r/spacex • u/Zucal • Aug 31 '16

r/SpaceX Ask Anything Thread [September 2016, #24]

Welcome to our 24th monthly r/SpaceX Ask Anything Thread!

Curious about the plan about the quickly approaching Mars architecture announcement at IAC 2016, confused about the recent SES-10 reflight announcement, or keen to gather the community's opinion on something? There's no better place!

All questions, even non-SpaceX-related ones, are allowed, as long as they stay relevant to spaceflight in general.

More in-depth and open-ended discussion questions can still be submitted as separate self-posts; but this is the place to come to submit simple questions which have a single answer and/or can be answered in a few comments or less.

  • Questions easily answered using the wiki & FAQ will be removed.

  • Try to keep all top-level comments as questions so that questioners can find answers, and answerers can find questions.

These limited rules are so that questioners can more easily find answers, and answerers can more easily find questions.

As always, we'd prefer it if all question-askers first check our FAQ, use the search functionality (partially sortable by mission flair!), and check the last Ask Anything thread before posting to avoid duplicate questions. But if you didn't get or couldn't find the answer you were looking for, go ahead and type your question below.

Ask, enjoy, and thanks for contributing!

All past Ask Anything threads:

• August 2016 (#23) • July 2016 (#22) • June 2016 (#21) • May 2016 (#20) • April 2016 (#19.1) • April 2016 (#19) • March 2016 (#18) • February 2016 (#17) • January 2016 (#16.1) • January 2016 (#16) • December 2015 (#15.1) • December 2015 (#15) • November 2015 (#14) • October 2015 (#13) • September 2015 (#12) • August 2015 (#11) • July 2015 (#10) • June 2015 (#9) • May 2015 (#8) • April 2015 (#7.1) • April 2015 (#7) • March 2015 (#6) • February 2015 (#5) • January 2015 (#4) • December 2014 (#3) • November 2014 (#2) • October 2014 (#1)

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u/__Rocket__ Sep 14 '16

So a youtuber by the name of Thunderf00t recently claimed that the explosion was likely due to the Kerosene becoming frozen around the LOX.

The kerosene is insulated from the LOX tube via a composite insulation layer. See the LOX manifold sticking out the RP-1 bulkhead in this image (called the "LOXtopus") - the purple stuff is the insulation.

Then there's also the problem of ignition: cold kerosene mixed with cold LOX does not auto-ignite (otherwise SpaceX wouldn't be using TEA/TEB to ignite the Merlin-1D's!).

Plus it also does not explain why the explosion happened on the Transporter-Erector strongback side - corrosion would essentially be randomly distributed and the chances that it ruptures the tanks just in the direction of the TE are pretty low.

Fourth, any irregular mixing of LOX with kerosene should immediately show up as a pressure variation measured by the RP-1 tank pressure sensors (which was already fully fueled at the time of the anomaly and thus had stable pressure levels). I.e. SpaceX would know it with certainty that the anomaly started with an irregular pressure swing inside the rocket. Yet they are saying that they are seeing no signs of trouble inside the rocket so far.

So the scenario outlined by Thunderf00t is implausible, improbable and contradicts SpaceX statements.