Robert,
A couple of questions....
If you were doing it again, what would you change?
Specific questions about the design as flown...
Were all valves driven by AX12A servos?
What exactly did you use for the He pressure regulators?
What did you use for ignitor valves?
Did you do anything special to keep your ball valves tight?
A lot of times people put Belville washers on 3 pc Lox valves to keep the
valve tight as temps change?
Any seal/thermal issues with what appears to be stainless Steel ball and
aluminum body? (I could have that wrong)
Any more details on the seals in the lox ball valve?
You put purge bags around the valves/actuators..
If you were going to do it again would it be earlier to just make the
rocket body panels purge tight?
Do you have a total weight breakdown for all the components?
Again congratulations on a fantastic flight!
Paul
On Mon, Jan 17, 2022 at 6:20 PM Troy Prideaux <troy@xxxxxxxxxxxxxxxxxxxxx>
wrote:
I’d be surprised if drag played a major role in the differences (re:
Electron). Drag does scale up with the cube-square law (inversely) but
that’s providing you’re scaling down all 3 axes uniformly. If it’s still a
rather tall rocket, the geometric scaling will be mitigated. Typical
orbital class vehicles do generally have flight velocity profile that’s
quite suited for drag minimization anyway.
If I vaguely recall, the Electron does have an unusually high reliance
on its 2nd stage for complete delta V? If so, that would allow the
potential for much higher mass ratios and overall engine performance in
comparison which can skew things I suppose.
Troy
*From:* arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
*On Behalf Of *Matthew JL
*Sent:* Tuesday, 18 January 2022 12:50 PM
*To:* arocket@xxxxxxxxxxxxx
*Subject:* [AR] Re: Successful liquid launch at FAR
John - Getting off-topic but one thing that eluded me with the Silverbird
methodology was the confidence interval at the end. I wound up reverse
engineering most of it into an Excel sheet in case the site went offline
(and then putting it into a forward-calculator for building up a launch
vehicle for a given payload and propellant constraints, again for personal
use though I did wind up using it in Realism Overhaul for KSP) but I never
could figure out where the 95% CI came from. Regarding Electron - maybe
it's down to greater influence from drag rather than purely gravity losses
because the BC is smaller?
Best,
-Matt L.
On Mon, Jan 17, 2022 at 4:52 PM John Schilling <
john.schilling@xxxxxxxxxxxxxx> wrote:
On 1/17/2022 10:03 AM, Henry Spencer wrote:
On Mon, 17 Jan 2022, Matthew JL wrote:And it's long overdue for some updates; I need to get on that.
Tangent - John, if you are the same Dr. Schilling behind Silverbird
Astronautics...
Yup, he is.
Henry
Unfortunately the most-requested update is for the Electron, and I've
still not been able to come up with a model that matches their claimed
performance on that one - too many weird things going on there.
John Schilling
