Speculation thread: intermediate-lift Raptor-derived RLV

[J-V]

No, you are wrong. Mueller said ITS (family) would make all other rockets obsolete.

Falcon 9 is already making other rockets obsolete. ITS will do the same to Falcon 9, eventually.

As always, actually listening to the source material is important. What Tom said clearly indicated that their intention is to make Falcon 9, Falcon Heavy and all their competitors obsolete. It's actually the first time I've ever heard someone from SpaceX give a hint to their game plan - they really do intend to move to full reusability, even if it means flying today's tiny payloads on a monster like ITS. I guess I can imagine an ITS flight to GEO being cheaper than a Falcon 9 / Heavy flight - fuel is cheaper than hardware, especially if the touch labour of ITS really is as low as they intend (which is another point Tom made in that recording.) If fully reusable vehicles smaller than ITS are possible, I don't know how they can continue competing with a bigger vehicle, but by then perhaps the market will have changed and customers will be demanding bigger payloads.

If ITS is as cheap as SpaceX hopes, wouldn't it then just be cheaper to design GEO birds with much bigger fuel tanks, lift them to LEO and let them get to the correct orbit by themseles? No point lifting the heavy BFS up to GEO if the payload can do it. Raptor has better ISP than pressure fed engines in satellites, but payload fractions are a bit better for the satellite only. (anyone willing to spend a bit of time and make a BOTE calculation of this?)

[macpacheco]

No, you are wrong. Mueller said ITS (family) would make all other rockets obsolete.

Falcon 9 is already making other rockets obsolete. ITS will do the same to Falcon 9, eventually.

As always, actually listening to the source material is important. What Tom said clearly indicated that their intention is to make Falcon 9, Falcon Heavy and all their competitors obsolete. It's actually the first time I've ever heard someone from SpaceX give a hint to their game plan - they really do intend to move to full reusability, even if it means flying today's tiny payloads on a monster like ITS. I guess I can imagine an ITS flight to GEO being cheaper than a Falcon 9 / Heavy flight - fuel is cheaper than hardware, especially if the touch labour of ITS really is as low as they intend (which is another point Tom made in that recording.) If fully reusable vehicles smaller than ITS are possible, I don't know how they can continue competing with a bigger vehicle, but by then perhaps the market will have changed and customers will be demanding bigger payloads.

If ITS is as cheap as SpaceX hopes, wouldn't it then just be cheaper to design GEO birds with much bigger fuel tanks, lift them to LEO and let them get to the correct orbit by themseles? No point lifting the heavy BFS up to GEO if the payload can do it. Raptor has better ISP than pressure fed engines in satellites, but payload fractions are a bit better for the satellite only. (anyone willing to spend a bit of time and make a BOTE calculation of this?)

No because each satellite needs its own separate fuel tank. SpaceX only needs extra capacity on its launch vehicles that will be reused hundreds of times (upper stage) or a thousand time (booster). Plus so far, SpaceX can do things much cheaper than satellite makers.

[envy887]

From LEO to GEO and back to Earth surface is further than going from LEO to Mars' surface in Delta-v​ terms. It's 6.6 km/s vs about 5.0 km/s for landing on Mars.

Even a vehicle with ITS mass fractions and Raptor performance can't do that in a single launch with full reuse. ITS only has about 4.1 km/s after launch, even with no payload.

Even with Raptor performance, you have to stage somewhere. Maybe it will be cheap enough to refuel instead, but I think that's unlikely to happen before something like the full ITS system is operating.

[Robotbeat]

Direct to Mars is something Falcon 9 can do. Subscale ITS could refuel, of course. But anyway, direct GSO is very rare. Trips to GTO should be just fine until refueling becomes more common.

[envy887]

Direct to Mars is something Falcon 9 can do. Subscale ITS could refuel, of course. But anyway, direct GSO is very rare. Trips to GTO should be just fine until refueling becomes more common.

Falcon can't do direct to Mars surface with any substantial payload and with full reuse, which is the underlying assumption here. Mars injection is much easier than GEO and back... even Mars landing is easier than GEO and back.

Refueling in LEO changes everything.

Fully refueled in LEO, the full-size ITS spaceship can take ~475 tonnes to GEO and return to Earth's surface empty. Launch + refueling takes 6 launches, so that's ~80 tonnes of payload to GEO per launch with full reuse.

A subscale ITS could do a commensurate amount, e.g. ~30 tonnes for a 14 Raptor booster, and ~20 tonnes for a 9 Raptor booster. It just takes some on-orbit propellant and payload handling, of course.

[gospacex]

To me, plausible future development looks like this:

F9/FH continue to fly, with increased frequency, bringing $$$ to SpaceX and accumulating reuse experience.

SpaceX builds a new factory, sized for ITS. Naturally, stages won't be road-transported from it (likely barge transport).

SpaceX continues to develop Raptor and ITS and chooses where it wants to have ITS-capable pads.

SpaceX looks into feasibility of having a larger diameter (say, 5.2m, same as current fairing), possibly fiber-wound upper F9/FH stage (higher payloads from the same pads). If they decide they want it, it is built in the new factory. (Hawthorne factory is busy cranking out F9 boosters, "normal diameter" second stages, and Merlins, has no capabilities to build large fiber-wound tanks, and transportation from there is more difficult).

SpaceX looks into feasibility of having "small Raptor" (about same as Merlin-1, i.e. 100ton thrust engine). If they decide they want it, it powers a methane upper stage of F9/FH.

ITS pads are complete. ITS first flights after 5+ years of development. F9/FH still continues to launch, bringing $$$ to SpaceX.

ITS takes some load off F9/FH. SpaceX assesses whether it wants to fly exclusively ITS (this, for example, means that some pads should be abandoned, since they can't be converted to ITS); or that it also wants to have a smaller rocket. If it wants that, a successor to F9 booster is developed: larger diameter (say, 5.2m) first stage using the same tech as ITS (if current plans hold, it would be fiber-wound tankage and Raptors). Pads are converted piecemeal to this 5.2m rocket.

F9/FH and Merlins are phased out.

[wannamoonbase]

To me, plausible future development looks like this:

F9/FH continue to fly, with increased frequency, bringing $$$ to SpaceX and accumulating reuse experience.

SpaceX builds a new factory, sized for ITS. Naturally, stages won't be road-transported from it (likely barge transport).

SpaceX continues to develop Raptor and ITS and chooses where it wants to have ITS-capable pads.

SpaceX looks into feasibility of having a larger diameter (say, 5.2m, same as current fairing), possibly fiber-wound upper F9/FH stage (higher payloads from the same pads). If they decide they want it, it is built in the new factory. (Hawthorne factory is busy cranking out F9 boosters, second stages and Merlins, has no capabilities to build large fiber-wound tanks, and transportation from there is more difficult).

SpaceX looks into feasibility of having "small Raptor" (about same as Merlin-1, i.e. 100ton thrust engine). If they decide they want it, it powers a methane upper stage of F9/FH.

ITS pads are complete. ITS first flights after 5+ years of development. F9/FH still continues to launch, bringing $$$ to SpaceX.

ITS takes some load off F9/FH. SpaceX assesses whether it wants to fly exclusively ITS (this, for example, means that some pads should be abandoned, since they can't be converted to ITS); or that it also wants to have a smaller rocket. If it wants that, a successor to F9 booster is developed: larger diameter (say, 5.2m) first stage using the same tech as ITS (if current plans hold, it would be fiber-wound tankage and Raptors). Pads are converted piecemeal to this 5.2m rocket.

F9/FH and Merlins are phased out.

I think you are close but have too many steps. 

1) I think the Block 5 F9/FH become operational and fly often, making money and gaining experience.

2) They move on to developing a fully reuseable 2 stage raptor powered vehicle.

3) Since the new vehicle is to be fully reuseable they won't need to build many of them.  I won't be surprised if they keep that in Hawthorn then ship by sea and test at the launch site.

4) Launch sites will be Florida or VAFB.  A 10,000,000 lbf vehicle needs a lot of space from populations.  Also, need to be close to big dollar Government payloads (like NASA)

5) I can see SpaceX building a ground up fresh launch and landing pad for this vehicle. 

6) Start flight testing without customers in the loop.  Fully vet the vehicle before putting it into service.

F9 and FH will have a  busy future for the next 5+ years while this happens.

[envy887]

...If it wants that, a successor to F9 booster is developed: larger diameter (say, 5.2m) first stage using the same tech as ITS (if current plans hold, it would be fiber-wound tankage and Raptors). Pads are converted piecemeal to this 5.2m rocket.
...

They won't want it. The only time for an intermediate methane vehicle is before the full Mars architecture is operating. "ITS will obsolete every existing rocket."

[gospacex]

...If it wants that, a successor to F9 booster is developed: larger diameter (say, 5.2m) first stage using the same tech as ITS (if current plans hold, it would be fiber-wound tankage and Raptors). Pads are converted piecemeal to this 5.2m rocket.
...

They won't want it. The only time for an intermediate methane vehicle is before the full Mars architecture is operating. "ITS will obsolete every existing rocket."

Plans change. Sometime ago SpaceX thought RP-1 is the best fuel for a booster.

[gospacex]

3) Since the new vehicle is to be fully reuseable they won't need to build many of them.

That's wishful thinking. Remember how NASA was agonizing whether to build another Shuttle when it lost one? It's best to assume that you will lose some number of them, and to be prepared to build more, rather than fewer of them.

I won't be surprised if they keep that in Hawthorn then ship by sea and test at the launch site.

To me, it looks like 12m dia stage won't even fit inside Hawthorne building...

[rsdavis9]

I thought hawthorne had room to expand. I read somewhere that there is empty buildings next door.

[wannamoonbase]

3) Since the new vehicle is to be fully reuseable they won't need to build many of them.

That's wishful thinking. Remember how NASA was agonizing whether to build another Shuttle when it lost one? It's best to assume that you will lose some number of them, and to be prepared to build more, rather than fewer of them.

I won't be surprised if they keep that in Hawthorn then ship by sea and test at the launch site.

To me, it looks like 12m dia stage won't even fit inside Hawthorne building...
 

I didn't say build just 1 or build a few and stop.  More likely, build, test, refine, build, test, repeat.  SpaceX has been very iterative so far, why change.

Regarding Hawthorne, I very intentionally didn't say the same building.  Compared to rockets, buildings are cheap and easy to build.  Transporting and shipping will be hard, but using your skilled and experience team and being on site with them has huge advantages.

[gospacex]

Regarding Hawthorne, I very intentionally didn't say the same building.  Compared to rockets, buildings are cheap and easy to build.

In other words, you "disagreed" with me but in fact, you agree with me: a new factory makes more sense than cramming ITS into existing F9 factory. A new factory somewhere near the current one is still a new factory.

[Lars-J]

I thought hawthorne had room to expand. I read somewhere that there is empty buildings next door.

Yes, but they won't be able to road transport 12m diameter stages in and out of there. But there is no point to discuss this - they have already stated that BFR/ITS will be built near the launch site.

That doesn't mean that Hawthorne will be doing nothing. Engines and sub components can be built there, and assembled by the launch site.

[rsdavis9]

Yes, but they won't be able to road transport 12m diameter stages in and out of there. But there is no point to discuss this - they have already stated that BFR/ITS will be built near the launch site.

That doesn't mean that Hawthorne will be doing nothing. Engines and sub components can be built there, and assembled by the launch site.

So basically composite layup and assembly of components will be done near launch site.
All else could  be done in hawthorne.

[wannamoonbase]

Regarding Hawthorne, I very intentionally didn't say the same building.  Compared to rockets, buildings are cheap and easy to build.

In other words, you "disagreed" with me but in fact, you agree with me: a new factory makes more sense than cramming ITS into existing F9 factory. A new factory somewhere near the current one is still a new factory.

Fair enough, I'm not trying to argue. 

As I mentioned in my first post, I agree with much of what you said, but not everything.

[spacenut]

Building near the launch site means, no long river/inter-coastal waterway transport that takes weeks to get there.  Therefore, it will be built near or at the Cape, or Boca Chica. 

[envy887]

Building near the launch site means, no long river/inter-coastal waterway transport that takes weeks to get there.  Therefore, it will be built near or at the Cape, or Boca Chica.

Musk said they looked at Michoud for manufacturing. I don't think they have any qualms about barging parts around if needed.

[spacenut]

Michoud is only going to make one SLS per year, maybe 2.  They can manufacture more, so building a reusable ITS or Mini-ITS per year would not be out of the question.  If they can do two of the ITS family, a fleet can slowly be built since it is supposed to be reusable.  Shifts can be added, and weekend shifts to increase productivity and economy of scale. 

[macpacheco]

Hawthorne isn't very practical even for 5.2m diameter stages. Beyond 5.2 meters then its downright 100% illogical.
Its been acknowledged by SpaceX a thicker rocket would most likely be built in Brownsville, near Boca Chica and much easier to transport to Florida instead of having to go the long way through the Panama canal.
Hawthorne likely would only build engines, sub assemblies, specialty parts.
The model of building rockets in Hawthorne made sense with high volume construction of road transportable stages. 5.2m, 8m or 10m rockets will not be high volume nor road transportable.