So is there a lesson here for ULA re: BE-4 (or AR1, had they chosen it)?
On 2018-12-14 13:30, Ben Brockert wrote:
On Fri, Dec 14, 2018 at 12:40 PM Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:Do they come with warranties? Serious question -- if they don't, then
they aren't sufficiently fully developed for buying them to be a
no-brainer. (For a solid product, there is plenty of development work
that comes *after* the "videos of successful firings" stage.) Buying them
might nevertheless make sense, but "it's a brainer" -- a decision with
both pluses and minuses, requiring careful thought.
This is close to the problem as I see it. A launch company is willing
to launch a development rocket with development engines. The
reliability or development level of the engines can be traded against
the reliability or development level of the rest of the rocket.
You can't really do that with third party engines. If you buy an
engine you expect it to work; if you build and launch a rocket using
someone else's engines and it fails because of the engine then there
is at minimum a souring of the relationship or, more likely, a lawsuit
or insurance claim. At the same time, it makes no sense to put a
really good $2M engine on a $500k crude prototype of a stage.
There's also the issue that the engine is the hard part. Being able to
build and test an engine means you also know how to buy or build tanks
and plumbing and controls and DAQ and GSE, so you've demonstrated the
ability to make most of a rocket. There's no GNC on a test stand, but
that's a one person job on a rocket (if you hire the right person).
There's RF and maybe FTS.?utm_source=facebook&utm_medium=sw&utm_campaign=sw&fbclid=IwAR20kBmpfAQc-jFQF5Q_fQKVBNTN0eaXkiAUJeOX-oR7reFi4JNF8O1G81I
All that said, I hope companies like Ursa Major find a market and are
successful. I've met a few of them and they all seem highly capable,
and I've recommended them at more than one company now. I'm concerned
that ABL had said that they were buying from them and now say they're
building a GG cycle engine, and that Generation Orbit is using their
engine but most of the top of the company recently left to start
another company.
ARC and the other companies that spun out of the San Diego student
printed engine projects are interesting, and I'm curious where they
end up, but they're much further from delivering a complete engine.
There's a lot of focus on printing thrust chambers and little on
developing pumps.
There's also the simple problem, as XCOR found, that people who
haven't developed a complete propulsion system have no idea how much
that actually costs and will balk at a competently priced contract.
It's easy to think that a pressure fed thrust chamber demo is 50% of
the way to a good working engine, and it really really isn't.
Ben