SpaceX (Vol. 2)
Discussion
GTO-3R said:
CraigyMc said:
GTO-3R said:
Sounds like flight 4 could be coming round pretty soon 
If Musk's anything to go by, 4,5,6,7,8,9 and 10... April or May for IFT4 seems pretty fast though, given the gap from IFT2 to IFT3.
CraigyMc said:
GTO-3R said:
Sounds like flight 4 could be coming round pretty soon
If Musk's anything to go by, 4,5,6,7,8,9 and 10... April or May for IFT4 seems pretty fast though, given the gap from IFT2 to IFT3.
IFT2 had 17 corrective actions
IFT3 might have less.
The cadence of launches should get closer together as the number (and seriousness) of corrective actions between each test gets smaller. IMHO I don't think that a May launch is overly ambitious
I'm a little surprised - and this is not a criticism - that on first glance the major issues they had on the last flight (loss of control, aero instability, ?frozen thrusters) are things that they had already solved on Falcon, or are things that you would imagine could have been simulated on their super duper turbo CAD / FEA software.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
FAA said:
Commercial Space / Boca Chica, Texas
A mishap occurred during the SpaceX Starship OFT-3 mission that launched from Boca Chica, Texas, on March 14. The mishap involved both the Super Heavy booster and the Starship vehicle.
No public injuries or public property damage have been reported. The FAA is overseeing the SpaceX-led mishap investigation to ensure the company complies with its FAA-approved mishap investigation plan and other regulatory requirements.
Background
?
A mishap investigation is designed to further enhance public safety, determine the root cause of the event, and identify corrective actions to avoid it from happening again.
?
The FAA will be involved in every step of the mishap investigation process and must approve SpaceX’s final report, including any corrective actions.
A return to flight is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety. In addition, SpaceX may need to modify its license to incorporate any corrective actions and meet all other licensing requirements.
https://www.faa.gov/newsroom/statementsA mishap occurred during the SpaceX Starship OFT-3 mission that launched from Boca Chica, Texas, on March 14. The mishap involved both the Super Heavy booster and the Starship vehicle.
No public injuries or public property damage have been reported. The FAA is overseeing the SpaceX-led mishap investigation to ensure the company complies with its FAA-approved mishap investigation plan and other regulatory requirements.
Background
?
A mishap investigation is designed to further enhance public safety, determine the root cause of the event, and identify corrective actions to avoid it from happening again.
?
The FAA will be involved in every step of the mishap investigation process and must approve SpaceX’s final report, including any corrective actions.
A return to flight is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety. In addition, SpaceX may need to modify its license to incorporate any corrective actions and meet all other licensing requirements.
I'd imagine SpaceX want to prevent loss of Starship control on re-entry, payload door malfunctions, booster Mach 1 entry into water and have no loss of material from the ship during launch as key improvements on the next flight.
I'm predicting end of May 2024 at the earliest.
Edited by LivLL on Friday 22 March 13:49
Hammersia said:
I'm a little surprised - and this is not a criticism - that on first glance the major issues they had on the last flight (loss of control, aero instability, ?frozen thrusters) are things that they had already solved on Falcon, or are things that you would imagine could have been simulated on their super duper turbo CAD / FEA software.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
- Falcon doesn't use methane as fuel Starship does -- kerosene isn't as hard to manage as liquid methane.
- Falcon upper stage uses bottled nitrogen cold gas thrusters for control, Starship uses autogenous thrusters (gas from the primary tanks)
- Falcon upper stage has no fuel transfer capability, Starship does (demo'ed on IFT3). This changes mass distribution/balance.
- Falcon upper stage isn't reusable, so it has no re-entry capability, Starship is built with tiles to do this.
Starship development is going unbelievably well, especially given the timelines and costs.
I read somewhere the other day that Raptor 3 is currently about $250K per unit, fully reusable.
33 of them on the bottom of the superheavy booster is therefore in the region of $8.25m in motors.
A single RS25 for SLS is in the region of $100m -- SLS needs 4 of these per launch, so $400m in motors, not-reusable -- and this for a motor whose development was paid for decades ago.
It's not just technology they are getting right at SpaceX. Production manufacturing at this scale without enormous costs is really impressive.
Hammersia said:
I'm a little surprised - and this is not a criticism - that on first glance the major issues they had on the last flight (loss of control, aero instability, ?frozen thrusters) are things that they had already solved on Falcon, or are things that you would imagine could have been simulated on their super duper turbo CAD / FEA software.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
I wouldn't think they plan failures for the publicity. For anyone that cares it's already a spectacle, and a rocket landing is way better PR than one burning up. Exploding rockets arn't going to win customers.Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
They do turn them into good PR though, but that's just a byproduct.
CraigyMc said:
Hammersia said:
I'm a little surprised - and this is not a criticism - that on first glance the major issues they had on the last flight (loss of control, aero instability, ?frozen thrusters) are things that they had already solved on Falcon, or are things that you would imagine could have been simulated on their super duper turbo CAD / FEA software.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
- Falcon doesn't use methane as fuel Starship does -- kerosene isn't as hard to manage as liquid methane.
- Falcon upper stage uses bottled nitrogen cold gas thrusters for control, Starship uses autogenous thrusters (gas from the primary tanks)
- Falcon upper stage has no fuel transfer capability, Starship does (demo'ed on IFT3). This changes mass distribution/balance.
- Falcon upper stage isn't reusable, so it has no re-entry capability, Starship is built with tiles to do this.
Starship development is going unbelievably well, especially given the timelines and costs.
I read somewhere the other day that Raptor 3 is currently about $250K per unit, fully reusable.
33 of them on the bottom of the superheavy booster is therefore in the region of $8.25m in motors.
A single RS25 for SLS is in the region of $100m -- SLS needs 4 of these per launch, so $400m in motors, not-reusable -- and this for a motor whose development was paid for decades ago.
It's not just technology they are getting right at SpaceX. Production manufacturing at this scale without enormous costs is really impressive.
Hammersia said:
CraigyMc said:
Hammersia said:
I'm a little surprised - and this is not a criticism - that on first glance the major issues they had on the last flight (loss of control, aero instability, ?frozen thrusters) are things that they had already solved on Falcon, or are things that you would imagine could have been simulated on their super duper turbo CAD / FEA software.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
- Falcon doesn't use methane as fuel Starship does -- kerosene isn't as hard to manage as liquid methane.
- Falcon upper stage uses bottled nitrogen cold gas thrusters for control, Starship uses autogenous thrusters (gas from the primary tanks)
- Falcon upper stage has no fuel transfer capability, Starship does (demo'ed on IFT3). This changes mass distribution/balance.
- Falcon upper stage isn't reusable, so it has no re-entry capability, Starship is built with tiles to do this.
Starship development is going unbelievably well, especially given the timelines and costs.
I read somewhere the other day that Raptor 3 is currently about $250K per unit, fully reusable.
33 of them on the bottom of the superheavy booster is therefore in the region of $8.25m in motors.
A single RS25 for SLS is in the region of $100m -- SLS needs 4 of these per launch, so $400m in motors, not-reusable -- and this for a motor whose development was paid for decades ago.
It's not just technology they are getting right at SpaceX. Production manufacturing at this scale without enormous costs is really impressive.
Of course, then you go operational after those years - and still find a whole host of s
t that goes wrong that comes out of nowhere, and some of those things you've added expensive/capability reducing preventative measures against actually in the real world aren't necessary - but you don't know that. 98elise said:
I wouldn't think they plan failures for the publicity. For anyone that cares it's already a spectacle, and a rocket landing is way better PR than one burning up. Exploding rockets arn't going to win customers.
They do turn them into good PR though, but that's just a byproduct.
Blooper reel They do turn them into good PR though, but that's just a byproduct.
They basically have an expendable rocket already. They cut the burn short to deliberately not orbit the ship. The hard part is of course the reuse.
Elon said they wanted to launch 6 of them this year. I think that's a little ambitious, but I wouldn't be surprised if they did 4 more in the remaining 9 months. I believe they have 4 unused Starship boosters and ships waiting to go. So, short of major redesigns, they can all be prepared in a matter of months to launch. The factory is being fitted out to produce more, but they're basically idling right now. They make one Raptor engine per day on average, but demand doesn't dictate a higher rate yet.
I'm sure they have access to state of the art computer modelling, but there's no substitute for practical experience. They will have got masses of data from the last launch, which will all inform the design and planning of future flights.
The booster didn't plough directly into the sea by the way. At least not in one piece - It blew up before that. It wasn't the flight termination system that did it either, as you can hear the "FTS is safed" call out on the commentary. SpaceX said it blew up about 462 meters above the water. It looks like it was unstable & the flight computer was fighting to control it with the grid fins.They don't (or didn't at least) do an entry burn, unlike Falcon 9. I expect the fuel was getting swilled around the walls, which led to fuel starvation and a cascade RUD of the engines & booster. No more than 3 of the 13 engines that were supposed to relight managed to do so at any one time.
The ship was also spinning around like a drunken sailor. It seems to have lost attitude controls before it started reentry and without that it wasn't going to last very long. They also didn't do the planned on-orbit engine relight due to the ship's rolling. The last telemetry they received was at 49 minutes into the flight.
So plenty for them to work on before the next attempt.
Elon said they wanted to launch 6 of them this year. I think that's a little ambitious, but I wouldn't be surprised if they did 4 more in the remaining 9 months. I believe they have 4 unused Starship boosters and ships waiting to go. So, short of major redesigns, they can all be prepared in a matter of months to launch. The factory is being fitted out to produce more, but they're basically idling right now. They make one Raptor engine per day on average, but demand doesn't dictate a higher rate yet.
I'm sure they have access to state of the art computer modelling, but there's no substitute for practical experience. They will have got masses of data from the last launch, which will all inform the design and planning of future flights.
The booster didn't plough directly into the sea by the way. At least not in one piece - It blew up before that. It wasn't the flight termination system that did it either, as you can hear the "FTS is safed" call out on the commentary. SpaceX said it blew up about 462 meters above the water. It looks like it was unstable & the flight computer was fighting to control it with the grid fins.They don't (or didn't at least) do an entry burn, unlike Falcon 9. I expect the fuel was getting swilled around the walls, which led to fuel starvation and a cascade RUD of the engines & booster. No more than 3 of the 13 engines that were supposed to relight managed to do so at any one time.
The ship was also spinning around like a drunken sailor. It seems to have lost attitude controls before it started reentry and without that it wasn't going to last very long. They also didn't do the planned on-orbit engine relight due to the ship's rolling. The last telemetry they received was at 49 minutes into the flight.
So plenty for them to work on before the next attempt.
Starship 29, the next one to launch, did a full 6-engine static fire earlier. Seems to have gone OK.
Meanwhile, the Falcon 9s have been racking up the flights.
Yesterday Falcon 9 booster B1060 completed its 19th flight (Starlink). They have 3 boosters on 19 flights now: B1060, B1061 and B1062. There's a couple more on 17 flights too: B1063, B1067
B1078 is due off tonight on its 8th flight (Starlink) That'll be the 30th SpaceX launch this year already.
Meanwhile, the Falcon 9s have been racking up the flights.
Yesterday Falcon 9 booster B1060 completed its 19th flight (Starlink). They have 3 boosters on 19 flights now: B1060, B1061 and B1062. There's a couple more on 17 flights too: B1063, B1067
B1078 is due off tonight on its 8th flight (Starlink) That'll be the 30th SpaceX launch this year already.
Edited by Beati Dogu on Monday 25th March 22:45
Beati Dogu said:
They basically have an expendable rocket already. They cut the burn short to deliberately not orbit the ship. The hard part is of course the reuse.
Everyone on this thread will already know this, but for those just browsing, as of now, superheavy (the starship booster) isn't expected to be used in an expendable mode. If it were, it'd be rated at of putting 250t into low earth orbit. Reusable, the whole system is "only" rated to 150t per mission.The current spec of the international space station weighs 450t, and it took about 40 missions to build. Obviously it'd look different for geometry reasons but it's sort of shocking to me that something of that mass could be replaced in two expendable or three reusable launches of starship.
The other thing is that those numbers are with Raptor engines running at a nominal 230t of thrust per engine.
Not all raptors are built the same (there are sea-level and vacuum nozzles, as well as differences in the gimballing versus non-gimballing performance), but:
- On the test stand a year ago they ran one for a full burn duration at 269t (that was the test with 350 bar chamber pressure)
- If that thrust was available on all the engines in a full config, starship could launch 300t expendable, or about 170t reusable
At 300t you could probably build it out of -effectively- a grain silo rather than a carbonfibre and whipple shield tank if you wanted to.
CraigyMc said:
Everyone on this thread will already know this, but for those just browsing, as of now, superheavy (the starship booster) isn't expected to be used in an expendable mode. If it were, it'd be rated at of putting 250t into low earth orbit. Reusable, the whole system is "only" rated to 150t per mission.
The current spec of the international space station weighs 450t, and it took about 40 missions to build. Obviously it'd look different for geometry reasons but it's sort of shocking to me that something of that mass could be replaced in two expendable or three reusable launches of starship.
The other thing is that those numbers are with Raptor engines running at a nominal 230t of thrust per engine.
Not all raptors are built the same (there are sea-level and vacuum nozzles, as well as differences in the gimballing versus non-gimballing performance), but:
At 300t you could probably build it out of -effectively- a grain silo rather than a carbonfibre and whipple shield tank if you wanted to.
Thrust isn't the be-all and end all of efficiency (it definitely helps during the ascent phase to minimise gravity losses), but higher chamber pressures typically mean higher ISP.The current spec of the international space station weighs 450t, and it took about 40 missions to build. Obviously it'd look different for geometry reasons but it's sort of shocking to me that something of that mass could be replaced in two expendable or three reusable launches of starship.
The other thing is that those numbers are with Raptor engines running at a nominal 230t of thrust per engine.
Not all raptors are built the same (there are sea-level and vacuum nozzles, as well as differences in the gimballing versus non-gimballing performance), but:
- On the test stand a year ago they ran one for a full burn duration at 269t (that was the test with 350 bar chamber pressure)
- If that thrust was available on all the engines in a full config, starship could launch 300t expendable, or about 170t reusable
At 300t you could probably build it out of -effectively- a grain silo rather than a carbonfibre and whipple shield tank if you wanted to.
Strip off the flaps and the heat shielding would save substantial mass, full burn, it's a beast.
Remember a complete Apollo spacecraft is 46 tonnes, although the Saturn V's launch architecture had the S-IVB doing the TLI - it was 140t to LEO, 52t to TLI.
300t is more than double the capacity of a Saturn V.
CraigyMc said:
Beati Dogu said:
They basically have an expendable rocket already. They cut the burn short to deliberately not orbit the ship. The hard part is of course the reuse.
Everyone on this thread will already know this, but for those just browsing, as of now, superheavy (the starship booster) isn't expected to be used in an expendable mode. If it were, it'd be rated at of putting 250t into low earth orbit. Reusable, the whole system is "only" rated to 150t per mission.The current spec of the international space station weighs 450t, and it took about 40 missions to build. Obviously it'd look different for geometry reasons but it's sort of shocking to me that something of that mass could be replaced in two expendable or three reusable launches of starship.
The other thing is that those numbers are with Raptor engines running at a nominal 230t of thrust per engine.
Not all raptors are built the same (there are sea-level and vacuum nozzles, as well as differences in the gimballing versus non-gimballing performance), but:
- On the test stand a year ago they ran one for a full burn duration at 269t (that was the test with 350 bar chamber pressure)
- If that thrust was available on all the engines in a full config, starship could launch 300t expendable, or about 170t reusable
At 300t you could probably build it out of -effectively- a grain silo rather than a carbonfibre and whipple shield tank if you wanted to.
https://en.wikipedia.org/wiki/S-IVB
Maybe recommissioning Apollo hardware would be a quicker way to get back to the moon than all this refueling malarky.
An unused one became Skylab.
Eric Mc said:
NASA did definitely look at bringing back a modernised Saturn V but they decided that the technology, materials and, more importantly, the people involved in its design and construction were no longer around to make it practical.
Sorry I was thinking specifically of the Saturn third stage being the Starship payload, rather than recreating a whole Saturn V.The Saturn third stage (the SIVB) was part of the Saturn V so it was part of the revived Saturn V design. A key to the new Saturn V would have been new and improved J2 engines. The J2 engine was used to power both the second and third stages of the Saturn V. It was a liquid oxygen/hydrogen engine - so quite advanced. The proposed new J2 version was called the J2X.
However, the decision was made to proceed with Shuttle era technology rather than Saturn era technology.
However, the decision was made to proceed with Shuttle era technology rather than Saturn era technology.
CraigyMc said:
Hammersia said:
I'm a little surprised - and this is not a criticism - that on first glance the major issues they had on the last flight (loss of control, aero instability, ?frozen thrusters) are things that they had already solved on Falcon, or are things that you would imagine could have been simulated on their super duper turbo CAD / FEA software.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
Conspiracy theory - they like the drama and publicity of continuous rapid failure and development.
- Falcon doesn't use methane as fuel Starship does -- kerosene isn't as hard to manage as liquid methane.
- Falcon upper stage uses bottled nitrogen cold gas thrusters for control, Starship uses autogenous thrusters (gas from the primary tanks)
- Falcon upper stage has no fuel transfer capability, Starship does (demo'ed on IFT3). This changes mass distribution/balance.
- Falcon upper stage isn't reusable, so it has no re-entry capability, Starship is built with tiles to do this.
Starship development is going unbelievably well, especially given the timelines and costs.
I read somewhere the other day that Raptor 3 is currently about $250K per unit, fully reusable.
33 of them on the bottom of the superheavy booster is therefore in the region of $8.25m in motors.
A single RS25 for SLS is in the region of $100m -- SLS needs 4 of these per launch, so $400m in motors, not-reusable -- and this for a motor whose development was paid for decades ago.
It's not just technology they are getting right at SpaceX. Production manufacturing at this scale without enormous costs is really impressive.
An aero engine typically costs $2-3 million per tonne.
I can see an argument that more of the rocket engine is dumb static components but I still can't see you getting changed from a million dollars. I note that the source of the 250k is a future aspiration from SpaceX.
Gassing Station | Science! | Top of Page | What's New | My Stuff