totm nov 2023 SpaceX Discussion Thread

[NSEP]

5 minutes ago, sh1pman said:

Moon landing can be done with 2 FH launches (lander and cryogenic transfer stage with IDA, like DCSS) and one F9 launch (Dragon V2 with crew).

They'd need to redesign the heat shield to enable reentry from Moon orbit, and make a new lander. 

KSP RO isn't entirely unrealistic. Elon Musk's mind is on BFR, with these kinds of missions, but i doubt this kind of mission is going to happend using the Falcons. But it is definitely possible.

[sh1pman]

1 minute ago, NSEP said:

KSP RO isn't entirely unrealistic. Elon Musk's mind is on BFR, with these kinds of missions, but i doubt this kind of mission is going to happend using the Falcons. But it is definitely possible.

Yea, I think I got the idea from this very video. 

[Wjolcz]

1 hour ago, sh1pman said:

Moon landing can be done with 2 FH launches (lander and cryogenic transfer stage with IDA, like DCSS) and one F9 launch (Dragon V2 with crew).

They'd need to redesign the heat shield to enable reentry from Moon orbit, and make a new lander. 

I thought the heat shield is already able to withstand interplanetary reentries? Or is the shape wrong? IIRC Apollo used its like a wing and Souyz does the same.

Edited May 6, 2018 by Wjolcz

[hms_warrior]

I think 13 FH for one SLS is the wrong comparison.

The real question is:

"How many Marsrover /Europalander etc. can NASA build (and launch on comercial rockets) for the SLS money."

Cause it should not be NASAs job to build rockets, but payloads!

[sevenperforce]

2 hours ago, sh1pman said:

Moon landing can be done with 2 FH launches (lander and cryogenic transfer stage with IDA, like DCSS) and one F9 launch (Dragon V2 with crew).

They'd need to redesign the heat shield to enable reentry from Moon orbit, and make a new lander. 

The Dragon 2 heat shield is already going to be rated for cislunar return.

[NSEP]

36 minutes ago, hms_warrior said:

I think 13 FH for one SLS is the wrong comparison.

The real question is:

"How many Marsrover /Europalander etc. can NASA build (and launch on comercial rockets) for the SLS money."

Cause it should not be NASAs job to build rockets, but payloads!

NASA can make 0.8 curiosity rovers, 4 InSight landers or 0.6 cassini missions. NASA probably can't do any 'groundbreaking' missions like Europa landers and Mars rovers with yearly SLS money, they can however do Mars lander missions with a Sojouner-like rover. They should make a small Moon lander, we haven't been there in a while now, and just because "we have already been there" doesn't mean we have explored all of it. They should do a mission to the craters on the poles, were there is waterice.

Oh wait, this is an SpaceX thread...

Well, if only you can make money by exploring planets somehow... hmmmm.

Edited May 6, 2018 by NSEP

[sevenperforce]

2 hours ago, sh1pman said:

2 hours ago, NSEP said:

KSP RO isn't entirely unrealistic. Elon Musk's mind is on BFR, with these kinds of missions, but i doubt this kind of mission is going to happend using the Falcons. But it is definitely possible.

Yea, I think I got the idea from this very video. 

The bit presented wouldn't work for two reasons: first, the AJ-10 is too large to fit inside a Dragon 2 trunk with any reasonable volume for propellant, and second, SpaceX pads will never be plumbed for hydrogen as required if they were putting an RL-10 on top.

But not insurmountable problems.

[Canopus]

2 hours ago, NSEP said:

They should do a mission to the craters on the poles, were there is waterice.

Stuff like this seems to be already planned.

[NSEP]

11 minutes ago, Canopus said:

Stuff like this seems to be already planned.

Chandrayaan 2?

[Canopus]

25 minutes ago, NSEP said:

Chandrayaan 2?

Russia wants to send Luna 25 and 27, ESA wants to do fly an ISRU demonstration and the sample return mission, and while NASA's lunar rover was cancelled recently they still want to send experiments on commercial landers. And then you have India with Chandrayaan 2 and Chinas upcoming Chang'e missions. The moon will become a busy place again soon even if only half these missions actually leave the ground.

[wumpus]

17 hours ago, tater said:

FH is listed as 90M$ on their site, and the stats are for an expendable vehicle. Even at 150 M$/launch, SLS costs 17 FH launches (or 27 @ 90M). That's just for the keep the lights on program costs of 2.5 B$ a year.

All that said, FH is not as useful as it looks, except for space probes, since the bulk of the mass to space is stage 2 propellants.

This would be utterly useless for NASA. Electron can't do anything useful, really.

NASA should be about larger payloads, not cubesats.

The electron rocket isn't very useful for NASA (although I think they still launch sounding rockets, so don't entirely count them out).  The Rutherford engine on the other hand could very well be the next landing motor.  I'd certainly expect an electric motor to be more reliable on the restart than any turbine powered turbopump, although it will have a harder road beating pressurized hypergolics (especially with fancy new carbon pressurized fuel tanks).

Of course, this being a spacex thread, I have no idea if that would be a sufficient reason for spacex to buy them: I'd expect them to want to use Raptor engines to land on Mars, rutherfords seem more geared to lunar use.  I thought there was a company built around pressurized motors that went into bankruptcy (or at least didn't successfully launch rockets).  If they had the pressurized tanks (cheap), they might be an acquisition target (again, more for lunar missions.  So I wouldn't expect Musk to buy them  without an Moon landing contract in hand).

[XB-70A]

Just coming back from Playa'. 

The tree branch is free and the fledgling has returned to the nest.

 

 

Also, totally unofficial, but the company has been renamed GraceX.

[IncongruousGoat]

5 hours ago, wumpus said:

The Rutherford engine on the other hand could very well be the next landing motor.  I'd certainly expect an electric motor to be more reliable on the restart than any turbine powered turbopump, although it will have a harder road beating pressurized hypergolics (especially with fancy new carbon pressurized fuel tanks).

No, not really, for a few reasons. First off, the propellant is problematic. Kerolox is hard to store over long periods of time, and harder to start on-demand, which is not what you want in a landing engine. More importantly, though, Rutherford doesn't have any throttling or restart capability, much less the kinds of deep throttling one would want for a lander. Sure, with good (read: pin-point accurate) guidance it's possible to try and do a perfect suicide burn, but doing so would be rather dangerous with engines that can only start once and have no throttling capability at all, even if you're landing in a well-characterized location (which is by no means guaranteed).

And, before anyone suggests it, adding deep throttling to an engine that wasn't designed for it from the beginning is akin to redesigning the engine completely. SpaceX only managed to get Merlin throttling down to 40% due to careful planning and massive increases in engine performance over its development.

[NSEP]

I wonder what SpaceX will achieve in the next 16 years. Maybe they will build the ITS after the BFR. hmmmmmmmmmmm.

[sh1pman]

50 minutes ago, NSEP said:

Maybe they will build the ITS after the BFR.

ITS is ridiculous. Unless you have regular flights to other planets, you don’t need to go bigger than BFR. And if there’s a need to put half a kiloton in orbit in one go (very unlikely), then BFR Heavy is more practical. ITS will need new tooling as well. Don’t think ITS will happen.

[DAL59]

34 minutes ago, sh1pman said:

FR Heavy is more practical. ITS will need new tooling as well. Don’t think ITS will happen

Which means... ITS HEAVY

Edited May 6, 2018 by DAL59

[NSEP]

1 hour ago, sh1pman said:

ITS is ridiculous. Unless you have regular flights to other planets, you don’t need to go bigger than BFR. And if there’s a need to put half a kiloton in orbit in one go (very unlikely), then BFR Heavy is more practical. ITS will need new tooling as well. Don’t think ITS will happen.

ITS isn't much more ridiculous other than it being bigger than the BFR. In the future, when BFR is going to do its job nice and well, scaling up would be the logical next step for space colonization. ITS could carry more people for a cheaper price to other celestial bodies, wich comes in handy when more and more people want to go to space hotels, and when you actually want to send millions of people to Mars in the future.

BFR heavy is more impractical than the ITS to be honest, keep in mind that the most important thing about the BFR is the BFS, not the booster. A BFR heavy can send more payload to orbit than a regular BFR for sure, but the return mass and payload volume is still the same. An ITS would have a more advantages that a BFR heavy, and it would definitely be worth building new tooling and facilities for.

I don't think its impossible for the ITS to be built 15-20 years after the BFR. 

Edited May 7, 2018 by NSEP

[tater]

Looks like launch no sooner than Wednesday. NOTAMs for Monday and Tuesday have been pulled.

[Bill Phil]

1 hour ago, sh1pman said:

ITS is ridiculous. Unless you have regular flights to other planets, you don’t need to go bigger than BFR. And if there’s a need to put half a kiloton in orbit in one go (very unlikely), then BFR Heavy is more practical. ITS will need new tooling as well. Don’t think ITS will happen.

Once they get the experience with BFR it's just a matter of tooling and putting enough resources behind development. I think that BFR is really serving more as a technology demonstrator for ITS that can still earn them revenue, and that ITS is still being planned, if not for the near future. It likely will undergo redesigns, but we may see something like a 12 meter BFR flying in 30 years, provided everything goes swimmingly (there's a good likelihood that it won't).

They may yet use a cluster of BFR boosters to push a scaled up BFR into a trajectory that it can get to orbit from. Provided they design the boosters for that in the first place.

It would probably have more to do with downmass than upmass. Landing more mass is always a plus.

[StrandedonEarth]

6 minutes ago, Bill Phil said:

They may yet use a cluster of BFR boosters to push a scaled up BFR into a trajectory that it can get to orbit from. Provided they design the boosters for that in the first place.

Or just to get a full BFS into orbit, instead of having to refuel it before it can leave LEO.

[sh1pman]

14 minutes ago, Bill Phil said:

12 meter BFR flying in 30 years, provided everything goes swimmingly (there's a good likelihood that it won't).

They may scale up the BFR. I was talking about the 2016 IAC design. The reason why I don't think it's going to happen is because BFR itself is an evolution of that ITS design. It has a delta wing, better fueling/refueling/docking mechanism, probably a lot of other improvements. Returning to the ITS design as it was presented in 2016 will be a downgrade, but improving upon the BFR design with possible increase in size can be a very sensible thing to do (assuming the design works, of course).

Edited May 7, 2018 by sh1pman

[Bill Phil]

37 minutes ago, StrandedonEarth said:

Or just to get a full BFS into orbit, instead of having to refuel it before it can leave LEO.

That's something like over a thousand tonnes, right? At that point you'd have... well, some serious capability. I'd be launching a lot more than a fully fueled BFS, that's for sure...

31 minutes ago, sh1pman said:

They may scale up the BFR. I was talking about the 2016 IAC design. The reason why I don't think it's going to happen is because BFR itself is an evolution of that ITS design. It has a delta wing, better fueling/refueling/docking mechanism, probably a lot of other improvements. Returning to the ITS design as it was presented in 2016 will be a downgrade, but improving upon the BFR design with possible increase in size can be a very sensible thing to do (assuming the design works, of course).

Yeah, the original ITS design would be a downgrade. It was an early design concept regardless. I do think a scaled up BFR might make an appearance, depending on the circumstances.

[tater]

 

 NET Thursday.

[tater]

I want them to get this right, but I'm jonesing for a rocket landing.

[Val]

I moved some off topic posts from Thursday.