The botched LASRE test program, yes. Part of the botched overall X-33
program.
The JV engineering team Lockmart put on it (after promising us their
best & brightest) didn't know enough about hydrogen to build plumbing
that would reliably contain it, so NASA Dryden sensibly refused to ever
allow the LASRE rig to be hot-fired on their SR-71.
Thus, no transonic aerospike operating data, to this day.
Henry V
On 2/12/2018 1:08 PM, (Redacted sender crogers168 for DMARC) wrote:
<< Static performance and vacuum performance of aerospike engines are well understood. Performance in trans-sonic airflow is still less so, as it's very difficult to test that without actually flying a test vehicle through that speed regime. And after all these years, still nobody has done that (that I know of.) >>
Linear Aerospike flown on the back of an SR-71 at NASA Dryden. Photos below. Essentially one-half of the X-33 body.
336155main_EC98-44440-13_full.jpg
SR-71_LASRE.jpg
Although only Helium and Nitrogen cold flow tests were done in-flight. The hot gas tests were done on the ground, but there was too much hydrogen leakage to attempt in-flight hot fire tests.
Charles E. (Chuck) Rogers
-----Original Message-----
From: Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
To: arocket <arocket@xxxxxxxxxxxxx>
Sent: Mon, Feb 12, 2018 11:10 am
Subject: [AR] Re: SSTO
On 2/12/2018 2:27 AM, Uwe Klein wrote:
> Am 11.02.2018 um 21:13 schrieb Craig Fink:
>> One solution fits
>>
>> https://i.stack.imgur.com/uKx53.jpg
>
> Compare weight of a fixed bell expansion nozzle
> and a variable geometry expansion nozzle
> that covers the the sired expansion range.
>
> Would't you be better of with a large diameter circular
> aerospike engine
> that hides behind its heatshield cum plug nozzle center?
You would, if you could be assured the trans-sonic performance of the
aerospike engine would be good enough to allow your vehicle to reach orbit.
Static performance and vacuum performance of aerospike engines are well
understood. Performance in trans-sonic airflow is still less so, as
it's very difficult to test that without actually flying a test vehicle
through that speed regime. And after all these years, still nobody has
done that (that I know of.)
Henry V
