Post by Shibumi-Mandeville I-12/Hwy59 on Feb 4, 2021 16:04:53 GMT -6
So cool to have a person like Elon Musk interacting with total strangers on Twitter about SpaceX Starship.
He admitted it was dumb of them to not light all 3 raptor engines when attempting to land. They only need 2 to land with them throttled. 3 would be beyond the hover point... So they were going for 2.. but with one not lighting it crashed. There plan for SN10 is to start all 3 and shut one off after they see how they restart. Not a whole bunch of time to do all this but certainly will work if no issues beyond 1 engine flameout.
Post by Shibumi-Mandeville I-12/Hwy59 on Mar 3, 2021 7:32:02 GMT -6
Ok, today is SN10's flight attempt...not sure on timing, but if you occasionally check the feed you can see....if the checklist on the left is to the Propellant Loading stage then it's somewhere around an hour or so for launch. There is no official information to confirm...these are all based on the previous test's. .
Will this one successfully land?
SN8 launched, stalled, and control fell beautifully. The engine restart (2 of the 3 raptors firing) happened but it lost fuel feed pressure and one engine shut off causing an upright RUD (rapid unscheduled disassembly).
SN9 also launched, flew, stalled, and control fell right on target.....during the flip one of the 2 restarted engines did not fully lite and crashed more spectacularly.
Both SN8 and SN9 were relying on self-pressurized header tanks for the landing burn (separate from the main fuel tanks).
SN10 will use a separate pressure source system to feed fuel for the landing restart and burn....much like exists and existed on other rockets....probably using hydrogen.
The plan should be restarting all 3 raptor engines..then shutting down 1. This is to ensure you have 2 working engines for landing in case, like the previous test, one flames out. These will be throttled down for landing as technically only 1 engine is needed to hover....but on landing you are still killing the vertical velocity so more juice needed until just before touchdown.
Both SN9 and SN10 launched, accended, control free fell right on target to the landing pad...any placement issues were a result of the engine issues on the flip from horizontal to vertical.
Also, SN11 is getting close to completion for testing...then SN15 thru SN17 is in the works (12/thru 14 were scrapped).
This is a test program.......the unsuccessful tests are not failures...they are part of the process of learning the design, manufacture, and operation of the first time anyone had attempted what Starship is trying to do. It is largely true you learn more from mistakes than successes..especially early in a development program.
Here is my favorite Youtube space news source. They live stream and provide daily constructor videos.