Speculation thread: intermediate-lift Raptor-derived RLV

[Robotbeat]

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

[envy887]

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.

[RDMM2081]

I also suggest thinking about launch pad congestion if the predicted launch volume materializes.
F9/FH are stepping stones onto large raptor rockets, they are not going to hang around once mini ITS is flying and its certified with NASA/USAF.

Wrong.
F9/FH is the only thing which makes SpaceX money at the moment. They are "cash cows".

I've often wondered if there is a lesson to be learned by the 2008-2009 timeframe, when SpaceX's only successful launch vehicle, the Falcon 1, was retired.  I always thought it "made sense" for them to keep a skeleton crew equivalent on producing and launching Falcon 1 while re tasking the majority of the workforce onto the Falcon 9.  Maybe there simply wasn't enough manpower, maybe the investment in infrastructure to keep launching that vehicle wasn't profitable enough, maybe they just didn't want to spend ANY money on an "obsolete" launcher.  But Falcon 1 represented a class of launcher that other companies are still trying to replicate TODAY, I think there was at least a market for a few launches a year.

The point in relationship to this thread being: They already abandoned a successful vehicle once when something better was in the pipeline, they don't seem to believe in wasting any more effort on the pathfinder than absolutely necessary.

Cash Cows, indeed, and I do believe the demise of the Falcon class is not imminent, but certainly it WILL happen at some point.

[RocketmanUS]

Raptor reusable 1st stage 9 engines, expendable US 1 engine and a reusable US similar to BFS OML. It' s performance would only need to replace F9/FH for payloads needed at a lower cost, not the full performance mass to LEO or GTO. Distributed launch could take greater mass to GTO.

I would expect this rocket to test out new tech ( tanks ect. ) for the ITS and at some point replace F9/FH. I expect it will evolve over time and use a new launch pad designed for it.

[Lars-J]

I always thought it "made sense" for them to keep a skeleton crew equivalent on producing and launching Falcon 1 while re tasking the majority of the workforce onto the Falcon 9.  Maybe there simply wasn't enough manpower, maybe the investment in infrastructure to keep launching that vehicle wasn't profitable enough, maybe they just didn't want to spend ANY money on an "obsolete" launcher.  But Falcon 1 represented a class of launcher that other companies are still trying to replicate TODAY, I think there was at least a market for a few launches a year.

No. If they had lots of customers, they would have kept Falcon 1. But there wasn't sufficient demand. The reason that so many new startups are trying to build a Falcon 1 like LV is not because there is a great market - It is because they need to start somewhere. The myth about a massive micro/mini payload market just needs to die. The Falcon 1 existed, and they didn't show up.

[envy887]

Raptor reusable 1st stage 9 engines, expendable US 1 engine and a reusable US similar to BFS OML. It' s performance would only need to replace F9/FH for payloads needed at a lower cost, not the full performance mass to LEO or GTO. Distributed launch could take greater mass to GTO.

I would expect this rocket to test out new tech ( tanks ect. ) for the ITS and at some point replace F9/FH. I expect it will evolve over time and use a new launch pad designed for it.

There's little to be described as "intermediate" about a 9-Raptor vehicle. With dry mass per stage volume similar to Falcon it would (if fully expended) put ~120 tonnes to LEO and ~42 tonnes to GTO.

If they get as low as even 2x the dry mass fraction of ITS tanker it could lift ~31 tonnes (75+ CommX sats) to 1100 km and still recover both the booster and the upper stage. Even an AlLi alloy version would be a significant upgrade over FH in both capability and capacity.

[macpacheco]

Raptor reusable 1st stage 9 engines, expendable US 1 engine and a reusable US similar to BFS OML. It' s performance would only need to replace F9/FH for payloads needed at a lower cost, not the full performance mass to LEO or GTO. Distributed launch could take greater mass to GTO.

I would expect this rocket to test out new tech ( tanks ect. ) for the ITS and at some point replace F9/FH. I expect it will evolve over time and use a new launch pad designed for it.

There's little to be described as "intermediate" about a 9-Raptor vehicle. With dry mass per stage volume similar to Falcon it would (if fully expended) put ~120 tonnes to LEO and ~42 tonnes to GTO.

If they get as low as even 2x the dry mass fraction of ITS tanker it could lift ~31 tonnes (75+ CommX sats) to 1100 km and still recover both the booster and the upper stage. Even an AlLi alloy version would be a significant upgrade over FH in both capability and capacity.

A 1/3 scale ITS would have 14 engines on the first stage, not much bigger than 9.
The difference is being a mini ITS suggests the upper stage would also have lots of engines, something like 3 or more vacuum ones and at least one Sea level for landing.
It wouldn't be that much more powerful than a F9 style super sized rocket with 9+1 raptors. 30-50% more performance. Extra engines on the upper stage makes reusing it easier.

[RocketmanUS]

Raptor reusable 1st stage 9 engines, expendable US 1 engine and a reusable US similar to BFS OML. It' s performance would only need to replace F9/FH for payloads needed at a lower cost, not the full performance mass to LEO or GTO. Distributed launch could take greater mass to GTO.

I would expect this rocket to test out new tech ( tanks ect. ) for the ITS and at some point replace F9/FH. I expect it will evolve over time and use a new launch pad designed for it.

There's little to be described as "intermediate" about a 9-Raptor vehicle. With dry mass per stage volume similar to Falcon it would (if fully expended) put ~120 tonnes to LEO and ~42 tonnes to GTO.

If they get as low as even 2x the dry mass fraction of ITS tanker it could lift ~31 tonnes (75+ CommX sats) to 1100 km and still recover both the booster and the upper stage. Even an AlLi alloy version would be a significant upgrade over FH in both capability and capacity.

A 1/3 scale ITS would have 14 engines on the first stage, not much bigger than 9.
The difference is being a mini ITS suggests the upper stage would also have lots of engines, something like 3 or more vacuum ones and at least one Sea level for landing.
It wouldn't be that much more powerful than a F9 style super sized rocket with 9+1 raptors. 30-50% more performance. Extra engines on the upper stage makes reusing it easier.

The 9/1 engine is already known, they know the engine out pattern and how to land it. This would be a first step. Adding in to many engines makes the vehicle to big and to big a step forward. Just add some new like engine and stage material. This size is not to big or to small, let ITS be the bigger launcher and have both markets open. For the bigger launcher the main payload would be propellant and only the BFS needs that big a launchers. The is big enough if ITS is not developed soon to take crew to Mars ( exploration class that would be the first few trips anyway ).

So why go bigger than needed for an intermediate vehicle as a step to ITS and a cheaper than Falcon?

[docmordrid]

>
So why go bigger than needed for an intermediate vehicle as a step to ITS and a cheaper than Falcon?

To have a significantly larger reusable payload mass in their mainline launcher than New Glenn, or any upgrade of same. Or even New Armstrong. And as Tom Mueller said in his Skype talk,

Imagine if you had a launch vehicle that could put a few hundred tons into LEO for a few million dollars. It completely changes the game. Then you think about putting big satellites up there and being able to service them....

Or, with an Mk 41 VLS-like multiple deployment system and a bay door, entire constellation planes in one launch.

[gospacex]

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

Eventually. Not immediately.

[macpacheco]

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

Eventually. Not immediately.

Immediately there's only Block IV (in a few months for the full Block IV upgraded F9). FH and Block V is 6+ months away. Only M1D engine and RP1 fuel.
Raptor qualification is likely 12-18 months.
Any discussion about Raptor usage on any LV in an ideal best case is for 2019 and more likely 2020.

How Raptor will fit into a brand new rocket or a replacement F9/FH upper stage highly depends on its performance and most of all cost. There are still many unknowns.
It will also highly depend on how easily and IF SpaceX will manage to reuse a single engine upper stage (perhaps recover it but always with too much damage, we don't know).
It truly makes sense IF its the key to solving upper stage reuse. And manages to mostly or fully make up for lost performance due to reuse equipment mass.

[wannamoonbase]

A 1/3 scale ITS would have 14 engines on the first stage, not much bigger than 9.
The difference is being a mini ITS suggests the upper stage would also have lots of engines, something like 3 or more vacuum ones and at least one Sea level for landing.
It wouldn't be that much more powerful than a F9 style super sized rocket with 9+1 raptors. 30-50% more performance. Extra engines on the upper stage makes reusing it easier.

I'm wondering about the size a lot as well.  A center engine configuration is probably a given.  How many go in an outter ring(s) is another question.

What is going to the critical sizing criteria?  Useful payload for a fully reusable 2 stage vehicle, physical size, desire to build the largest rocket ever?

Since Mini-ITS as discussed is to b a development vehicle therefore I'd expect to see them put as much final ITS technology into the new vehicle, materials, engines, software, propulsive recovery of the US.

Unlike the F1, F5, F9 development periods, SpaceX has a lot of experience now and an operational vehicle that can pay the bills.

[RocketmanUS]

>
So why go bigger than needed for an intermediate vehicle as a step to ITS and a cheaper than Falcon?

To have a significantly larger reusable payload mass in their mainline launcher than New Glenn, or any upgrade of same. Or even New Armstrong. And as Tom Mueller said in his Skype talk,

Imagine if you had a launch vehicle that could put a few hundred tons into LEO for a few million dollars. It completely changes the game. Then you think about putting big satellites up there and being able to service them....

Or, with an Mk 41 VLS-like multiple deployment system and a bay door, entire constellation planes in one launch.

Could not find a usable link to the interview.

So do I understand that this would be in comparison 737 ( mini ITS ) and 747 ( ITS ) but no 10 passenger small jet ( Raptor 9/1 )?

[rakaydos]

So I just had a random brainstorm for a Raptor 1 rocket.

Single raptor lower stage, but the hot gas pressurant for the tanks is actually piped up to the upperstage for storage, then repressurize the lower stage tanks from above. After stage separation, that hot gas is used in one of the ITS 10 ton reaction thrusters as an upperstage engine.

The lower stage, using the pressurant remaining in the pipes, hoverslams at 10g+ into a net. (making z axis accuracy less important)

How would I check my math to see if this is reasonable?

[QuantumG]

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.

[macpacheco]

Could not find a usable link to the interview.

So do I understand that this would be in comparison 737 ( mini ITS ) and 747 ( ITS ) but no 10 passenger small jet ( Raptor 9/1 )?

Because aircraft are naturally reusable.
Rockets aren't.
Consider SpaceX is adding a lot of performance to F9 in order to leave margins for much softer booster recoveries. They want F9 boosters to land as nicely as they currently do on CRS missions, except still on ASDS for most GTO launches.
But that doesn't leave performance for the upper stage to be recovered.
If the upper stage recovery gear masses say, 3 tons, that's 3 tons you take away from payload capability to the target orbit.
That's likely doable for a CRS mission, because the target orbit is just 200x300Km, but even to a Iridium orbit 780km polar, current F9 cannot even (or at least barely) RTLS with Block III. Even with Block V, there might not be 3 tons left in payload capability for an Iridium launch.
As you move to GTO launches, taking 3 tons away from payload capability kneecaps F9 performance.

So you go to FH in order to recover the upper stage. Now you must refurb 3 boosters instead of 1. The center core is already somewhat complicated to recover, except for the lowest performance launches for FH capabilities.

Now you move to a Raptor 9 rocket, with 9 Raptors on the booster + a single Raptor upper stage.
The higher T:W and ISP allows the booster to deliver the US a bit faster and higher altitude.
The US, also with more T:W and ISP can still do everything F9 could do, even expendable Block V F9 (8300kg to GTO-1800m/s). It can do that with some excess margins.

But lets not ignore the fact that individual launches are a constraint on most ranges.
GEO/GTO missions are easy to multi manifest... If there's enough spare performance.

So a bigger rocket, with a few more booster engines and a diameter twice as large can lift a much bigger upper stage while still lifting off with faster acceleration than a F9, allowing it to carry around 3x as much propellant as a current F9 US, US perhaps have 4 engines (3 vacuum in an outer ring + a single SL for landing). The extra vacuum thrust allows the US to fly most of its ascent limited to max gs, brutally reducing gravity losses.

Raptor upper stages can be designed for ultra long coasting and very large number of restarts. This enables the upper stage to perform bi elliptical transfers, directly inserting themselves into GEO or near GEO orbits while still leaving fuel to return (to the pad or to an ASDS). While carrying multiple good size payloads per trip.

This would transform the GEO market. SpaceX would call their launch missions to GEO instead of GTO, and the reduced propellant / transit times would eliminate the heaviest mass item on GEO satellites, which doesn't add to revenue, the usual chemical apogee motor used to get to GEO faster.
For instance the Inmarsat 5F1/2/3 are listed as 6070kg launch mass but 3750kg BOL mass (beginning of mission), that suggests 38% of the satellite launch mass is spent transiting to GEO ! The same satellite if delivered to GEO (in the other side of the earth) could easily mass just 4000Kg instead !
If it can deliver 20 tons total payloads mass to GEO, that could mean 5 big satellites which usually mass over 6tons each.

And even more importantly the vast majority of satellite total cost until operation is building the satellite instead of launching it.
Dropping launch costs by 75% or more would put a lot of pressure on satellite manufacturing shops to totally rethink their designs, replacing ultra expensive parts with heavier/less robust ones. The goal would be to at least make satellites costs half as much as today.
For instance Dragon spacecraft uses commercial solar panels (the type used on land). Typical satellites use the really expensive panels which cost about 10x as much per Watt for just a mass savings of 50% per Watt ! That's just one easy example of how to make cheaper/heavier satellites instead.
With launch costs so cheap per ton to GEO, customers could opt to make satellites 3x or more the mass due to a combination of using heavier components, and adding more beams/solar panels/batteries/...

Right now SpaceX has a massive head start. Expending the F9/FH US for now doesn't break the bank. Better to jump straight for a much more capable, fully reusable rocket that is one order of magnitude cheaper for SpaceX to operate even compared with partially reusable Block V rockets (with 24h refurb for 10 launches, with a longer refurb each 10 launches), even if considering the total cost per launch, instead of cost per ton per launch (which could be two orders of magnitude cheaper than expendable F9 or 95% cheaper per ton than F9 Block V).

[hkultala]

But lets not ignore the fact that individual launches are a constraint on most ranges.
GEO/GTO missions are easy to multi manifest... If there's enough spare performance.

No, they are not easy. Arianespace does it, but only quite rarely, because they cannot find many satellites that can be dual-manifested.

[hkultala]

Could not find a usable link to the interview.

So do I understand that this would be in comparison 737 ( mini ITS ) and 747 ( ITS ) but no 10 passenger small jet ( Raptor 9/1 )?

Because aircraft are naturally reusable.
Rockets aren't.

There is no such "natural difference". A "natural aircraft" would not have a landing gear as it's only extra weight and complexity while it's in the air, so it would take off from a sled and perform a belly landing, suffering considerable damage.

Landing gears have been engineered to aircrafts to make them reusable, at the extra cost and complexity.

Consider SpaceX is adding a lot of performance to F9 in order to leave margins for much softer booster recoveries. They want F9 boosters to land as nicely as they currently do on CRS missions, except still on ASDS for most GTO launches.
But that doesn't leave performance for the upper stage to be recovered.
If the upper stage recovery gear masses say, 3 tons, that's 3 tons you take away from payload capability to the target orbit.
That's likely doable for a CRS mission, because the target orbit is just 200x300Km, but even to a Iridium orbit 780km polar, current F9 cannot even (or at least barely) RTLS with Block III. Even with Block V, there might not be 3 tons left in payload capability for an Iridium launch.

Are you sure it did not have the payload capacity to RTLS? What if it landed to the ship because the landing pad at Vandenberg was not yet ready?

The difference in required delta-v between 300km and 780km orbit is very small.

And if you don't have capacity for 1st stage RTLS + second stage landing, then you do 1st stage barge landing + second stage landing.

As you move to GTO launches, taking 3 tons away from payload capability kneecaps F9 performance.

So you go to FH in order to recover the upper stage. Now you must refurb 3 boosters instead of 1. The center core is already somewhat complicated to recover, except for the lowest performance launches for FH capabilities.

It you are at the edge of the capacity of Falcon 9, then it's so easy launch for FH that there is nothing complicated for center core recovery of FH. You have plenty of fuel for center core boostback.

FH centr core recovery only becomes harder when you start approaching the limits of FH performance, and center core has to fly much further away.

[macpacheco]

But lets not ignore the fact that individual launches are a constraint on most ranges.
GEO/GTO missions are easy to multi manifest... If there's enough spare performance.

No, they are not easy. Arianespace does it, but only quite rarely, because they cannot find many satellites that can be dual-manifested.

LEO launches are hard to multi manifest due to the wide range of incompatible inclinations.
GEO launches are easy to multi manifest from that stand point, but hard because of the higher performance required.
The problem Ariane V has with multi manifest is its payload to GTO limitations.
A bigger rocket with at least 20 tons to GTO will be able to regularly do triple manifests and sometimes even quad manifest launches.
A mini ITS rocket with expendable to LEO performance over 100 tons can likely to 15 to 20 tons to GSO using a bi elliptic transfer, or 20-25 tons to GTO-1500m/s, with full reuse.


A launch to 780km polar from Vandy isn't that much more than a launch to the ISS from the Cape, are you sure ? Not even 20% ?
SpaceX said they don't want to do ASDS landings. Of course that's aspirational/long term, but this thread is about longer term directions SpaceX will take, so we can't consider ASDS landings a good idea for ITS.


The payload impact on aircraft for reuse is much less than 5%.
The payload impact to fully recover rockets is likely to be over 50%, perhaps as high as 2/3 of payload capacity.
Ok, calling aircraft naturally reusable was a stretch from a rigorously natural view, but certainly from a mass penalty view it is.

[Lars-J]

But lets not ignore the fact that individual launches are a constraint on most ranges.
GEO/GTO missions are easy to multi manifest... If there's enough spare performance.

No, they are not easy. Arianespace does it, but only quite rarely, because they cannot find many satellites that can be dual-manifested.

LEO launches are hard to multi manifest due to the wide range of incompatible inclinations.
GEO launches are easy to multi manifest from that stand point, but hard because of the higher performance required.
The problem Ariane V has with multi manifest is its payload to GTO limitations.
A bigger rocket with at least 20 tons to GTO will be able to regularly do triple manifests and sometimes even quad manifest launches.
A mini ITS rocket with expendable to LEO performance over 100 tons can likely to 15 to 20 tons to GSO using a bi elliptic transfer, or 20-25 tons to GTO-1500m/s, with full reuse.

Why bother replying (and quoting) to someone when you completely ignore what they are writing? multi-manifesting, while "easy" in theory, are tricky to arrange. And you want to triple and quad manifest?