SpaceX Starship : First Flight : Starbase, TX : 20 April 2023 - DISCUSSION

[DanClemmensen]

Folks,

I apologize if I'm asking a question that's already been answered, but reading the article posted on NSF I'm a bit confused.  Are they not going to attempt recovery of the booster or starship?  I was under the impression that they would at least attempt to recover the upper stage.  Any clarification appreciated!

I thought the idea was both stages soft land at sea.  Whether they get towed back in I've never seen mentioned one way or another.  I can't imagine them just leaving them floating around at sea though.

There was an extensive discussion about this about 18 months ago. We assume they intend to do the same maneuver they will need as part of a chopsticks landing, but over empty ocean, reaching a zero-velocity vertical orientation just above the sea surface. The question: what happens next? if they simply cut off the engines, the booster (in the gulf of Mexico) and  an hour later the Starship (off Hawaii) will fall into the water. These are big and relatively fragile structures. They will probably crumple, take on water, and sink: think of a 22-story building and a 16-story building made of steel so thin that it can buckle if not pressurized. There are several possible tricks that might mitigate this, but we have no reason to believe SpaceX intends to do any of them.

[LinuxForAll]

By happy coincidence, I am going to be in Hawaii on starting April 17th visiting the islands Oahu and Kauai. If I go to the north shore when the water landing is attempted, is there a chance that I may be able to catch a glimpse of the water landing off in the distance, or it is still going to be too far away?

[InterestedEngineer]

Folks,

I apologize if I'm asking a question that's already been answered, but reading the article posted on NSF I'm a bit confused.  Are they not going to attempt recovery of the booster or starship?  I was under the impression that they would at least attempt to recover the upper stage.  Any clarification appreciated!

I thought the idea was both stages soft land at sea.  Whether they get towed back in I've never seen mentioned one way or another.  I can't imagine them just leaving them floating around at sea though.

There was an extensive discussion about this about 18 months ago. We assume they intend to do the same maneuver they will need as part of a chopsticks landing, but over empty ocean, reaching a zero-velocity vertical orientation just above the sea surface. The question: what happens next? if they simply cut off the engines, the booster (in the gulf of Mexico) and  an hour later the Starship (off Hawaii) will fall into the water. These are big and relatively fragile structures. They will probably crumple, take on water, and sink: think of a 22-story building and a 16-story building made of steel so thin that it can buckle if not pressurized. There are several possible tricks that might mitigate this, but we have no reason to believe SpaceX intends to do any of them.

Been hashed over so many times, and you didn't present the counter hypothesis, that

1.  Falcon-9 has had successful landings on the ocean and didn't break up
2.  The math shows that there's a good possibility of intact survival

Why don't you link to the thread instead of just presenting one side of it and causing the argument all over again

[Malisk]

By happy coincidence, I am going to be in Hawaii on starting April 17th visiting the islands Oahu and Kauai. If I go to the north shore when the water landing is attempted, is there a chance that I may be able to catch a glimpse of the water landing off in the distance, or it is still going to be too far away?

according to this, the landing will be 200km+ North of Honolulu but the inbound path is ~100km-200km northwest of Kauai. Using a site like this you can see that at best you will be able to see the ship while it is 3km+ above sea level. Just the fact that it will be 200km a way though means you likely could not see it with the naked eye at all.

[Robotbeat]

Folks,

I apologize if I'm asking a question that's already been answered, but reading the article posted on NSF I'm a bit confused.  Are they not going to attempt recovery of the booster or starship?  I was under the impression that they would at least attempt to recover the upper stage.  Any clarification appreciated!

I thought the idea was both stages soft land at sea.  Whether they get towed back in I've never seen mentioned one way or another.  I can't imagine them just leaving them floating around at sea though.

There was an extensive discussion about this about 18 months ago. We assume they intend to do the same maneuver they will need as part of a chopsticks landing, but over empty ocean, reaching a zero-velocity vertical orientation just above the sea surface. The question: what happens next? if they simply cut off the engines, the booster (in the gulf of Mexico) and  an hour later the Starship (off Hawaii) will fall into the water. These are big and relatively fragile structures. They will probably crumple, take on water, and sink: think of a 22-story building and a 16-story building made of steel so thin that it can buckle if not pressurized. There are several possible tricks that might mitigate this, but we have no reason to believe SpaceX intends to do any of them.

Just like with Falcon 9, will *probably* crumple, but they *might not*. Therefore they’ll need a plant to either tow them to shore or to sink them. No one has made a strong enough argument to me that sinking is assured, ie that they won’t need the ability to tow or sink them. Marine safety considerations means we can’t count on them for sure crumpling.

[Herb Schaltegger]

I think there’s a higher likelihood of landing RUD than there is of a floating/bobbing Starship simply based on the propellants involved. Unlike that infamous Floating Falcon, Starship is going to have at least some residual methane and LOX unless they intentionally void the tanks and purge them with N2 or something well before impact. So assuming there are any residual propellants, unless there is an absolutely perfectly smooth touchdown and sloooow sinking to bob-depth, there’s a real risk of a conflagration or explosion.

[KSHavre]

Folks,

I apologize if I'm asking a question that's already been answered, but reading the article posted on NSF I'm a bit confused.  Are they not going to attempt recovery of the booster or starship?  I was under the impression that they would at least attempt to recover the upper stage.  Any clarification appreciated!

I thought the idea was both stages soft land at sea.  Whether they get towed back in I've never seen mentioned one way or another.  I can't imagine them just leaving them floating around at sea though.

There was an extensive discussion about this about 18 months ago. We assume they intend to do the same maneuver they will need as part of a chopsticks landing, but over empty ocean, reaching a zero-velocity vertical orientation just above the sea surface. The question: what happens next? if they simply cut off the engines, the booster (in the gulf of Mexico) and  an hour later the Starship (off Hawaii) will fall into the water. These are big and relatively fragile structures. They will probably crumple, take on water, and sink: think of a 22-story building and a 16-story building made of steel so thin that it can buckle if not pressurized. There are several possible tricks that might mitigate this, but we have no reason to believe SpaceX intends to do any of them.

Just like with Falcon 9, will *probably* crumple, but they *might not*. Therefore they’ll need a plant to either tow them to shore or to sink them. No one has made a strong enough argument to me that sinking is assured, ie that they won’t need the ability to tow or sink them. Marine safety considerations means we can’t count on them for sure crumpling.

Would they be able to use the explosives for safeing a wayward rocket, to make big holes in the tanks?

[edzieba]

That would require the ability to remotely arm the FTS after disarming it, which would be safety hazard.

Like with Falcon 9, if the vehicle survives tipover intact (more probable than not with Falcon 9 ocean landings that did not cut engines at altitude, unknown for Starship or Super Heavy) it will not take long for wave action to break up the stage once it has depressurised.

[Slothman]

You all assume that the heatshield holds.

[John Santos]

You all assume that the heatshield holds.

If the heat shield does not hold, then the issue of floating debris (a hazard to navigation) is moot.  No one is assuming that the heat shield holds, but no one is assuming it fails, either.

[DanClemmensen]

You all assume that the heatshield holds.

There are two "landings". The booster landing does not depend on a heat shield. SS needs its TPS to work (and also lots of other stuff) to survive re-entry. A landing failure of SS would still be a spectacularly successful test flight.

[TheRadicalModerate]

You all assume that the heatshield holds.

If the heat shield does not hold, then the issue of floating debris (a hazard to navigation) is moot.  No one is assuming that the heat shield holds, but no one is assuming it fails, either.

Tiles + insulating blanket will likely float.  Tiles + blanket + skin might float in some cases, if the pieces of debris were small.  Tiles + blanket + skin + stringer will probably sink.

[TheRadicalModerate]

You all assume that the heatshield holds.

There are two "landings". The booster landing does not depend on a heat shield. SS needs its TPS to work (and also lots of other stuff) to survive re-entry. A landing failure of SS would still be a spectacularly successful test flight.

A nit to pick:  The booster needs TPS as well.  It's just not as extensive as the Starship, and it's considerably less exotic.

[envy887]

Folks,

I apologize if I'm asking a question that's already been answered, but reading the article posted on NSF I'm a bit confused.  Are they not going to attempt recovery of the booster or starship?  I was under the impression that they would at least attempt to recover the upper stage.  Any clarification appreciated!

I thought the idea was both stages soft land at sea.  Whether they get towed back in I've never seen mentioned one way or another.  I can't imagine them just leaving them floating around at sea though.

There was an extensive discussion about this about 18 months ago. We assume they intend to do the same maneuver they will need as part of a chopsticks landing, but over empty ocean, reaching a zero-velocity vertical orientation just above the sea surface. The question: what happens next? if they simply cut off the engines, the booster (in the gulf of Mexico) and  an hour later the Starship (off Hawaii) will fall into the water. These are big and relatively fragile structures. They will probably crumple, take on water, and sink: think of a 22-story building and a 16-story building made of steel so thin that it can buckle if not pressurized. There are several possible tricks that might mitigate this, but we have no reason to believe SpaceX intends to do any of them.

Just like with Falcon 9, will *probably* crumple, but they *might not*. Therefore they’ll need a plant to either tow them to shore or to sink them. No one has made a strong enough argument to me that sinking is assured, ie that they won’t need the ability to tow or sink them. Marine safety considerations means we can’t count on them for sure crumpling.

Superheavy going for a chopstick landing will come to a stop and cut it's engines while still some 50 meters in the air. Without the chopsticks to land in, it will fall that distance to the surface, and I don't see any way it can survive that, water or no water.

I could see it maybe surviving a zero-zero landing. But why would SpaceX do a zero-zero landing when that's not the intended mode of operation?

[TheRadicalModerate]

Superheavy going for a chopstick landing will come to a stop and cut it's engines while still some 50 meters in the air. Without the chopsticks to land in, it will fall that distance to the surface, and I don't see any way it can survive that, water or no water.

I could see it maybe surviving a zero-zero landing. But why would SpaceX do a zero-zero landing when that's not the intended mode of operation?

I'd feel confident that if you twiddled the guidance parameter that specified 0m/s at 50m to be 0m/s at 2m, you'd have proven your landing regime worked, and it was time to try the chopsticks, set at 50/0, your next flight.

I keep wondering if you really tune the system to be at 0m/s and hovering just as the hard points reach the height of the chopstick catch rails.  I suspect that it'll be more reliable to have something analogous to a hoverslam, with things programmed to be at maybe -1m/s when the hard points should be scraping past the catch rails.  Seems a lot more likely to have reliable contact--which stays reliable as the engines shut down.  If you're hovering, the possibility of an upward bounce during shutdown could ruin your day.

[Robotbeat]

Folks,

I apologize if I'm asking a question that's already been answered, but reading the article posted on NSF I'm a bit confused.  Are they not going to attempt recovery of the booster or starship?  I was under the impression that they would at least attempt to recover the upper stage.  Any clarification appreciated!

I thought the idea was both stages soft land at sea.  Whether they get towed back in I've never seen mentioned one way or another.  I can't imagine them just leaving them floating around at sea though.

There was an extensive discussion about this about 18 months ago. We assume they intend to do the same maneuver they will need as part of a chopsticks landing, but over empty ocean, reaching a zero-velocity vertical orientation just above the sea surface. The question: what happens next? if they simply cut off the engines, the booster (in the gulf of Mexico) and  an hour later the Starship (off Hawaii) will fall into the water. These are big and relatively fragile structures. They will probably crumple, take on water, and sink: think of a 22-story building and a 16-story building made of steel so thin that it can buckle if not pressurized. There are several possible tricks that might mitigate this, but we have no reason to believe SpaceX intends to do any of them.

Just like with Falcon 9, will *probably* crumple, but they *might not*. Therefore they’ll need a plant to either tow them to shore or to sink them. No one has made a strong enough argument to me that sinking is assured, ie that they won’t need the ability to tow or sink them. Marine safety considerations means we can’t count on them for sure crumpling.

Superheavy going for a chopstick landing will come to a stop and cut it's engines while still some 50 meters in the air. Without the chopsticks to land in, it will fall that distance to the surface, and I don't see any way it can survive that, water or no water.

I could see it maybe surviving a zero-zero landing. But why would SpaceX do a zero-zero landing when that's not the intended mode of operation?

If they want to recover it for inspection.

[envy887]

If they want to recover it for inspection.

That would be an immensely challenging task. Is there any evidence that they are planning to attempt it?

[Robotbeat]

If they want to recover it for inspection.

That would be an immensely challenging task....

Not really. Was done for SRBs. For Shuttle and Ariane 5. Doable if it does survive somehow. Don't know if they'll want to.

[envy887]

If they want to recover it for inspection.

That would be an immensely challenging task....

Not really. Was done for SRBs. For Shuttle and Ariane 5. Doable if it does survive somehow. Don't know if they'll want to.

Despite the fact that the SRBs were much smaller and much sturdier, recovery was still very challenging, requiring dedicated support hardware, ships, crews, and training. Have we seen any of those?

[Vahe231991]

Is Elon Musk open to having the first orbital flight of the Starship make two or three orbits, given that the purpose of the first Starship launch will be to test the in-space behavior of the second stage of the Starship? This possibility shouldn't be ruled out because the first and only orbital flight of the Buran made two orbits before the Buran returned to Earth.