Back during the Nov. 18 launch of Starship integrated flight test 2, we saw the booster explode after stage separation and then heard or read that the Starship itself also was lost just about at the end of its burn to reach its suborbital trajectory to the Pacific. There were reports that the autonomous flight termination system was activated, but no explanation of why in the nearly two months since.
That lack of explanation was fixed by Elon Musk at a State of the Company All Hands meeting on Jan.12 and posted to social media.
At a recent event at SpaceX’s Starbase test site in Boca Chica, Texas, video of which SpaceX posted on social media Jan. 12, Musk said the failure was linked to venting liquid oxygen propellant near the end of the burn. That venting, he said, was needed only because the vehicle was not carrying any payload.
“Flight 2 actually almost made it to orbit,” he said. “If it had a payload, it would have made it to orbit because the reason that it actually didn’t quite make it to orbit was we vented the liquid oxygen, and the liquid oxygen ultimately led to a fire and an explosion.”
I've seen the hour-long talk is there as a video on YouTube but naturally can't find it right now to link to, but that link to X looks to be the same video and you probably won't get inundated with commercials.
Returning to the story, Musk went on to say, “I think we’ve got a really good shot of reaching orbit with Flight 3.” Flight 3 is projected for February, dependent (as always) on a launch license from the FAA.
“We want to get to orbit and we want to do an in-space engine burn from the header tank” at the top of the vehicle, he said. Doing so would “prove that we can reliably deorbit.”
The flight would also test transferring propellant from that header tank to the main propellant tank, a demonstration that is part of a NASA Tipping Point award as a milestone towards transferring propellant from one Starship vehicle to another. The first ship-to-ship propellant transfer test is planned, he said, “hopefully by the end of this year, but certainly by next year.”
Musk said SpaceX will test the “Pez dispenser” payload door that will be used on later flights to deploy the full-sized Starlink V2 satellites, significant larger than the V2 mini satellites currently being launched on Falcon 9. “We do hope to do this by the end of this year,” he said of launching Starlink V2 satellites.
Starship and SuperHeavy lifting of for IFT 2 on November 18th. Credit: Trevor Mahlmann for SpaceNews
Let me add a short update on the Peregrine mission. SpaceNews is reporting today that Peregrine's trajectory is being affected by the leakage of fuel that ruined the mission.
“Our analysis efforts have been challenging due to the propellant leak, which have been adding uncertainty to predictions of the vehicle’s trajectory,” the company said in a statement. “Our latest assessment now shows the spacecraft is on a path towards Earth, where it will likely burn up in the Earth’s atmosphere.”
Independent analysts JPL Horizons, using available tracking data, estimate a reentry over the Great Barrier Reef late on January 18 - in the vicinity of 2230 to 2300 UTC or 5:30 to 6:00 PM US EST Thursday. The variation in the leakage may put more uncertainty in that time than usual, although it appears the leakage has become less variable as the amount leaking has gone down. “The propellant leak has slowed considerably to a point where it is no longer the teams’ top priority,” Astrobotic said in its Jan. 13 update. They didn't specifically address whether they know if the craft will be out of propellant before it burns up on reentry.
Is the damn thing leaking, like "drip, drip" or is it leaking while under pressure - aka venting? Venting would affect the trajectory, a "drip, drip" not so much. I predict it will be out of propellant after it burns up on reentry.
ReplyDeleteCP
Leaks don't "Drip drip drip" in space nor in microgravity.
DeleteThe tank got overpressurized, a seam or fitting broke open (most likely cracked), the prop is venting - acting like a very unpredictable jet of oxidizer. As the pressure goes down, the leak gets smaller and the jet affect goes down as well. Hard to predict exactly how much delta-vee it will eventually impart to the spacecraft, so it's a SWAG where it will come into the Earth's atmo.
Igor my sarcastic comment was directed at the idiot who used the word leak, in a press release, rather than the more appropriate word “venting. I’m familiar with these types of propulsion systems and their failure modes. The tanks, though very thin walled, tend to have robust welds at their welded seams. The thin walled tubes welded to the tank inlet and outlet can be problematic If not done correctly and properly inspected.
DeleteCP
There's rumors going around that they may launch a few V2 Starlink birds, but we haven't seen them install a PEZ dispenser in any ship yet - it has to be done before the put the nosecone on, and none have been observed with it in. Maybe around IFT 5 or 6 or so. Also, S26 may be used for orbital propellant depot tasks/test, we shall see. Soon, I hope. I have a few ideas how the ship-to-ship transfer MAY work, but brighter minds than mine have been working on the process for a few years now and I may be totally off base. I'll keep my opinions to myself.
ReplyDeleteStay tuned ! Excitement guaranteed !!
Latest from Astrobotics is they are going to deorbit somewhere over the Great Barrier Reef - *IF* the leak doesn't add too much perpendicular thrust to the flight path. Thursday, late. Local time??
ReplyDeleteBummer.