totm nov 2023 SpaceX Discussion Thread

[SpaceFace545]

3 minutes ago, Spaceman.Spiff said:

So what do y’all think will happen with 15? Will they try again? If so, how long will inspection and possible refurb/replacement of the engines take?

Or will it hit the scrap heap?

I bet it will be taken apart or just stored outside in their rocket display. Its a rough prototype and I doubt it was built to fly more than once. I guess being able to stick the landing this time will allow a bit more leeway for SN16 but I still think SN16 will be roughly the same. If that can land and this landing wasn't just a fluke then spacex will probably move onto more durable and better prototypes.

[Spaceman.Spiff]

3 minutes ago, SpaceFace545 said:

I bet it will be taken apart or just stored outside in their rocket display. Its a rough prototype and I doubt it was built to fly more than once. I guess being able to stick the landing this time will allow a bit more leeway for SN16 but I still think SN16 will be roughly the same. If that can land and this landing wasn't just a fluke then spacex will probably move onto more durable and better prototypes.

Honestly I think they will try to launch it a second time as a proof of concept. If they can reuse it within a week, they will have sorta proved the whole schtick of SS

[RCgothic]

They have enough of a production queue that reuse isn't necessary at this stage. I expect SN16 to roll out for a repeat, given the FAA licence for the next mission is already issued and there were no obvious incidents with SN15 that would need investigating. Changing the mission parameters is probably not worth the hassle.

If SN16 goes well maybe they skip SN17 (which is also covered by the current licence) and jump straight to SN20, but that might mean a gap in testing whilst they sort BN3 and the integration tower and orbital launch pad out.

Reuse can come later.

Edited May 6, 2021 by RCgothic

[tater]

7 minutes ago, Serpens Solidus said:

SN15 would have missed the barge

Yeah, it was right on the edge, would have gone for a swim. Barge is certainly harder than a concrete pad.

They will do "hop" testing on land, and I think soft water landings until they sort out the flight regime so they can hit a barge (orbital testing).

4 minutes ago, SpaceFace545 said:

I bet it will be taken apart or just stored outside in their rocket display. Its a rough prototype and I doubt it was built to fly more than once. I guess being able to stick the landing this time will allow a bit more leeway for SN16 but I still think SN16 will be roughly the same. If that can land and this landing wasn't just a fluke then spacex will probably move onto more durable and better prototypes.

Likely, they have to do something with the prototypes that will never attempt orbit. On the plus side, data. They barely hit the pad yesterday, so they need to look at exactly why, and tweak the software. they've gotten rather good at hitting the target with F9, I have no doubt they will dial this one in for hops.

That makes the chance of doing well on the first orbital flights better, but that will require even more iteration I'm sure.

[StrandedonEarth]

I have to wonder if the edge-of-the-pad landing was a result of the wind. It blew the smoke/steam away from the landing site fairly quickly.

[Spaceman.Spiff]

3 minutes ago, tater said:

water landings until they sort out the flight regime so they can hit a barge (orbital testing).

Maybe RTLS?

[tater]

2 minutes ago, Spaceman.Spiff said:

Maybe RTLS?

I'm talking about orbital SS testing. It will be coming from the west (where people are relative to Boca Chica).

[RCgothic]

I think tater is probably right that re-entry descent and landing is better tested with soft Ocean landings before risking any barges or overflights of land.

I'm thinking they'll probably skip supersonic flight and RTLS and go straight to orbital testing. If we consider Elon's schedule of July for orbit there isn't much time to squeeze in supersonic testing beforehand, especially if SN16 and 17 face the same license restrictions as SN15.

 

 

 

[tater]

11 minutes ago, RCgothic said:

I'm thinking they'll probably skip supersonic flight and RTLS and go straight to orbital testing. If we consider Elon's schedule of July for orbit there isn't much time to squeeze in supersonic testing beforehand, especially if SN16 and 17 face the same license restrictions as SN15.

I think many forget that SS is the upper stage. It's not really designed to go at high speed unless it's on top of a booster. They climb slowly on these hops for a reason—the CM is too far back. Having the dv to hop to space, or even to SSTO doesn't mean that the vehicle could actually do that (as I would expect anyone who has played a lot of KSP would already know, flippy rockets being one of the first KSP object lessons in where to put the CM of a rocket).

[JoeSchmuckatelli]

22 minutes ago, RCgothic said:

I think tater is probably right that re-entry descent and landing is better tested with soft Ocean landings before risking any barges or overflights of land.

I'm thinking they'll probably skip supersonic flight and RTLS and go straight to orbital testing. If we consider Elon's schedule of July for orbit there isn't much time to squeeze in supersonic testing beforehand, especially if SN16 and 17 face the same license restrictions as SN15.

 

 

 

I'm almost as impressed with the crane as anything.  Not only do we have an enormous rocket that can fly, but we have a mobile crane that can lift the skyscraper sized thing. 

[RCgothic]

Even the mobile crane isn't big enough to stack Starship on top of Superheavy on the launch platform however. That's why the integration tower and its crane need finishing. The integration tower seems to be coming along nicely though.

[Silavite]

35 minutes ago, tater said:

I think many forget that SS is the upper stage. It's not really designed to go at high speed unless it's on top of a booster. They climb slowly on these hops for a reason—the CM is too far back. Having the dv to hop to space, or even to SSTO doesn't mean that the vehicle could actually do that (as I would expect anyone who has played a lot of KSP would already know, flippy rockets being one of the first KSP object lessons in where to put the CM of a rocket).

I'm not sure that stability is an issue. As long as the time constant for a perturbation away from the velocity vector isn't *too* quick, the flight controller in concert with TVC should be able to keep the vehicle pointed the right way. I would wager that most launch vehicles today are statically unstable.

[tater]

20 minutes ago, Silavite said:

I'm not sure that stability is an issue. As long as the time constant for a perturbation away from the velocity vector isn't *too* quick, the flight controller in concert with TVC should be able to keep the vehicle pointed the right way. I would wager that most launch vehicles today are statically unstable.

Starship CM is always to the rear (except after the flip). They could presumably ballast the cargo section to help as the CM moved even farther back as the tanks drain.

 

Cool shots of the liftoff and flip.

 

[Hannu2]

3 hours ago, RCgothic said:

I think tater is probably right that re-entry descent and landing is better tested with soft Ocean landings before risking any barges or overflights of land.

Why not? Barge is probably so cheap that if there is reasonable possibility of hitting it it is worth trying. Especially if passive barge can be used.

 

3 hours ago, RCgothic said:

I'm thinking they'll probably skip supersonic flight and RTLS and go straight to orbital testing. If we consider Elon's schedule of July for orbit there isn't much time to squeeze in supersonic testing beforehand, especially if SN16 and 17 face the same license restrictions as SN15.

 

I do not know is it reasonable idea but if they decide to skip fabricating new SN17 does that license allow SN15 to fly again as SN17?

[CatastrophicFailure]

This is promising...

 

[RealKerbal3x]

 

[Elthy]

17 minutes ago, CatastrophicFailure said:

This is promising...

 

Looks like the tile failed, not its attachment method. But i think there were other, small patches of tiles on SN15, one of which lost more tiles. No idea where i saw it, though.

 

Edit: Here, the lower patch:

 

Edited May 6, 2021 by Elthy

[RCgothic]

At least some of the lower tiles had been missing prior to flight.

[CatastrophicFailure]

27 minutes ago, RCgothic said:

At least some of the lower tiles had been missing prior to flight.

Indeed. Those lower tiles seemed to be more “test” tiles (they’re all test tiles, but...), with different sizes, etc, vs the more “production”-look of the fully-belted section. Someone with better math skills than me could extrapolate that one tile and give us a guesstimate of what the total loss would have been had the whole thing been covered... 

[magnemoe]

4 hours ago, tater said:

Yeah, it was right on the edge, would have gone for a swim. Barge is certainly harder than a concrete pad.

They will do "hop" testing on land, and I think soft water landings until they sort out the flight regime so they can hit a barge (orbital testing).

Likely, they have to do something with the prototypes that will never attempt orbit. On the plus side, data. They barely hit the pad yesterday, so they need to look at exactly why, and tweak the software. they've gotten rather good at hitting the target with F9, I have no doubt they will dial this one in for hops.

That makes the chance of doing well on the first orbital flights better, but that will require even more iteration I'm sure.

They could select an landing spot on the east coast, not for reuse but so they could get more data and they could reuse engines and expensive flight systems. 
Leave the first who land intact as an memorial like an museum ship. 
Barge also probably work but is harder as its some inaccuracy in the flip who the engine has to compensate for. 

[RCgothic]

SpaceX statement on yesterday's flight. Interesting detail on transition to header tanks *before* the kick flip. I think I've seen it mentioned before, but it's been so subtle on viewings of previous flights. (Not that we saw anything this flight)

"Starship Superheavy (collectively referred to as starship)" is such an awkward terminology. I am personally never going to refer to it that way. As far as I'm concerned:

Starship is the upper Stage.

Superheavy is the booster.

Starship Superheavy is the full rocket.

"The Starship System" is the full ecosystem of starship variants and booster.

 

Clearly they missed an opportunity to refer to the combined rocket as SuperStar.

Edited May 6, 2021 by RCgothic

[tater]

47 minutes ago, RCgothic said:

"Starship Superheavy (collectively referred to as starship)" is such an awkward terminology. I am personally never going to refer to it that way. As far as I'm concerned:

They could call it the Starship Launch System.

The text from the link above:

Quote

On Wednesday, May 5, Starship serial number 15 (SN15) successfully completed SpaceX’s fifth high-altitude flight test of a Starship prototype from Starbase in Texas.

Similar to previous high-altitude flight tests of Starship, SN15 was powered through ascent by three Raptor engines, each shutting down in sequence prior to the vehicle reaching apogee – approximately 10 km in altitude. SN15 performed a propellant transition to the internal header tanks, which hold landing propellant, before reorienting itself for reentry and a controlled aerodynamic descent.

The Starship prototype descended under active aerodynamic control, accomplished by independent movement of two forward and two aft flaps on the vehicle. All four flaps were actuated by an onboard flight computer to control Starship’s attitude during flight and enabled precise landing at the intended location. SN15’s Raptor engines reignited as the vehicle performed the landing flip maneuver immediately before touching down for a nominal landing on the pad.

These test flights of Starship are all about improving our understanding and development of a fully reusable transportation system designed to carry both crew and cargo on long-duration interplanetary flights, and help humanity return to the Moon, and travel to Mars and beyond.

Congratulations to the entire SpaceX team on SN15’s successful flight and landing!

 

 

[Xd the great]

3 hours ago, CatastrophicFailure said:

Indeed. Those lower tiles seemed to be more “test” tiles (they’re all test tiles, but...), with different sizes, etc, vs the more “production”-look of the fully-belted section. Someone with better math skills than me could extrapolate that one tile and give us a guesstimate of what the total loss would have been had the whole thing been covered... 

With 10,000 tiles (on orbital starship), some are almost bound to get lose. Hard part is whether lost tiles would cause another Columbia disaster.

[SunlitZelkova]

1 hour ago, RCgothic said:

SpaceX statement on yesterday's flight. Interesting detail on transition to header tanks *before* the kick flip. I think I've seen it mentioned before, but it's been so subtle on viewings of previous flights. (Not that we saw anything this flight)

"Starship Superheavy (collectively referred to as starship)" is such an awkward terminology. I am personally never going to refer to it that way. As far as I'm concerned:

Starship is the upper Stage.

Superheavy is the booster.

Starship Superheavy is the full rocket.

"The Starship System" is the full ecosystem of starship variants and booster.

 

Clearly they missed an opportunity to refer to the combined rocket as SuperStar.

I think it is intended to be similar to N1-L3 or Energia-Buran, but without the dash and reversed. So if Orion were to launch on Superheavy it would be Orion Superheavy.

Out of curiosity, are there any other rockets that use an adjective as a name? Sometimes when I see people discussing Superheavy it makes me think "Superheavy what?".

Is Superheavy a relative in name only to Falcon? So technically it is Falcon Superheavy, which makes more sense as there is Falcon Heavy.

[tater]

Technically the booster is Super Heavy.