Rag in the LOX could detonate from turbulence during fill.
Sent from my iPhone
On Sep 10, 2016, at 10:47 AM, Rand Simberg <simberg@xxxxxxxxxxxxxxx> wrote:
That doesn't typically cause problems until post ignition, not during tanking.
On 2016-09-10 13:41, William Claybaugh wrote:
George:
Occam's razor: the Russians in the past decade have had a lot of
problems that they concluded we due to a rag left in the tank....
Bill
On Saturday, September 10, 2016, George William Herbert
<george.herbert@xxxxxxxxx> wrote:
Ok, I have a theory.
They were loading RP-1, Supercooled LOX, and GHe.
LOX tank was chilled but the Kero tank was not. Aluminum gets
stronger at cryo temps.
Partway through loading a GHe tank lets go. The flight kaboom some
time back had a full LOX tank so little space for the GHe to go,
blew the LOX tank. This time, half-full LOX tank is enough
expansion space (just) to avoid blowing the tank immediately. But
the warmer tank bottom or feed line down weren't as well chilled and
are therefore weaker, and rupture. *ping*. And pressure drops in
LOX tank.
So the LOX and GHE drop into the RP-1 tank. They don't have time to
mix much to detonable mixture. Mixture of ongoing GHE venting and
LOX boiling from the RP-1 raises combines tanks pressure again and
the warmest barrel sections, the RP-1 tank outer walls, rupture.
Possibly, a small volume reached explosive mixed conditions and
turbulence or static or impact detonates a small explosion in a
bigger mass of still mixing materials.
Some of what's ejected out is LOX - white fluffy non burnie cloud
that evaporates in the heat. Some is RP-1 and just burns. Some is
mixing RP-1/LOX and burns REALLY WELL.
When the RP-1 hoop section lets go you have say 100 PSI times pi/4
times 144 squared or say 1.6 million pounds downwards force on the
lower RP-1 tank dome and the Vacuum Merlin, held up by the
interstage. The Interstage structure fails due to gross overload,
Merlin and tank dome are forced down into Stage 1 LOX tank and
destroying the first stage.
Sent from my iPhone
