
It looked like the venting plumes of cold vapor changed location
shortly before the burst, in the video I saw (not sure if that's
relevant)...
Do we know anything about exactly where the second stage was in the
propellant loading process? Just starting, steady-state loading, just
finishing, some other transition within the process?
If some sort of unscheduled transition happened in the venting, that
could be very relevant.
Henry
Other related posts:
