SpaceX Starship and Super Heavy: 120-meter stack tested

[gleem]

Is it known why the plate is oriented at a right angle to the exhaust as opposed to an acute angle so as to deflect the exhaust more effectively?

 

[mfb]

The right angle could come with a lower heat load, keeping the boundary layer of evaporated water there a bit more efficiently. You have this effect in reentry heat shields where a relatively blunt front sees a lower heat load than a spike design. It's definitely lowering the peak heat flow in the center. It's also better in terms of sound.

 

[mfb]

Assembly of the water-cooled steel plate makes progress. The water pipes are gigantic:



Meanwhile Starship SN25 is moving, likely to the launch site for testing. For ships there is a separate test stand, so SN25 doesn't need the orbital launch mount that is being repaired.

 

[mfb]

SpaceX blasted a water-cooled steel plate test article with a Raptor exhaust at their engine test facility:

 

[mfb]

Ship SN25 completed its static fire test, it's likely ready for a flight or at least will be ready well before other components.

The center of the water-cooled steel plate has been installed under the launch mount.
Here are some renders showing how it's getting water.
Once they are done with the launch mount they can put the booster on top and start its test program. That will likely take a few weeks, too.

 

[gleem]

After the launch of Starship Musk said that the second launch would probably occur several weeks after the completion of the modification of the OLM which should be occurring shortly. Also, ship N25 seems ready to go.

Is there any significance of the reluctance of SpaceX to post a tentative/possible launch date as late summer or August TBD, etc.?

 

[mfb]

Too much schedule uncertainty, I think. They will have some plan for the launch mount and booster test campaign but they also need to finish the accident investigation, get FAA approval, and likely need the current lawsuit against the FAA closed.

 

[.Scott]

I'd been under the impression that the water deluge was more/exclusively for sound abatement. Maybe they calculated they didn't need it.

According to SpaceX statements made after the launch attempt, they knew they had to change it and were preparing to do so. They calculated that what they had would be good for one launch.

So they were off by 1.

 

[gleem]

Well the OLM water deluge system has be completed and tested.

 

[Rive]

Well the OLM water deluge system has be completed and tested.

That poor bird there

 

[mfb]

Booster 9 has arrived at the launch site. Launch tower repairs and upgrades must be almost done. About 1 month time to test the booster, a bit of full stack testing and SpaceX might be ready for a launch in late August or early September, pending regulatory approval.



Edit: Booster has been lifted onto the launch mount. A lot of new shielding around the engines.

 

[mfb]

Water deluge system at full power.

The sound is loud 13 seconds into the video.



Different view:

 

[mfb]

They performed a 33 engines static fire test. Out of these 4 shut down early and the test was stopped after 2.7 seconds instead of the intended 5 seconds.
No obvious damage besides a fence that got knocked over. The last time that many engines fired we had a crater below the launch pad, although they fired for longer at that time.
Livestream

Looks like they still need more work on the engine reliability. You don't want to take off with 29 engines - it can be enough to reach orbit but it would reduce the safety margins significantly.

 

[mfb]

SpaceX has submitted its final accident review of the first orbital flight test to the FAA.
The FAA will respond with a list of things SpaceX has to change before the second flight. Once SpaceX has implemented all of them FAA can approve a second launch.

They have worked together closely during the accident investigation so these final reports are generally not surprising either side. It's very likely SpaceX has already implemented many of the changes the FAA wants.

 

[mfb]

Second static fire of booster 9 could happen within minutes.

Edit: Completed. 5-6 seconds at 50% thrust as planned.

 

[mfb]

Starship has been stacked. Musk tweeted (Xed?) "ready to launch, awaiting FAA license approval" but that likely just means they expect to get ready before they get the approval.
For the first flight, stacking was followed by a wet dress rehearsal (WDR), then they unstacked the ship to prepare the flight termination system (FTS) and restacked. It's possible they'll work on the FTS with a stacked ship now and they *might* skip the WDR, but as they don't have an approval to launch yet we could see more tests.

 

[mfb]

FAA Closes SpaceX Starship Mishap Investigation

63 corrective actions identified - most of them will have been developed and already implemented by SpaceX. They are probably done or already done with the list. SpaceX has to declare that they are done, FAA has to accept that, then they can work on a second flight.

 

[mfb]

We got the list (copy here), and SpaceX says they are done with 57 of them, the others are items for later flights:



Now the FAA needs to review that and agree, then they can approve a second flight.

 

[.Scott]

This list was not made public immediately because it contained proprietary and ITAR data. No doubt, that's the reason that all items on this list are very circumspect.

 

[mfb]

Oh sure, that is an edited version of the original list to remove all ITAR-relevant and critical proprietary information.

 

[gleem]

Thirteen Years of Florida SpaceX launches is a one-minute video.

https://www.msn.com/en-us/video/web...64419d520a54ed4ae808218c1c4bb3e&ei=96#details

 

[mfb]

Doesn't load for me, but with ~200 launches it must be a mess.
Here is a 4 minute video. It's already very busy, and it doesn't include most of 2023. SLC-40 in particular (the farther launch site in the video) launches like it's a train schedule this year, every 4-5 days unless the weather is bad or it has to hit a launch window. September 16, September 20, September 24, September 30, October 5, October 13, with plans to launch October 17, 21 and 26.

 

[gleem]

here is another link to this video

 

[gleem]

SpaceX is chomping at the bit to launch Starship. SpaceX VP William Gerstemaier is to meet with Senators Wednesday to urge streamlining of the FAA review process and increasing their staff to me the increasing cadence of launches. https://www.washingtonpost.com/technology/2023/10/17/spacex-congress-licenses-faa-starship/

 

[mfb]

SpaceX battles regulatory process that could hold up Starship test flight for months

How can it take months to determine if dumping water into water harms the environment significantly? Stop all rainfall until we investigated its environmental impact (we expect an initial review in 2028)!

 

[mfb]

Static fire with ship 26
It doesn't have a heat shield so it's unclear if it will ever fly. If the second flight (with ship 25) reaches orbit then they might skip 26 and directly use ship 28 to work on reentry. Ship 27, which was similar to 26, has been scrapped already.

 

[mfb]

The Fish and Wildlife Service said they "do not expect to take the full amount of time", i.e. the 135 days they have at most (which would end in early March). That sounds like they plan to use most of it.
They also confirmed they were consulted to evaluate the water deluge system.

That's not even the most absurd part. The FWS only gets involved when FAA asks it, which only happens for launches. SpaceX has already used the deluge system, both as a standalone test and as operational system for a static fire test. They can use the deluge system as often as they want without FWS having anything to say about it - as long as they don't release the holddown clamps on the rocket. If they do that then suddenly FWS needs to check if the water affects a fish. If they keep delaying a launch then it's likely SpaceX will keep doing ground tests, which means they might use the deluge system more often than they would if they could launch.

 

[bob012345]

The Fish and Wildlife Service said they "do not expect to take the full amount of time", i.e. the 135 days they have at most (which would end in early March). That sounds like they plan to use most of it.
They also confirmed they were consulted to evaluate the water deluge system.

That's not even the most absurd part. The FWS only gets involved when FAA asks it, which only happens for launches. SpaceX has already used the deluge system, both as a standalone test and as operational system for a static fire test. They can use the deluge system as often as they want without FWS having anything to say about it - as long as they don't release the holddown clamps on the rocket. If they do that then suddenly FWS needs to check if the water affects a fish. If they keep delaying a launch then it's likely SpaceX will keep doing ground tests, which means they might use the deluge system more often than they would if they could launch.

FWS indeed. SpaceX should make a deal with Cuba where they might actually have more freedom to operate.

 

[Haborix]

FWS indeed. SpaceX should make a deal with Cuba where they might actually have more freedom to operate.

The U.S. government might really have something to say about THAT, hahaha.

 

[bob012345]

The U.S. government might really have something to say about THAT, hahaha.

Why? Would they threaten to nationalize SpaceX? What could they really do if SpaceX moved launch operations to another country?