SpaceX Starship - IFT-5 - Starbase TX - Pre-Launch Preparations Thread

[JB47394]

OK, maybe we can still make this bet real! Elon just posted:

That suggests that they're going to risk their only launch facility. I could imagine them bringing the booster back to the launch site (to establish accuracy), but then dumping it in the Gulf and recovering it with a ship. Tow it to a port and lift the 200 ton behemoth out of the water. Even if they attempt a catch, they need some kind of contingency plan for a failure.

And surely the new launch facility won't be ready for another year. It took nearly four years of development to get where they are today.

 

[Cosmacelf]

That suggests that they're going to risk their only launch facility. I could imagine them bringing the booster back to the launch site (to establish accuracy), but then dumping it in the Gulf and recovering it with a ship. Tow it to a port and lift the 200 ton behemoth out of the water. Even if they attempt a catch, they need some kind of contingency plan for a failure.

And surely the new launch facility won't be ready for another year. It took nearly four years of development to get where they are today.

They are well on their way to finishing a second launch site at Boca Chica. It’ll be a landing tower for now without the support equipment for launch initially.

 

[JB47394]

They are well on their way to finishing a second launch site at Boca Chica. It’ll be a landing tower for now without the support equipment for launch initially.

If they only go for the tower, yeah, I can see that happening in a few months. All the bits and pieces for the tower exist, and they're setting up for the foundation pour now. I remain curious to know what they'll do with the booster if the catch doesn't happen. I wonder what the FAA and the EPA will think of SpaceX dumping the booster somewhere nearby.

Edit: And right on cue, Marcus House's latest video shows that SpaceX has moved the remaining big tower hardware from the Cape onto a barge. This included two tower sections, the brace for the ship quick disconnect, and the tower arms. The ship quick disconnect itself and the launch mount table are not part of this trip.

 

[DarthPierce]

I hope South Padre is prepared for some big sonic booms from something that size coming back in. I am still not sure real booster recovery will be a thing until the offshore rigs are ready.

 

[Grendal]

I'm not sure that a landing failure back at the launch site would be destructive in a significant way. I'd expect it to be along the lines of the damage from the IFT-1 launch. The booster will not be going too fast and it will be almost empty of fuel. If you compare that to the incredible energy of the initial launch then my intuition says that this is somewhat less damaging except for the potential large pieces being dropped on less shielded equipment.

Much like F9 landings on ASDS's and landing zones, there will be a diversion point where the booster will go for an off shore landing if they think the potential landing is "off nominal."

 

[JB47394]

I hope South Padre is prepared for some big sonic booms from something that size coming back in. I am still not sure real booster recovery will be a thing until the offshore rigs are ready.

There's a PDF for that.

https://www.faa.gov/sites/faa.gov/files/space/stakeholder_engagement/spacex_starship/Appendix_B_Noise_Assessment.pdf

Here's the signature for an orbital launch. The southernmost tip of South Padre Island gets hit with 100 dB.

And the signature for an orbital landing. The southernmost tip of South Padre Island gets hit with 120 dB.

I wonder if this will be the ultimate result.

 

[TunaBug]

There's a PDF for that.

https://www.faa.gov/sites/faa.gov/files/space/stakeholder_engagement/spacex_starship/Appendix_B_Noise_Assessment.pdf

Here's the signature for an orbital launch. The southernmost tip of South Padre Island gets hit with 100 dB.

View attachment 1054462

And the signature for an orbital landing. The southernmost tip of South Padre Island gets hit with 120 dB.

View attachment 1054461

I wonder if this will be the ultimate result.

Thanks for the link to the PDF! However, after looking at the plots that you included, which show that landing a a LOT louder than take-off, I decided to flip through the PDF. You omitted the keys/labels of the graphs and ended up comparing apples to oranges. Easy to do; there are a lot of those plots in the PDF, each taking a page, and lots of paging flipping between them makes it easy to get lost. Your first image (take-off) is A-Weighted. The units are dBA, not dB. The second is just plain old dB.

Looking at the PDF, it appears that when using identical units the take-off and landing plots are quite close. Even that surprises me, I was expecting landing to be much less noisy. Which makes me think that I'm not understanding something.

The PDF is also from 2020, so the numbers are probably bit off now that they have actual engines and launches to measure.

 

[TunaBug]

What is needed from the FAA for IFT-5? Do they need a separate license for each launch, or is that covered by prior licenses?

For IFT-2...4 it seemed like the long pole for FAA approvals was the mishap investigation, but I'm assuming/hoping that this can be avoided for IFT-5. Here's something from an Ars article on 6/4 (prior to IFT-4, and about the FAA approval for IFT-4), originally quoted by @scaesare , which I'm re-quoting here so that we don't go running around different threads to find it...

Based on language in the code of federal regulations, the FAA has the option to approve these exceptions. The FAA accepted three possible outcomes for the upcoming Starship test flight that would not trigger what would likely be a months-long mishap investigation.

These exceptions include the failure of Starship's heat shield during reentry if the ship's flap system is unable to provide sufficient control under high dynamic pressure, and the failure of the Raptor engine system during the landing burn. If one of these scenarios occurs, the FAA will not require a mishap investigation, provided there was no serious injury or fatality to anyone on the ground, no damage to unrelated property, and no debris outside designated hazard areas.

 

[DarthPierce]

Takeoff is dominated by the rumble from the engines. Landing is dominated by the sonic boom of a 10m cylinder coming in at 4000km/hr.
So long rumble vs a few super sharp cracks.

 

[Ben W]

Takeoff is dominated by the rumble from the engines. Landing is dominated by the sonic boom of a 10m cylinder coming in at 4000km/hr.
So long rumble vs a few super sharp cracks.

They split out the sonic boom analysis separately at the end of the PDF; it’s not clear whether it’s part of the earlier figures.

I have to believe that relative velocity plays a significant role; 13 Raptors heading toward you at Mach 0.5 is plausibly just as loud as 33 Raptors heading away from you at Mach 0.5.

 

[JB47394]

What is needed from the FAA for IFT-5? Do they need a separate license for each launch, or is that covered by prior licenses?

The licenses say what they cover. For example, the Falcon 9 license covers an unlimited number of launches over a specified time period, while in contrast the Starship licenses have been for single launches. Each Starship launch is different, so the FAA wants to review each one. Once SpaceX gets into a rhythm of launching the same design of Starship on the same missions, they'll get a multiple launch license.

For IFT-5, SpaceX will need to have the launch license updated to cover that launch. The FAA and SpaceX will negotiate the vehicle capabilities and the parameters of the mission, then the license will be issued. If SpaceX says that they want to repeat the IFT-5 mission multiple times, with the same vehicle design and the same mission parameters, they might even get a license for multiple launches.

 

[TunaBug]

Takeoff is dominated by the rumble from the engines. Landing is dominated by the sonic boom of a 10m cylinder coming in at 4000km/hr.
So long rumble vs a few super sharp cracks.

I'm used to thinking of sonic booms in terms of a jet flying overhead (a sharp crack as it passes), and not a 10m cylinder coming downward and toward me. What does a sonic boom sound like when the vehicle is coming at you instead of flying past? I'm assuming it's not just a single sharp noise?

 

[JB47394]

What does a sonic boom sound like when the vehicle is coming at you instead of flying past?

It's a sharp crack. Falcon 9 boosters produce multiple such cracks when returning to the landing site. The farther you are, of course, the less distinct it is.

 

[ecarfan]

Things that caught my attention that are relevant to this thread:

“We had 16 video feeds or thereabouts from Starlink some of which were external most of which were internal”. So what SpaceX showed to the public during the flight was just a small fraction of what they were recording and perhaps for IFT-5 we will get to see more external camera views?

IFT-5 is planned to have continuous Starlink coverage..

On IFT-4 the booster came to a “precise location” and “came to essentially zero velocity on the ocean” so “should probably try to catch it with the tower arms on the next flight”.

 

[ecarfan]

They are well on their way to finishing a second launch site at Boca Chica. It’ll be a landing tower for now without the support equipment for launch initially.

Hmm…I had not thought of that. Interesting idea. However, is your statement based on the observation that OLM foundation work has not started yet (right?) or do you have a SpaceX source that is saying that?

In any case, it’s hard for me to imagine SpaceX finishing tower #2 before the end of this year.

I'm not sure that a landing failure back at the launch site would be destructive in a significant way.

If the first booster catch attempt fails it seems to me that it is possible that the launch site could be significantly damaged. I assume that for the catch the chopsticks will be positioned as far to the side of the OLM as possible but that is still less than 50m away(?). And if the chopsticks are severely damaged then they won’t be able to stack the vehicles for IFT-6 until they are repaired/replaced.

Going for a booster catch on IFT-5 is a real risk given that OLM #2 won’t be ready until sometime later in 2025 (my guess!). Also, the hot staging ring design used for that flight will still be the prototype design (as far as I know) so the booster landing technique won’t match with the V2 version. Of course booster/ship design will continuously evolve for years to come so I guess that doesn’t really matter. Elon seems intent on achieving booster recovery as early as possible, but given how many flights it is going to take to successfully land the ship so perhaps one or two more booster water landings might be a better course?

 

[Electroman]

It's a sharp crack. Falcon 9 boosters produce multiple such cracks when returning to the landing site. The farther you are, of course, the less distinct it is.

I am wondering from where did this guy take that landing video of the two FH boosters?

Seems like a perfect spot to watch both the launch and landing. I would pay top dollar to go there and watch the show next time they have a FH launch.

 

[JB47394]

I am wondering from where did this guy take that landing video of the two FH boosters?

It looks like he's in the tower at Pad 37B, so you'd have to know somebody to get up there. He was positioned about 10km south of the launch site (39A) and 5.5km north of the landing site. He probably works for one of the companies or agencies involved with the site. ULA, Air Force, etc.

 

[Grendal]

If the first booster catch attempt fails it seems to me that it is possible that the launch site could be significantly damaged. I assume that for the catch the chopsticks will be positioned as far to the side of the OLM as possible but that is still less than 50m away(?). And if the chopsticks are severely damaged then they won’t be able to stack the vehicles for IFT-6 until they are repaired/replaced.

Going for a booster catch on IFT-5 is a real risk given that OLM #2 won’t be ready until sometime later in 2025 (my guess!). Also, the hot staging ring design used for that flight will still be the prototype design (as far as I know) so the booster landing technique won’t match with the V2 version. Of course booster/ship design will continuously evolve for years to come so I guess that doesn’t really matter. Elon seems intent on achieving booster recovery as early as possible, but given how many flights it is going to take to successfully land the ship so perhaps one or two more booster water landings might be a better course?

Keep in mind that SpaceX crashed three or four boosters into the ASDS. Those were extremely explosive and none of them damaged the ASDS to any greater extent. It's a nearly empty booster with very little momentum left.

 

[JB47394]

Keep in mind that SpaceX crashed three or four boosters into the ASDS. Those were extremely explosive and none of them damaged the ASDS to any greater extent. It's a nearly empty booster with very little momentum left.

The comparison is tough. A Falcon 9 booster masses 26 tons of aluminum lithium, versus the Starship booster's 200 tons of stainless steel. The Falcon 9 booster is landing on a flat steel plate supported by sea water across its underside, while the tubular steel catch arms of the Starship tower are supported by hinge points. Then there's the question of what a pair of large tanks pressurized with methane and oxygen would do if there was a crash. They're going to be pressurized regardless of how much propellant is onboard, and apparently the mass of the pressurized gas is measured in tons.

I'd say that the best way to approach a Starship booster landing is off to the side of the tower. Trying for a direct flight to the arms seems foolish to me.

 

[Mike1080i]

It looks like he's in the tower at Pad 37B, so you'd have to know somebody to get up there. He was positioned about 10km south of the launch site (39A) and 5.5km north of the landing site. He probably works for one of the companies or agencies involved with the site. ULA, Air Force, etc.

You are correct. LC-34 (site of Apollo 1 and 7) is visible in the shot and is the next pad south of 37.