In conjunction with the issuance of the Starship launch license to SpaceX, on 2023-04-14, the U.S. Federal Aviation Administration (FAA) updated their “SpaceX Starship Super Heavy Project at the Boca Chica Launch Site” document. That document announced the release of a (deep breath) “Written Re-evaluation of the 2022 Final Programmatic Environmental Assessment for the SpaceX Starship/Super Heavy Launch Vehicle Program at the Boca Chica Launch Site in Cameron County, Texas” [PDF, 122 pages], which is subtitled (another deep breath) “Starship/Super Heavy Vehicle Ocean Landings and Launch Pad Detonation Suppression System”.
The document analyses, in excruciating detail, the possible consequences of the Super Heavy booster and Starship upper stage splashing into the water off the coasts of Texas and Hawaii, respectively, both for a nominal mission and a Really Bad Day for one or both.
The mechanism of explosion after a Starship impact with the ocean at terminal velocity and its coupling to the ocean and noise propagation is discussed at great length.
The report then discloses that if the first Starship flight is successful, the plan is for the second and third flights to expend the upper stage with no plan for its surviving re-entry. These will presumably use the Starships observed at Boca Chica which have no thermal protection system tiles attached.
For the second and third flights, after separation from Super Heavy, Starship’s engines would start and burn to the desired orbit location. Upon reentry, Starship is expected to break up and SpaceX proposed an area southwest of Hawai’i, to account for the potential Starship debris field. The area of the debris field is determined by performing a debris analysis for an uncontrolled Starship entry. In this scenario, the vehicle enters the atmosphere uncontrolled and breaks up above 70 kilometers above ground level and the resulting debris is propagated through the atmosphere to impact in the North Pacific Ocean. The locations of debris impact are then bounded to generate the debris field area. It is theoretically possible for debris to land outside of this area, but the debris area shown is representative of a nominal uncontrolled entry based on flight modeling. As Starship slows down during its landing descent, any noise from vehicle break up would be imperceptible because Starship will be at such a high altitude (at the edge of the atmosphere). Water depth at the debris field area is approximately 4,570 meters deep.
It’s dawn in Texas, and SpaceX is chilling the propellant lines with liquid nitrogen prior to beginning propellant flow to the Super Heavy booster and Starship upper stage. (2023-04-17 11:35 UTC)
While I earnestly hope for success, the mere design and building of Starship already constitutes a rare and worthy set of events. The impulse to build it and the organized, voluntary efforts of thousands of competent individuals, reflects some of humanity’s best attributes. It is truly sad that so much recent effort of the power elites has gone toward the unworthy goal of enslaving the rest of us. To reminisce, I’ll say “Godspeed Starship”! Thanks to Elon Musk for doing what he was likely (internally) compelled to do in the first place.
The SpaceX Webcast is now live. Propellant load is underway, with around half an hour before scheduled launch time.
Launch has been cancelled for today due to a pressurisation problem with the first stage. The fueling and countdown will continue until the T−10 second mark, serving as a full wet dress rehearsal right up to the moment before engine ignition. Afterward, propellant will be unloaded for a recycle for the next attempt.
Minimum recycle time after a scrub is 48 hours, due to the need to re-condition the propellant for loading.
One notable example was American Rocket Company’s (AMROC) SET-1 launch attempt on 1989-10-05. This was a suborbital test flight of one of the hybrid rocket (solid fuel, liquid oxygen oxidiser) cores which were to make up its Industrial Launch Vehicle (ILV) called SET-1 (Single Engine Test 1). Burns of the engine had been performed on the test stand at Edwards Air Force Base in the California high desert, but in the humid atmosphere at the Vandenberg Air Force Base launch site an ice plug formed under the main liquid oxygen valve restricting its flow to less than needed to lift off. The rocket burned on the launch pad and the company never recovered from the failure and shut down in 1996.
The question is why didn’t this show up in prior tests?
Is it that prior SpaceX tests were at less humid times of day? Did the rocket collect morning dew?
Valves can stick for all kinds of reasons—humidity freezing on them is just one of many potential causes. As I recall, one of the SLS wet dress rehearsals ran into a stuck valve which would have scrubbed the attempt if it hadn’t already been scrubbed due to other problems. Sometimes you can fix a stuck valve just by whacking it with a wrench, but with the pad closed for launch that isn’t an option.
Yeah, that one really got to me. I don’t now recall the other frozen LOX valve failures but it was sufficient to get me to bring up the specific problem with the late Andy Cutler during our work on space commercialization legislation. It just struck me as weird that people weren’t learning from this particular history of failures. Andy said that it made sense to dedicate one LOX-valve specialist engineer, full time, to nothing but making sure there would be no LOX valve failure.
A new launch window has been announced for the Starship Orbital Flight Test: 2023-04-20 with the 62 minute window opening at 13:28 UTC and closing at 14:30 UTC. I have updated the Webcast player in the main post for this launch attempt.
Somehow, you just knew it was going be on 04-20.
On 2023-04-16, the evening before the first Orbital Flight Test, Elon Musk held a 45 minute Twitter Spaces audio conversation with a variety of space journalists.
“If we do launch, I would consider anything that does not result in the destruction of the launch pad—stage zero, effectively—I would consider that to be a win.”
He goes on to note the similarities between Super Heavy/Starship and the Soviet N1 Moon rocket.
This is a superb deep dive into the expectations for the test flight, the difficulties in getting this far, and what comes next depending on the outcome of the test.
The Temporary Flight Restriction (TFR) for a Starship launch on 2023-04-20 has been withdrawn, and new TFRs issued for 2023-04-23 through 2023-04-25.
(The TFR for the 24th has been posted on the FAA Web site, but due to a formatting error, was not rendered by the automated Space TFRs
Once again early morning…
They haven’t said. A Temporary Flight Restriction (TFR) had been filed for the 20th, but was withdrawn. However, on the live coverage of the Starlink launch, they just said it was still possible for a launch on the 20th, and the Starship Orbital Flight Test page on the SpaceX site still says:
SpaceX is targeting as soon as Thursday, April 20 for the first flight test of a fully integrated Starship and Super Heavy rocket from Starbase in Texas. The 62 minute launch window opens at 8:28 a.m. CT and closes at 9:30 a.m. CT.
So I dunno what’s going on or what they’re smoking there. Maybe the 20th date is just a token gesture.
And…the TFR for 2023-04-20 is back up on the FAA site: NOTAM Number: FDC 3/3446.
The SpaceX Webcast is now live, half an hour before the start of the launch window.
They say that the reason for the scrub on the 17th was due to moisture in a valve in the autogenous pressurisation system which froze when cryogenic fuel was loaded.