SpaceX: Mars Colonial Transporter "MCT" -- Speculation (not Raptor)

[sublimemarsupial]

Agreed, I always figured SpaceX would be building a whole system. That includes at least 3 legs, ... Earth-LEO, LEO-Mars Orbit and Mars Orbit-Surface and possibly more, if a cycler component is used (and for long term efficiency that seems the way to go to me). I'd call a cycler a spaceship

If I might go even further, I'd guess that as long as the physics work out, Elon will try and combine those legs into as few components as possible.

MCT is the whole vehicle which sits on the launch pad in Brownsville, TX. 12m+ diameter barrel for the whole thing - 3 first stage cores (FH style) powered by raptor engines and one combination 2nd stage + crew + cargo "spacecraft", big enough to house the colonists for the duration of the journey without the need for any "deployable" habs (Bieglow) or in orbit assembly. First stage cores are reusable, with two landing back at the pad and the third downrange. 2nd stage reaches orbit, does a quick checkout, and then does the TMI burn. At Mars, it aerobrakes and then executes a propulsive landing with its throttle-able raptor, using the last of its stored LCH4/LOX propellant. Colonists disembark and unload cargo, living in the spacecraft as a hab at first. Sabatier process to make LCH4/LOX for return journey, eventually the whole spacecraft launches from the surface back to mars orbit then does the TEI burn. Aerobrakes and executes a propulsive landing back in Brownsville, TX for cargo reloading, gets stacked with first stage cores, and flys right back to mars. Its direct throw taken to the extreme.

[Lar]

You can't be serious?

I thought it sounded good at first blush... but max reuse to my way of thinking means capsules for crew and payload shrouds for cargo to LEO.

From there out and back, reusability makes sense, and the capsules return to earth, sure, but the need for large downmass from LEO on return seems low. It will be a while before there is more cargo coming in than going out.

Landing the whole hab back on earth seems wrong.

[Lobo]

Agreed, I always figured SpaceX would be building a whole system. That includes at least 3 legs, ... Earth-LEO, LEO-Mars Orbit and Mars Orbit-Surface and possibly more, if a cycler component is used (and for long term efficiency that seems the way to go to me). I'd call a cycler a spaceship

If I might go even further, I'd guess that as long as the physics work out, Elon will try and combine those legs into as few components as possible.

MCT is the whole vehicle which sits on the launch pad in Brownsville, TX. 12m+ diameter barrel for the whole thing - 3 first stage cores (FH style) powered by raptor engines and one combination 2nd stage + crew + cargo "spacecraft", big enough to house the colonists for the duration of the journey without the need for any "deployable" habs (Bieglow) or in orbit assembly. First stage cores are reusable, with two landing back at the pad and the third downrange. 2nd stage reaches orbit, does a quick checkout, and then does the TMI burn. At Mars, it aerobrakes and then executes a propulsive landing with its throttle-able raptor, using the last of its stored LCH4/LOX propellant. Colonists disembark and unload cargo, living in the spacecraft as a hab at first. Sabatier process to make LCH4/LOX for return journey, eventually the whole spacecraft launches from the surface back to mars orbit then does the TEI burn. Aerobrakes and executes a propulsive landing back in Brownsville, TX for cargo reloading, gets stacked with first stage cores, and flys right back to mars. Its direct throw taken to the extreme.

Yea, MCT will probably be the general reference to Elon's whole planned architecture, like "Project Constellation" referred to Ares 1, Ares 5, Orion, and Altair.   
But I'd expect Elon to come up with a specific name for each element as it's developed (or if it's every developed).

The BFR will be the first element developed, obviously, so that'll probably get the first individual name.

As far as what the whole MCT architecture looks like?  Obviously that's the $1000 question, and why we're all blindly speculating on it.  :-)

We know or can reasonably guess a few things.

1)  There will be two different phases.  Phase 1 will be basic exploration, flags and foot prints, and testing of hardware and designs.  Especially if Elon beats NASA there, they will have to test a lot of things before any "regular" transportation can take place.  So the early missions might be very different that what he probably hopes to have later.

2)  Elon has a Red Dragon concept, so there's a reasonable chance the Dragon capsule will be used to get crews on the surface of Mars.  May only at first, with some different later maybe on during the "colonization" phase.

3) I think the initial exploration phase might look something like "Mars Semi-Direct".  There may be more expendable hardware during that phase to just make sure crews can get to Mars, and get home ok.  Later, that might start integrating some reusable hardware.  The launcher would be the first element to be reused.  And then maybe the Mars ascent vehicle.  If he can maybe a scaled up Dragon with Raptor engines that can fuel itself on the surface and with LH2 brought on subsequent missions, then it could possibly launch from the surface with enough propellant to get to orbit, and then descend like Red Dragon with a propulsive touchdown.  The big issue will be having Raptor engines that can fire into a supersonic airstream.  So that'll have to be worked on.  But I imagine if they can get the Superdracos to do it, then they could get a reusable Raptor engine.

On the Flip side, there might be a use for an expendable MAV lander.  It gets sent to Mars 2 years ahead of a mission to land using a heat shield, and then Raptor engines for touchdown.  It'll have a tank of LH2 and refuel itself on the surface before the crew gets there.  At the end of the surface mission, the crew gets in and lifts off for the MTV waiting in orbit.  The MAV lander will make enough fuel for lift off, as well as act as the Mars Departure Stage.  Once docked with the MTV, it'll perform TEI burn, and then be jettisoned.  That way the TEI propellant doesn't need to be brought from earth.  And as it's Methalox it'll be heavier than hydrolox.  However, if you are making it on the suface, then other than the LH2 feedstock, the methalox is "free".  The MAV just needs to be big enough and designed right.  So that might almost be better to do that try to design a reusable MAV.

4)  SpaceX will have invested a lot of time and money into Dragonrider and a man rated F9R.  I'm guessing the MCT LV will launch a hab and a MAV lander to Mars ahead of the mission per Mars Semi-direct, and then the MCT LV will launch a Marts Transit vehicle of some sort to LEO, and F9R will launch the crew on Dragon Rider for EOR.  They will take DRagon Rider to Mars with them, and then return to EArth in it on the way back.
A Red-DRagon will be part of the MTV stack, and the crew will descend to the Surface in it.

5)  I'd guess we'll see Bigelow modules play a role with  Project MCT.  The MTV for sure.  Perhaps the surface hab lander as well.  A BA-330 would make a pretty good hab for a crew of say four for the 6 months in each direction.  It'd launch fully provisioned for the crew with 6 months of supplies each way, and a big head shield.  Upon arrival at Mars, it can perform aerobraking maneuvers while the crew descends directly in Red DRagon (or the crew could descent after aerobraking/aerocapture is complete.) The heat shield can be jettisoned after, as it's not needed for the return trip.  Then once the MAV comes up from the surface, it docks, and then does the TEI burn, and then is jettisoned.
I think a Bigelow BA-330 or similar module would work good for that.  A smaller one could be used on the surface, sort of like the inflatable hab in Mars DRM 5.0, or Transhab. 

http://upload.wikimedia.org/wikipedia/commons/8/87/Transhab-cutaway.jpg

So, I'd sort of expect the initial exploration phase to be some sort of mixture of this...although obviously it could be anything, maybe something completely different.  But I think Elon would see the feasibility in Zubrin's concepts.

[Falcon H]

I love the idea of the MCT, but is Space-X biting off more than they can chew, almost definitely. Just look how much they have on their plate.

[FutureSpaceTourist]

I love the idea of the MCT, but is Space-X biting off more than they can chew, almost definitely. Just look how much they have on their plate.

You talk as if they're currently spending resources on this? I think it's probably years before SpaceX spend any signifcant time or money on it. As you say they're pretty busy at the moment!

[Dave G]

You talk as if they're currently spending resources on this? I think it's probably years before SpaceX spend any signifcant time or money on it. As you say they're pretty busy at the moment!

Commercial development flows like a pipeline: Concept -> Architecture -> Design -> Test -> More test -> etc.

Before something gets to production, the design engineers have usually moved onto something else.  In fact, if you don't keep your developers busy, they're generally not as happy, and more likely to move to another company.  Use it or lose it.

So yes, I believe SpaceX has already started some design work on MCT.  If a Merlin-1D or F9R issue pops up in test, they can put MCT on hold while they iron that out, and then resume after it's resolved.  This is fairly typical for commercial development.

[CapitalistOppressor]

You talk as if they're currently spending resources on this? I think it's probably years before SpaceX spend any signifcant time or money on it. As you say they're pretty busy at the moment!

Commercial development flows like a pipeline: Concept -> Architecture -> Design -> Test -> More test -> etc.

Before something gets to production, the design engineers have usually moved onto something else.  In fact, if you don't keep your developers busy, they're generally not as happy, and more likely to move to another company.  Use it or lose it.

So yes, I believe SpaceX has already started some design work on MCT.  If a Merlin-1D or F9R issue pops up in test, they can put MCT on hold while they iron that out, and then resume after it's resolved.  This is fairly typical for commercial development.

Exactly.  When our software developers release code they don't sit around twiddling their thumbs waiting on the next bug report.  They work on the next project.

With the M1D acceptance trials already completed, and the engine reportedly in production, I see little reason for the team which developed it to be spending much time on the M1D anymore.  If a bug develops they will address it, but I would find it very odd if they were not already spending the bulk of their time on the next project, which according to Elon is Raptor.

As to the MCT project as a whole, it's harder to say.  F9R is not in active service yet, but I doubt the designers are spending most of their time on it at this point.  Falcon Heavy on the other hand, is very much an active project, and should be the priority.  So the design team should be spending most of their time on that. 

But you always want to devote at least a little effort thinking about your next project, if only to get the basic architecture and planning in place to be able to efficiently transition your team as the current project winds down. 

And because the engines are at the core of the MCT project it doesn't hurt at all to have that team already off and running so that the vehicle design team has something concrete to design around.

[kiba]

Will there be a Merlin 1E?

[QuantumG]

Will there be a Merlin 1E?

Last I heard, no.. but who knows.

[Dave G]

With the M1D acceptance trials already completed, and the engine reportedly in production, I see little reason for the team which developed it to be spending much time on the M1D anymore.  If a bug develops they will address it, but I would find it very odd if they were not already spending the bulk of their time on the next project, which according to Elon is Raptor.

As to the MCT project as a whole, it's harder to say.  F9R is not in active service yet, but I doubt the designers are spending most of their time on it at this point.  Falcon Heavy on the other hand, is very much an active project, and should be the priority.  So the design team should be spending most of their time on that. 

Right.  Falcon Heavy is active, but it uses Merlin 1D, so the engine designers are probably already working on the next thing.

I'm not exactly sure what Raptor is these days.  First it was LH2/LOX second stage, but now it looks like Liquid Methane / LOX staged combustion, not limited to second stage.

So is Raptor the engine for MCT?  If so, then the engine designers would need some type of preliminary architecture to fit into.

[Lobo]

Right.  Falcon Heavy is active, but it uses Merlin 1D, so the engine designers are probably already working on the next thing.

I'm not exactly sure what Raptor is these days.  First it was LH2/LOX second stage, but now it looks like Liquid Methane / LOX staged combustion, not limited to second stage.

So is Raptor the engine for MCT?  If so, then the engine designers would need some type of preliminary architecture to fit into.

Yea, I'd be surprised if the "Raptor Development Team" at this point wasn't more than a small group that's fleshing out some of the prelimiary work to help hone in on maybe an optimum size based on what SpaceX thinks MCT will look like eventually (and that probably still in a lot of flux).
Once the engine guys get done with F9R and FH, they'll probably shift over to Raptor, and start design in earnest.  As Raptor currently looks like it might be a "family" of methalox engines, rather than just one, they'll have work ahead of them design a few different...but similar...engines.  Maybe seeing where the different variants can share common components with each other for maximum commonality, or perhaps some similar components with the Merlins. (if possible)

Vacuum and seal level versions, perhaps multi-chamber designs like the RD-170/180/190 family.  who knows.  be interesting to see what comes down the pipe.

[RocketmanUS]

Possible-

Raptor engine sea level 650,000lb thrust LHC4/LOX

Two stage HLV using Raptor sea level and 2nd stage vacuum rated engine.

Mars Transport System-

1 ) LEO supporting space station/depot
2 ) Tanker launched on HLV
3 ) Crew launched on F9/Dragon
4 ) Mars crew transport and lander launched on HLV, lands only on Mars and returns to LEO by aero capture for reuse and serviced by LEO station for next sortie to Mars ( cargo version too ).

So launch and assemble pieces of space station with depot so it can service the Mars transporter. Launch the Mars transporter to LEO station . Launch propellant tanker to station. Launch supplies with Big Sister Dragon on HLV. Dragon on Falcon 9 to bring crew to station ( up to six crew, pilot returns to Earth ).

Have all ready to depart when launch window opens. TMI burn and coast to Mars. When almost to Mars craft does course correction burn to help control were it will land. Enters mars atmosphere and uses it to slow down. Final velocity to landing change by it's engines for soft vertical landing. Once on Mars crew lives on craft till they assemble their habitat that was delivered by a cargo version of the Mars transporter.

When the time gets close for the craft to return to LEO it is refueled by Mars made LCH4/LOX. It does the burn to orbit and then the TEI burn. Uses aero capture to enter LEO. Possible cooling of heat shield with the fuel and or oxidizer throw channel walls in the crafts skin under the heat shield.

[Dave G]

Yea, I'd be surprised if the "Raptor Development Team" at this point wasn't more than a small group that's fleshing out some of the preliminary work ...

Once the engine guys get done with F9R and FH, they'll probably shift over to Raptor, and start design in earnest.

With the M1D acceptance trials already completed, and the engine reportedly in production, I see little reason for the team which developed it to be spending much time on the M1D anymore.  If a bug develops they will address it, but I would find it very odd if they were not already spending the bulk of their time on the next project, which according to Elon is Raptor.

My guess is closer to CapitalistOppressor.

[Dave G]

Possible-

Raptor engine sea level 650,000lb thrust LHC4/LOX

Two stage HLV using Raptor sea level and 2nd stage vacuum rated engine.

Mars Transport System-

1 ) LEO supporting space station/depot
2 ) Tanker launched on HLV
3 ) Crew launched on F9/Dragon
4 ) Mars crew transport and lander launched on HLV, lands only on Mars and returns to LEO by aero capture for reuse and serviced by LEO station for next sortie to Mars ( cargo version too ).

So launch and assemble pieces of space station with depot so it can service the Mars transporter. Launch the Mars transporter to LEO station . Launch propellant tanker to station. Launch supplies with Big Sister Dragon on HLV. Dragon on Falcon 9 to bring crew to station ( up to six crew, pilot returns to Earth ).

Have all ready to depart when launch window opens. TMI burn and coast to Mars. When almost to Mars craft does course correction burn to help control were it will land. Enters mars atmosphere and uses it to slow down. Final velocity to landing change by it's engines for soft vertical landing. Once on Mars crew lives on craft till they assemble their habitat that was delivered by a cargo version of the Mars transporter.

When the time gets close for the craft to return to LEO it is refueled by Mars made LCH4/LOX. It does the burn to orbit and then the TEI burn. Uses aero capture to enter LEO. Possible cooling of heat shield with the fuel and or oxidizer throw channel walls in the crafts skin under the heat shield.

Excellent post.

One question: Why would you need a station to service the transporter?  Could it be serviced by itself in LEO?

[JBF]

One question: Why would you need a station to service the transporter?  Could it be serviced by itself in LEO?

Depends on how fast you want to turn it around.  Pre-staging supplies in orbit will speed things up.

[RocketmanUS]

Possible-

Raptor engine sea level 650,000lb thrust LHC4/LOX

Two stage HLV using Raptor sea level and 2nd stage vacuum rated engine.

Mars Transport System-

1 ) LEO supporting space station/depot
2 ) Tanker launched on HLV
3 ) Crew launched on F9/Dragon
4 ) Mars crew transport and lander launched on HLV, lands only on Mars and returns to LEO by aero capture for reuse and serviced by LEO station for next sortie to Mars ( cargo version too ).

So launch and assemble pieces of space station with depot so it can service the Mars transporter. Launch the Mars transporter to LEO station . Launch propellant tanker to station. Launch supplies with Big Sister Dragon on HLV. Dragon on Falcon 9 to bring crew to station ( up to six crew, pilot returns to Earth ).

Have all ready to depart when launch window opens. TMI burn and coast to Mars. When almost to Mars craft does course correction burn to help control were it will land. Enters mars atmosphere and uses it to slow down. Final velocity to landing change by it's engines for soft vertical landing. Once on Mars crew lives on craft till they assemble their habitat that was delivered by a cargo version of the Mars transporter.

When the time gets close for the craft to return to LEO it is refueled by Mars made LCH4/LOX. It does the burn to orbit and then the TEI burn. Uses aero capture to enter LEO. Possible cooling of heat shield with the fuel and or oxidizer throw channel walls in the crafts skin under the heat shield.

Excellent post.

One question: Why would you need a station to service the transporter?  Could it be serviced by itself in LEO?

One question: Why would you need a station to service the transporter?  Could it be serviced by itself in LEO?

Depends on how fast you want to turn it around.  Pre-staging supplies in orbit will speed things up.

It's were the equipment is stored, EVA's take place.
Service crew and Mars crew stay on station.
Mars crew enters Mars transporter just before TMI burn.
Trash and waste is moved to station for future disposal.
Cargo versions can leave at other times with a longer transit time.
So the station would be kept busy. Can be used for other operations when not servicing Mars transporters.

For safety I see two of these crewed craft would most likely head to Mars together ( from t/Space CEV Lunar concept ).

[Falcon H]

Right.  Falcon Heavy is active, but it uses Merlin 1D, so the engine designers are probably already working on the next thing.

I'm not exactly sure what Raptor is these days.  First it was LH2/LOX second stage, but now it looks like Liquid Methane / LOX staged combustion, not limited to second stage.

So is Raptor the engine for MCT?  If so, then the engine designers would need some type of preliminary architecture to fit into.

Yea, I'd be surprised if the "Raptor Development Team" at this point wasn't more than a small group that's fleshing out some of the prelimiary work to help hone in on maybe an optimum size based on what SpaceX thinks MCT will look like eventually (and that probably still in a lot of flux).
Once the engine guys get done with F9R and FH, they'll probably shift over to Raptor, and start design in earnest.  As Raptor currently looks like it might be a "family" of methalox engines, rather than just one, they'll have work ahead of them design a few different...but similar...engines.  Maybe seeing where the different variants can share common components with each other for maximum commonality, or perhaps some similar components with the Merlins. (if possible)

Vacuum and seal level versions, perhaps multi-chamber designs like the RD-170/180/190 family.  who knows.  be interesting to see what comes down the pipe.

I have a L2 membership and check space news sites every day, yet this is the first I have heard of a methalox "family," I do recall reading an interview with elon where he said something about a new "family" of bigger rockets, but nothing about a "family" of engines. Would you mind showing where you found this? 

[Hyperion5]

Right.  Falcon Heavy is active, but it uses Merlin 1D, so the engine designers are probably already working on the next thing.

I'm not exactly sure what Raptor is these days.  First it was LH2/LOX second stage, but now it looks like Liquid Methane / LOX staged combustion, not limited to second stage.

So is Raptor the engine for MCT?  If so, then the engine designers would need some type of preliminary architecture to fit into.

Yea, I'd be surprised if the "Raptor Development Team" at this point wasn't more than a small group that's fleshing out some of the prelimiary work to help hone in on maybe an optimum size based on what SpaceX thinks MCT will look like eventually (and that probably still in a lot of flux).
Once the engine guys get done with F9R and FH, they'll probably shift over to Raptor, and start design in earnest.  As Raptor currently looks like it might be a "family" of methalox engines, rather than just one, they'll have work ahead of them design a few different...but similar...engines.  Maybe seeing where the different variants can share common components with each other for maximum commonality, or perhaps some similar components with the Merlins. (if possible)

Vacuum and seal level versions, perhaps multi-chamber designs like the RD-170/180/190 family.  who knows.  be interesting to see what comes down the pipe.

I have a L2 membership and check space news sites every day, yet this is the first I have heard of a methalox "family," I do recall reading an interview with elon where he said something about a new "family" of bigger rockets, but nothing about a "family" of engines. Would you mind showing where you found this? 

I tracked it down: http://www.flightglobal.com/blogs/hyperbola/2012/11/musk-goes-for-methane-burning.html

Big rockets need big engines which might also be used on Mars

The new Raptor upper stage engine is likely to be only the first engine in a series of lox/methane engines.  Larger engines will be derived from this.  For all his arguments noting the advantages of having lots of smaller engine for engine-out redundancy, it is known that Musk has long wanted to have a larger sized engine that the current Merlin 1.   Originally this larger engine dubbed Merlin 2 was to have been a generator cycle engine similar to the Merlin 1.  This has however now been dropped, again, in favour of a staged-combustion engine  using Lox/Methane as propellants.  The name of this new rocket engine which is expected to be in the 1.5 million lb thrust class has not been disclosed.

This is from Flightglobal, so it may not be accurate.  Based on what L2 members have been saying about the Raptor being a 650 klb/295 tf SC methalox engine, the article may also be out of date.  Lobo was noting earlier that if this engine were a quad-chamber design, it would not be too hard to create a single-chamber Merlin replacement from it (162.5 klb/ 73.7 tf is a near-match for the Merlin 1D (147 klb/66.67 tf).  That's part of the reason why some like to believe the entire Spacex lineup will eventually be switched over to burning methane & oxygen. 

[Lobo]

I have a L2 membership and check space news sites every day, yet this is the first I have heard of a methalox "family," I do recall reading an interview with elon where he said something about a new "family" of bigger rockets, but nothing about a "family" of engines. Would you mind showing where you found this? 

Well, nothing real definitive.  Which is why I say, " Raptor currently looks like it might be a "family" of methalox engines, rather than just one"

Extra emphasis on the "might".

http://en.wikipedia.org/wiki/Raptor_(rocket_engine)

"When first mentioned by SpaceX in 2009, the term "Raptor" was applied exclusively to an upper stage engine concept,[3] and 2012 pronouncements indicate that it still is a concept for an upper stage engine.[6] However, public information released in November 2012 indicates that SpaceX may have a family of Raptor-designated rocket engines in mind.[7]"

Note 7 there refers to this:

http://www.flightglobal.com/blogs/hyperbola/2012/11/musk-goes-for-methane-burning.html

"The new Raptor upper stage engine is likely to be only the first engine in a series of lox/methane engines.  Larger engines will be derived from this.  For all his arguments noting the advantages of having lots of smaller engine for engine-out redundancy, it is known that Musk has long wanted to have a larger sized engine that the current Merlin 1.   Originally this larger engine dubbed Merlin 2 was to have been a generator cycle engine similar to the Merlin 1.  This has however now been dropped, again, in favour of a staged-combustion engine  using Lox/Methane as propellants.  The name of this new rocket engine which is expected to be in the 1.5 million lb thrust class has not been disclosed. "

And just from a basic sense.  Merlin 1 and Merlin 1-Vac comprise the "Merlin Family" of engines  Although I could you could include the previous variants prior to the D in the "family", but I don't know if you can since they are out of production.  So the Merlin "family" only has two versions of the same engine in it.  And I could see that with Raptor.
Except, unless Elon plans to just scale up the F9 to an FXX class BFR, with 9 engines on the first stage, and a 1 single vacuum optimized engine on the upper stage, a design with fewer, larger engines means that a single really big methalox engine would likely be way too big to be the upper stage engine.  (think an F-1-Vac.  Unless staging is pretty early...which methalox probably won't be, it'd likely be a pretty oversized 2nd stage engine)  Which means there'd need to be a smaller version of the 1st stage engine optimized for vacuum. 

So, there's probably going to be a "family" of some sort with a new engine if Elon's going to go methalox for both booster and upper stage.

At some point, if Elon really wants to land on Mars, and get back off, there's probably need to be methalox engines optimized for that too, which could be variants of an upper stage engine, as they'll be operating in the near vacuum of the Mars atmosphere.  I'm assuming part of the change to methalox is it can be generated on the Martian surface.

So, in a loose sense, that's where I picked up on the "family" of Raptor engines. 

[Lobo]

Oops...Hyperion beat me to it.  :-)