And here is a video from June 2018 of a stage test using Hadley
https://youtu.be/EC28IOK03yQ
On Dec 13, 2018, at 11:52 PM, Bill Bruner <bill@xxxxxxxxxx> wrote:
Here's Ursa Major's 5K Hadley on the test stand: https://youtu.be/9UBbP5azMdY
Here's a picture of Jess holding a very early Hadley combustion chamber (we
printed it for them at my day job before they actually founded the company):
https://photos.google.com/share/AF1QipNI_GvomTezjZjUDNNW66RtqQW6_GonUztnOJWgJP82t1D4v0J2NtubhJqW5iuUtw/photo/AF1QipP-JCg9FMe9Qp_1hlceDxm38553ngtSPGrOsV5j?key=cVNSUDJCLXhjd3lXY0pCbXhzMWplTmZZbThYaEVB
Here's an ARC promo video: https://vimeo.com/214672836 ;(their engines aren't
just CGI, I have held one in my hands)
Both of these companies are the real deal, in my view.
On Thu, Dec 13, 2018 at 10:04 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx> wrote:
The reasons launch startups have tended to develop their own propulsion
would make, well, at least a chapter in a book. (Though the metaphysically
minimal answer is "AJR".) Yes, I was implicitly taking that as a given in
my advice, and at some point it needs to change.
I thoroughly approve of companies aiming to become specialized propulsion
suppliers. The industry does need that, yes. (There was a missed
opportunity ten years ago...)
How close are these two to having engines ready to go? How wise would a
launch startup be to, right now, tie its fortunes to either of theirs?
Henry
On 12/13/2018 10:46 PM, Bill Bruner wrote:
My contribution to 20-20 hindsight is - if you're a rocket company with
$500K, buy printed engines from Ursa Major or ARC.
Airplane makers don't make their own engines - that went out with the
Wright brothers.
On Thu, Dec 13, 2018 at 4:33 PM Henry Vanderbilt
<hvanderbilt@xxxxxxxxxxxxxx> wrote:
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!
Well, if you've spent your seed money and this is what you have to show
for it, you're more or less obliged to show it, think positive REALLY
HARD, talk fast, and hope for the best. Because if you didn't believe
the problems could be profitably solved you shouldn't have been trying
that in the first place.
My contribution to 20-20 hindsight here is, if you're working on a
shoestring with an untried propellant combination, you should probably
scale the initial tests WAY down - 50lbf chamber? - so the shoestring
has a better chance of paying for enough test iterations to achieve
reliable clean ignitions and burns. _Then_ you have a plausible story
to tell second-round investors about scaling it up to an operational
size engine. Going straight for the operation engine size saves time,
sure - IF everything goes right the first time.
Words for new entrants to heed and live by: Everything _never_ goes
right the first time. Plan accordingly.
Henry