[AR] Re: Another small launch company bites the dust - Aphelion Orbitals calls it quits
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Thu, 13 Dec 2018 19:18:12 -0500 (EST)
On Thu, 13 Dec 2018, Henry Vanderbilt wrote:
Looked like a middlin' hard start instantly removed the nozzle and most of
the thrust chamber, but the injector and feed plumbing did survive and
completed the run.
Insta-diagnosis, the combination may not have been as reliably hypergolic as
hoped, if enough could mix in the chamber before igniting to produce the
observed results.
A quick Googling for past work on this combination reveals an
all-too-common refrain: while ignition of ethanolamine plus a bit of
copper-chloride catalyst with peroxide might look pretty quick, when it
was actually measured, an unpleasantly large amount of catalyst was needed
to get marginally tolerable ignition delays even with a bit of fudging
(injecting the fuel hot). Now, throw in the fact that ethanolamine is
miscible with water, which is to say that it'll almost certainly be
miscible with peroxide too. Result: a combination that's just looking
for a chance to pool and form an explosive mixture when overoptimistic
people try to reduce the catalyst content to something practical.
At least they apparently were suitably cautious about it, since nobody was
hurt by their Rapid Unscheduled Disassembly Event. Takes a certain amount
of chutzpah to claim this as a successful test, though!
Pretty green flame at the end (probably a copper-based catalyst).
Henry
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