Scivillage.com Casual Discussion Science Forum

Elon gave a presentation to SpaceX workers at Starbase a couple of days ago, with lots of information-nuggets. One was an explanation of why Ship 25 blew up during IFT-2 after it had achieved ~90% of orbital velocity.

Turns out that it wasn't a hardware failure as many had hypothesized. (A big plume of vapor was observed around the ship before it exploded, prompting speculation about fuel tank ruptures.)

What happened is that the ship had begun venting excess LOX as it approached orbital velocity in a preplanned maneuver intended to lighten the ship's mass and improve its orbital parameters. And that LOX unexpectedly interacted with the engine exhaust plume and swirled back into the engine skirt, causing an explosion.

Elon said that ironically, the problem wouldn't have occurred if the Starship had been carrying a payload, since all the LOX would have been consumed in that case, making the dump-maneuver unnecessary.

It's an easily fixable problem, just requiring some software changes to the fight computer. Elon says that they are increasingly confident about IFT-3 achieving orbit in February (hopefully).

Elon said that the agenda for IFT-3 is achieve orbit, open and close the cargo bay door in orbit, start to demonstrate propellant handling in orbit by transferring fuel to and from the headers and main tanks (this is a HLS milestone) and demonstrate deorbit burn.

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And at Starbase, one big event was removal of two of the eight big vertical propellant tanks at the Orbital Tank Farm. One of the two tanks was intended to be a water tank, but was never used because it was discovered to leak. It was badly dented by IFT-1's concrete holocaust, so they pulled it. The other tank pulled was originally intended to be a methane tank, but repurposed to hold water after it was discovered that its design didn't conform to Texas hydrocarbon storage codes. Both tanks that were removed were immediately scrapped.

The other big event was the tearing down of the third of the giant tents, after its nosecone fabrication function was moved into the ever-growing Starfactory. This leaves only one giant tent left, the parts-inventory tent in Sanchez on the far side of the vertical assembly bays. (Containing racks and racks of parts, like a giant Home Depot for spaceships!)

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What's more, SpaceX is starting to make use of more of the properties it purchased stretching several miles in the westward Brownsville direction. The most prominent of them is the former Massey's shooting range, now repurposed into a cryo-pressure testing site and perhaps a ship static fire site in the future. Elon's Ad Astra school is out there on another site near the Massey's turnoff. There's a large area further east that's been cleared and appears to be used for storage so far. And this on yet another site....



Given all the new housing going in at Boca Chica, everyone has been expecting some retail so that workers don't have to drive all the way into Brownsville (~15 miles) to pick up groceries. These new facilities will still be a ways away from Boca Chica, but will be much more convenient. (Everyone is exclaiming about seven employee parking spots, seems awfully few. Maybe they mean seven employee Tesla chargers.)

Here's a map showing the location (at the red marker). The oval on the lower left by the Rio Grande is Masseys. In the upper left is Ad Astra School on hwy 4 just to the right (E) of the Massey's t-junction. SpaceX's proposed little shopping/dining development is along the river to the east. Starbase is off the map to the upper right a mile or so. And along the Rio Grande to the right at Tarpon Bend are privately owned (non-SpaceX) Rocket Ranch and Starship Station where space-nuts can rent accomodation or camp. All the engineering nerds, live-streamers, photographers and space journalists will be there for launches, so it's great for meeting people. These are the closest viewing spots to Starbase (on the US side, anyways) from which to view launches. Everyone's shared passion makes it like a big excited family, highly recommended, but they fill up quickly on Starship launch days. Book ahead online.

Excellent article about Elon's presentation by Stephen Clark in Ars Technica.

https://arstechnica.com/space/2024/01/el...ting-news/

Excerpts:

Musk said SpaceX is working on extending the life of Falcon 9's reusable first-stage boosters. Originally, SpaceX said each Falcon 9 booster could fly up to 10 times without a major overhaul. Some Falcon 9s have now flown almost twice that number of missions.

“We’ve done a 19th re-flight," Musk said. "We’re now qualifying Falcon 9 to be able to do 40 flights... We’re aiming to hopefully, I think, get under 24 hours pad turnaround by the end of this year," Musk said.

Regarding Starship...

"Flight 3, we want to get to orbit and we want to do an in-space engine burn from the header tank and prove that we can reliably de-orbit," Musk said. "We want to do a Tipping Point header-to-main propellant transfer. This is important for the NASA Artemis program. And we also want to demonstrate the payload door for the ... Pez dispenser for delivering the Starlinks."

SpaceX is constructing a second Starship launch pad at Starbase in South Texas. "We’re going to really be launching a lot, and we’re going to be upgrading one tower while we’re launching from another tower, so two towers is important," Musk said.

The human-rated Starship lander, the Starship depot, and Starship tankers will all launch on top of Super Heavy boosters from sites in Texas and Florida. This is an immense challenge. SpaceX has demonstrated its ability to dock spaceships in orbit, but no one has ever transferred meaningful amounts of cryogenic propellants in space before. Musk said he's confident SpaceX can do it.

(Jan 14, 2024 08:13 PM)Yazata Wrote: [ -> ]What's more, SpaceX is starting to make use of more of the properties it purchased stretching several miles in the westward Brownsville direction.

Here's more - SpaceX is proposing to the Texas state parks to trade 477 acres that the company owns adjacent to the Laguna Atacosa national wildlife refuge for 43 acres of Boca Chica state park adjacent to the build site and the launch site.

It comes up for consideration on January 25, 2024 and the recommendation is that it be approved since the Texas state parks get 434 more acres than they are giving up and both parcels are equally valuable as endangered species habitat.

https://tpwd.texas.gov/business/feedback...m=9#09_exd

Starbase is well on its way to becoming a real place:

"The Brownsville City Commission has officially supported renaming the area east of Brownsville, Texas, to "Starbase," echoing Cameron County's resolution. This decision was formalized at the Commission meeting on December 12, 2023.

Located off Texas Highway 4 and approximately 20 miles east of Brownsville, "Starbase" is notable as the location of SpaceX's commercial space launch sites, marking it as a significant site in the realm of space exploration.

Brownsville Mayor John Cowen Jr., in a letter to the U.S. Board on Geographic Names, U.S. Geological Survey, expressed the city's endorsement of this name change."

https://www.brownsvilletx.gov/CivicAlerts.aspx?AID=1729

Photo (screenshot by Vicki Cocks from Lab Padre's Rover 1 livestream cam) showing the new nosecone assembly hall under construction at the Starfactory. It's bigger than it looks, maybe 5 stories tall. When complete, it will connect with the existing nosecone assembly hall at the right which is already in use to create a huge U-shaped building. Then it will extend into the space vacated by the giant tents where the yellow excavators are visible working on foundations, linking with the existing portions of the factory in the background to fill in the center of the U. It will be a certifiably massive squarish structure when it is complete.

Starship art at the Brownsville/South Padre Island International Airport

https://twitter.com/Daniel_S_Images/stat...1616345533

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And an FAA spokesman confirms that SpaceX has submitted their 'mishap investigation' into why IFT-2 didn't achieve orbit as planned and has requested an amended launch license for IFT-3. Speculation is still that IFT-3 will happen around the middle of February.

The latest photo of the new factory construction. The nosecone assembly hall looks to be widening out both to the right (towards the road) and to the left (where new building is expected to eventually fill the entire space back to the existing factory building in the background.)

Screenshot from Lab Padre's Rover 1 livestream cam by the inimitable Vicki Cocks

People who have been following Starbase for a long time might remember Austin Bernard. He was a young Brownsville local kid known for his enthusiasm and for his determination to someday be a Martian, who made twitter posts and the occasional video about events in Boca Chica back in the Hoppy days. Then he said that he was going to apply for a job at SpaceX and kind of dropped out of sight.

Well here he is! The tiny speck in the circle on this photo! Photo appears to be from Lab Padre's Sentinel cam livestream, with the circle drawn in by Austin, who is now a member of what SpaceX'ers call the "booster tribe", the workers who build the boosters.

Even the skies proclaim it!



Screenshot from Lab's Rover-2 livestream cam by Vicki Cocks.

Aviation Week, the leading aerospace trade publication which is usually very well informed, is reporting this...

"The Pentagon has approached SpaceX about potentially taking over Starship for sensitive and potentially dangerous missions as a government-owned, government-operated asset instead of contracting the company to launch payloads..."

"...In this hypothetical case, the military could take a Starship off the line for a specific mission and return it to SpaceX after it is complete..."

Apparently in most normal situations the procedure would be to simply buy commercial Starship service from SpaceX. But the DoD anticipates specialized use cases (military combat for instance?) where use of a military vehicle would be more appropriate both for the military and for SpaceX.

SpaceX says they are studying the proposal.

https://aviationweek.com/defense-space/s...l-missions