On 12/13/2018 5:18 PM, Henry Spencer wrote:
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!