Elon is a fan of the "Build it, run it, break it, fix it, run it again",
rinse and repeat approach.
For much of engineering history that I recall, that was "Standard
Operating Procedure"...
But yeah, part of the engineering data they appear to be getting is
about the Raptor design. There's a world of difference between getting
one to run on a stand and in a steady state "hop". And an equally large
jump from that to starting and stopping them while involved in energetic
vehicle maneuvers.
John
On 3/4/2021 12:45 AM, roxanna Mason wrote:
These Raptor engines sure seem to be fragile when outside of their operating envelope regardless of the fact that's usually the case with any engine of its kind.
Seems like a long way to go before a Starship screams into the Martian atmosphere with 100 people on board.
"You're not learning if you're not crashing regularly" right?
K
On Wed, Mar 3, 2021 at 8:43 PM Thomas Janstrom <thomas@xxxxxxxxxx <mailto:thomas@xxxxxxxxxx>> wrote:
In this case I'm not so sure we can say "good or not so good"
these motors are copper alloy and don't use the hypergol that the
falcons use that gives a transient green flame on start up. That
just leaves over heating/oxidising copper as the colorant. Neither
are good for a reusable motor I'd say.
Thomas.
On 4/03/2021 2:36 pm, Anthony Cesaroni wrote:
Hi Ken,
Green can be good or not so good, How are the students making out
with the 7-Up motor I sent out? Is the motor ingratiated, cold
flow tests yet?
Thanks
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/ ;<http://www.cesaronitech.com/>
(941) 360-3100 x1004 Sarasota
(905) 887-2370 x222 Toronto
*From:* arocket-bounce@xxxxxxxxxxxxx
<mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx>
<mailto:arocket-bounce@xxxxxxxxxxxxx> *On Behalf Of *roxanna Mason
*Sent:* Wednesday, March 3, 2021 11:25 PM
*To:* arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
*Subject:* [AR] Re: SN-10 launch attempt imminent?
Green flames can not be good even if intentional if you want
reusability. The flight regime appears good though, the part of
the mission that should have been the most problematic. So again,
Go SpaceX!
K
On Wed, Mar 3, 2021 at 8:07 PM Thomas Janstrom <thomas@xxxxxxxxxx
<mailto:thomas@xxxxxxxxxx>> wrote:
Several observations from the footage available:
Firstly the land legs didn't lock into position
That landing was HARD, there was at least a meter worth of
bounce, notice the transition from the nose to body crumpled.
There was likely quite a bit of impact related damage to the
plumbing given the forces involved
Pooling Lox+Lmethane in a confined space is always a bad
thing, the detonable range is just so huge and requires
almost no input energy to ignite, a warm rocket engine will do.
During flight one engine was running oxidiser rich (greenish
flame) and another fuel rich whether this was intentional or
not we might never know.
So yes it landed and thats a big success but they need to
work on those legs, they have been a potential issue since SN5.
Thomas.
On 4/03/2021 1:56 pm, roxanna Mason wrote:
Did they totally shut down all electrical systems that
could be an ignition source, or is it hopeless having
oxygen and methane intimately mixed?
Reminds me of the DCX when it blew up after a landing
gear failure.
K
On Wed, Mar 3, 2021 at 7:31 PM J Farmer
<jfarmer@xxxxxxxxxxxxx <mailto:jfarmer@xxxxxxxxxxxxx>> wrote:
It was sitting at a tilt after landing. Apparently
the landing gear has been a concern. My supposition
was that one or more didn't extend or lock on extension.
My first thought after the explosion was that the
landing gear failure caused a slow methane leak.
That seemed to be born out by the extended hose down
of the vehicle by the ground crew.
John