BUSY WEEK: Falcon9 is back in operation
• SUN early am Falcon9, Starlink FL (300th booster re-flight)
• SUN morning Falcon9, Starlink CA
• TUE morning AtlasV, USSF FL
• THU night Falcon9, Starlink FL
• FRI mid-day Electron NZ local night-time
Go full-screen
@52sec the three inner engines ignite
Fun rocket-engineering stuff (intro to exhaust shape):
• The three outer engines are optimized for on-orbit ops,
while the three inner engines are optimized for sea-level ops, i.e. landing.
• The larger expansion ratio produces low nozzle exit pressure to match atmospheric pressure in space,
so the plume gets squeezed into an hour-glass shape by sea-level atmospheric pressure in ground testing.
• The smaller expansion ratio produces a higher exit pressure that matches ground atmospheric pressure,
so it’s not squeezed and is more efficient for landing.
• Any mass not moving straight back reduces thrust and efficiency.
• Yes, this will be on the exam (slide rules only, please)
Gosh, the FAA seems to have cleared the Falcon9 to resume missions in rather short order. I wonder why that could be?
….what do you mean Starliner astronauts have overstayed their welcome at ISS……?
Yeah, might be related, eh?
Crew Dragon to the rescue?
I don’t yet know how the Falcon9 Stg2 LOX leak issue was resolved.
I’ve been keeping an eye on the thruster issue and, from what I’m reading, it sounds like Boeing is telling their astronauts the equivalent of, “Okay, we think we’ve found the issue and everything should be good to go.”
And the Boeing astronauts are saying, “What do you mean, think?”
Can’t very well burn up on reentry if Starliner isn’t even capable of getting out of orbit in a controlled manner. And I very well imagine it’s much easier to find stranded astronauts at ISS versus a small capsule moving around the earth in a decaying orbit at 25K mph an hour….(pulled the speed out of my, well, never mind)
Yeah, but it’s 17.5 Kmph for low Earth orbit
and 25 Kmph to escape from Earth’s gravity well.
Also pulled from my… unreliable memory
“Boeing astronaut”. Why does that make me giggle.
Aha! I have found you!!! 🙂
Welcome back!
(old-site evaporation is a long story for SondraK to tell, someday)
Just read that the astronauts are stuck until sometime in August (TBD):
https://hotair.com/jazz-shaw/2024/07/27/starliner-now-stuck-in-space-until-august-n3792351
Yeah,
hope they brought enough underwear
I bet that roller coaster can do 6400mph.
An oxygen sensor (that turned out to be redundant and was there for a customer’s requirements) had a line that vibrated and cracked, leaking LOX into the mylar sheeting wrapped around the control/pump area. this supercooled the TEA/TEB fluid that is used to (re)start the engine and resulted in a “hard start” of the second-stage engine – think of an internal-combustion engine backfiring and what it does to the exhaust on your car!
As a result, Mr. Engine decided to break up because a hard start usually results in a loud noise and a RUD. No Orbital Insertion. SpaceX tried to get the Starlink birds to fly themselves to orbit but the Weak Sauce ion thrusters didn’t have the oomph to do it, resulting in the loss of 23 birds.
Space is hard. And expensive. SpaceX probably lost 200+ million on the launch failure. This is a SWAG on my part…
Igor
Thanks!