WI: Falcon Heavy to Mars

[nixonshead]

In September 2016, Elon Musk unveiled his concept for an "Interplanetary Transport System", a fully reusable system for ferying people and equipment between Earth and Mars. This would go on to evolve into the "BFR" and later Starship/Super Heavy.

At that time, Falcon 9 had performed its first 1st stage landing the previous year, but Falcon Heavy was still a couple of years from flight. Crew Dragon was three years from its first uncrewed flight. A proposal to use an uncrewed Dragon capsule, launched on Falcon Heavy, to make a propulsive landing on Mars ("Red Dragon") was still under consideration.

But what if SpaceX had decided against the ITS/BFR/Starship approach, and instead chosen to use an architecture built around Falcon 9 and Falcon Heavy? Given the launch cadence now being demonstrated by Falcon 9, SpaceX can today deliver 1000+ tonnes per year to LEO, even without Falcon Heavy. Suppose the money and effort that IOTL went into Starship development had instead focussed on a mission profile using orbital assembly?

What would that look like?

Could we imagine a concept using Aldrin Cyclers shuttling between Earth and Mars, visited by Crew Dragon capsules boosted on Falcon Heavy? Perhaps taking advantage of Bigalow's bankruptcy to buy out inflatible habitat tech? How far might that have progressed by 2022? Would RedDragon still be a thing? Or a crewed Mars flyby, perhaps testing a Cycler?

How would that impact NASA's plans for the Moon? With no Starship, would SpaceX have bid for the HLS contract? Would they have won? Or would it be the National Team, with a bid twice as expensive? What would that mean for Artemis?

With a deep space habitat in development, would SpaceX leverage that to enter the emerging commercial space station market? (OTOH, there's no reason they couldn't do that with Starship).

I don't have answers, just a lot of questions that I'd be interested to hear others' opinions on.

 

[Polish Eagle]

I could see some kind of half-way system between FH and SS/SH. If you have FH, and if you want to land on Mars, you want a large-volume reusable upper stage anyway. So replacing the upper stage with a methane/oxygen "mini-Starship," as I think Zubrin has been plugging on and off, is the logical conclusion of that goal.

As to HLS, that would look very different. I think closer to what ULA proposed with ACES/DTAL. You start with an FH upper stage (or the notional methane replacement I suggest). Use that for most of the descent burn and then just some SuperDracos for the terminal descent. The upper stage can be returned to Gateway as an "un-crasher," as Jon Goff proposed many years ago.

With a 2016 initiation, I do think upper stage recovery would be in the testing phase by now. Propellant transfer is the other big thing to demonstrate--whether they'd spare an FH to demo that, I don't know.

 

[RanulfC]

The problem is you'd need to redesign the Falcon Heavy to really use it's payload capacity to the fullest and that means it's REALLY no longer compatible with the Falcon. (As is the core specifically and some of the newer side stages are not compatible nor can they be used as "Falcon 9's") The Falcon Heavy can't use a really good sized fairing (or upper stage) due to the fines ratio of the booster stage, the upper stage would end up too thin/skinny. (I'll try and find it as there's a good analysis of a possible "mini-Starship" for the Falcon Heavy that's NOT the one Zubrin keeps referring too. Some crude BOTE work shows a Raptor or BE-4 powered "Hercules" {scroll down} type vehicle could replace the Falcon Heavy upper stage and still deliver its full payload {21mt+} to orbit, but again I think it turns out to be too 'wide' for the FH stack)

The main issue with using the Falcon series is specifically the payload mass Musk zeroed in on (100mt to the surface per flight) and the fact he was adverse to any orbital assembly (or infrastructure) only reluctantly coming around to the idea of using a propellant depot because of the number of refueling flight required. You'd have to get Musk out of the Zubrin/Mars-Direct mindset and get him to accept a multi-layer approach.

Really the multi-launch and orbital assembly route would have made a lot more sense, though it would require additional expenditures that might not have played out as easily or cheaply as the "Starship" program. Frankly you need to have new space suits capable of actually working in space on a regular basis, orbital operations on a more regular basis and people stationed on-orbit to support the whole thing which entails someplace for them to live and work out of. It would be fairly 'easy' to upgrade the Falcon-9/Heavy with a more efficient propellant (liquid methane or even liquid propane ) to increase orbital payload but it's something that Musk has never been interested in following up. (Additionally or conversely the 'extra' performance could have also enabled upper stage recovery but...) Then there was the 'short-lived' partnership with Bigelow Aerospace to handle civil "flights" on the Falcon 9 to the ISS, which arguably could have been used to partner for a "Transhab" style orbital operations center and maybe a commercial space station. (Again no real interest from Musk) This would/could then lend itself to being expanded into an "Interplanetary Transfer Vehicle" like the "Spacecoach" (scroll down) concept which then transfers back and forth to Mars and other solar system destinations.

But again this all 'costs' in time/resources/money that can be argued that the 'cheap' nature of the on-going "Starship" program might not be similar. Frankly we've yet to see even a credible prototype 'Starship' design (crewed or cargo) and the Superheavy has yet to be flight tested at all so the relative costs so far have been facility and production which would also be required for a different F9/FH based program. Arguably you'd be much further along given the different goals, and personally I think the costs would have been much better spent but I'm not in charge

Randy

 

[RanulfC]

<snip>
What would that look like?

Could we imagine a concept using Aldrin Cyclers shuttling between Earth and Mars, visited by Crew Dragon capsules boosted on Falcon Heavy?

Cyclers have the issue that the needed Delta-V to reach them is pretty significant which would require a new upper-stage and/or tug for F9/FH but that's not a bad idea anyway. As I noted above I'm more a fan of propulsive transfer (Spacecoach ) myself.

Perhaps taking advantage of Bigalow's bankruptcy to buy out inflatable habitat tech?

SpaceX and Bigalow DID in fact partner up but Bigalow was mostly assigned to manage arrangements and services for SpaceX to fly passengers to the ISS. SpaceX was willing to support Bigalow if they paid to fly modules but they didn't fit Musk's plans so ...
(And frankly since the Bigalow designs are based on NASA work it's 'technically' mostly public domain-ish )

How far might that have progressed by 2022?

A lot depends on how the effort is organized and supported. Musk doesn't tend to really focus on the details, leaving that to 'others' and his support thereof tends to fluctuate pretty wildly. Assuming a more stable and well planned program, (not a description of the Starship/Superheavy program btw) and figuring starting around 2016 I'd have assumed we would have seen work begun on a more efficient upper stage using liquid methane and possibly a 'mini-raptor' (which the Air Force actually paid SpaceX to study but was set aside by SpaceX) followed by orbital propellant transfer testing and assembly testing. Considering this would not require going to the ISS it's possible we'd have seen a much earlier crewed Dragon flight, though I suspect that getting a working space suit would be the main driver for actual operations. By 2022 I'd think that SpaceX would have a working orbital propellant depot and have proved propellant transfer on-orbit along with a small 'operations station' where they were testing a lunar lander and the technology to build an ITV.

Would RedDragon still be a thing?

Red Dragon was never seriously studied by SpaceX as it was (rather correctly) seen as a 'side-track' since the Dragon capsule would actually have to have been extensively modified to work in that aspect. Given that the people that DID propose it could not find funding it's not likely it would have actually happened. But as I pointed out in a few threads over on NSF, there were Dragon 1 capsules "just" sitting around (used for ISS resupply but not reused due to then current NASA contract regulations) that could have been modified for use in several capacities if the funding could be found. I would like to think that in a run-up to actually trying to build and operate an ITV that SpaceX would have been more interested in the concept and seen it as a 'test-bed' project which perhaps would have included kicking in some funding and maybe 'donating' some equipment and work to such an endeavor.

Or a crewed Mars flyby, perhaps testing a Cycler?

The main issue is that flyby proposals have come and gone quite often but you don't really get any sustained enthusiasm for them. Hence the idea of testing a cycler with a crew is likely (pardon the pun) not going to fly. It's possible you could see a test proposed in Cis-Lunar space but heading out into deep space without a LOT of prior testing is frankly one of the reasons none of the credible people take Musk's "Mars Plans" (such as they are) seriously.

How would that impact NASA's plans for the Moon? With no Starship, would SpaceX have bid for the HLS contract? Would they have won? Or would it be the National Team, with a bid twice as expensive? What would that mean for Artemis?

Arguably in such circumstances the more realistic pricing that SpaceX would give would be balance by actual hardware and operations being 'proven' so that it's likely SpaceX would still 'win' but the price and timetable would be more realistic. NASA would still end up having to go back to Congress and ask them for an actual credible budget for the HLS but they'd have more 'proof' from the beginning that it might embarrass (it could happen ) Congress into offering a more credible budget in the first place.

With a deep space habitat in development, would SpaceX leverage that to enter the emerging commercial space station market? (OTOH, there's no reason they couldn't do that with Starship).

Well since we assume that SpaceX would have experience with orbital operations and assembly then it would make sense to parlay that into a 'commercial' station but keep in mind that the orbital operations center needed to support and service ITV's would likely not make a 'good' commercial space station specifically depending on "basis" of the commercial space station! Anything engaged in microgravity research is not going to appreciate the bumps and thumps of servicing and transfer operations whereas a space 'hotel' would interfere with those same operations and servicing. And keep in mind SpaceX isn't a 'servicing' or 'operations' company but a transportation company. (Hence a big reason they partnered with Bigalow for such activities for ISS passengers)
This btw applies to proposals for Starship as well; SpaceX isn't equipped or organized to do much OTHER than service a Starship to get it from one place to another. Someone else would have to do the 'work' of turning a Starship into a station. (Or anything else for that matter)

I don't have answers, just a lot of questions that I'd be interested to hear others' opinions on.

Don't we all and as you can see we've all got opinions as well

Randy

 

[RanulfC]

Found the post I was looking for:
Tough SF "SFR: Small Falcon Rocket" concept

SpaceX SFR: Small Falcon Rocket

A blog dedicated to helping Science Fiction authors create and discuss worlds where a realistic setting can still serve the fiction.

toughsf.blogspot.com

Randy

 

[nixonshead]

The problem is you'd need to redesign the Falcon Heavy to really use it's payload capacity to the fullest and that means it's REALLY no longer compatible with the Falcon. (As is the core specifically and some of the newer side stages are not compatible nor can they be used as "Falcon 9's") The Falcon Heavy can't use a really good sized fairing (or upper stage) due to the fines ratio of the booster stage, the upper stage would end up too thin/skinny. (I'll try and find it as there's a good analysis of a possible "mini-Starship" for the Falcon Heavy that's NOT the one Zubrin keeps referring too. Some crude BOTE work shows a Raptor or BE-4 powered "Hercules" {scroll down} type vehicle could replace the Falcon Heavy upper stage and still deliver its full payload {21mt+} to orbit, but again I think it turns out to be too 'wide' for the FH stack)

The main issue with using the Falcon series is specifically the payload mass Musk zeroed in on (100mt to the surface per flight) and the fact he was adverse to any orbital assembly (or infrastructure) only reluctantly coming around to the idea of using a propellant depot because of the number of refueling flight required. You'd have to get Musk out of the Zubrin/Mars-Direct mindset and get him to accept a multi-layer approach.
...

I'm not sure I see the need to redesign Falcon Heavy. With more frequent flights, you wouldn't need to repurpose cores as F9 boosters, just keep them in the FH fleet. The payload fairing issue could be problematic, but would the problem be significant enough to warrent developing an all-new stage and engine, with potentially new propellants?

I agree the fixation on 100t to Mars is the biggest driver away from a FH/F9 orbital assembly architecture. Not sure how you could plausibly change that - maybe distract Musk with Twitter or TicToc or something a few years earlier, or just a bump to the head that makes him decide on a more gradual approach? ;-)

 

[Joku_]

I'm not sure I see the need to redesign Falcon Heavy. With more frequent flights, you wouldn't need to repurpose cores as F9 boosters, just keep them in the FH fleet. The payload fairing issue could be problematic, but would the problem be significant enough to warrent developing an all-new stage and engine, with potentially new propellants?

I agree the fixation on 100t to Mars is the biggest driver away from a FH/F9 orbital assembly architecture. Not sure how you could plausibly change that - maybe distract Musk with Twitter or TicToc or something a few years earlier, or just a bump to the head that makes him decide on a more gradual approach? ;-)

On the other hand, if Musk and SpaceX get Starship to work in a reasonable timeframe, like orbital test in 2023 and commercial (non-manned) operation in 2024, the gamble will have paid off. After all, a Starship is a vastly superior launch platform when compared to a Falcon Heavy with bigger and better upper stage.

 

[RanulfC]

On the other hand, if Musk and SpaceX get Starship to work in a reasonable timeframe, like orbital test in 2023 and commercial (non-manned) operation in 2024, the gamble will have paid off. After all, a Starship is a vastly superior launch platform when compared to a Falcon Heavy with bigger and better upper stage.

Arguable given the supposed 'capabilities' versus the needed requirements of Starship let alone Superheavy. Falcon Heavy has a hard time finding payloads, (which this concept would actually fix) so something like Starship is going to struggle even more. Especially given the 'dodgy' economics and costs the system is supposed to have.

IF (and it's a big if ) SpaceX manages an orbital "test" of the Starship about the only thing they've proved is that they can toss an empty shell into orbit so they MIGHT be able to toss an expendable Lunar Starship into orbit sometime soon. If (again a big if) they manage to 'return' said empty shell it doesn't have the mass or flight dynamics of a 'real' Starship (even a 'cargo version') so not all that much 'progress' there. And all that's still not addressing the orbital refueling issues, payload bay issues, payload deployment issues... I can go on.

Falcon Heavy, (and the Falcon 9 family for that matter) are proven platforms with (somewhat, given how hard actual figures are to get out of SpaceX) proven economics that could have been used to do the things Musk says he wants to do, But he's unwilling to use those assets and he's unwilling to take the time and effort to improve them to the point where they could have been used or plan in such long terms.

Randy

 

[Joku_]

Arguable given the supposed 'capabilities' versus the needed requirements of Starship let alone Superheavy. Falcon Heavy has a hard time finding payloads, (which this concept would actually fix) so something like Starship is going to struggle even more. Especially given the 'dodgy' economics and costs the system is supposed to have.

On the other hand, apparently SpaceX has already developed extended fairing for the Falcon Heavy, which should fix the issue of payloads not fitting to the standard fairing. Of course, this won't bring any extra delta v that methane based second stage would, but still.

IF (and it's a big if ) SpaceX manages an orbital "test" of the Starship about the only thing they've proved is that they can toss an empty shell into orbit so they MIGHT be able to toss an expendable Lunar Starship into orbit sometime soon. If (again a big if) they manage to 'return' said empty shell it doesn't have the mass or flight dynamics of a 'real' Starship (even a 'cargo version') so not all that much 'progress' there. And all that's still not addressing the orbital refueling issues, payload bay issues, payload deployment issues... I can go on.

However, all of these other issues you mentioned would have been the same with a mini-Starhip launched with Falcon Heavy...

Falcon Heavy, (and the Falcon 9 family for that matter) are proven platforms with (somewhat, given how hard actual figures are to get out of SpaceX) proven economics that could have been used to do the things Musk says he wants to do, But he's unwilling to use those assets and he's unwilling to take the time and effort to improve them to the point where they could have been used or plan in such long terms.

Randy

Maybe Musk just thought that given lack of competition, the Falcon family is more than enough to service current customers, such as commercial satellite launchers and NASA's exploration programs. As such, he wanted to use the engineers he had on developing Starship rather than continuing to develop the Falcon family, which will become obsolete if Starship project succeeds.

 

[RanulfC]

I'm not sure I see the need to redesign Falcon Heavy.

"Need", probably not but Falcon Heavy isn't as efficient as it could be with the current design as it could carry much more payload than it does currently.

With more frequent flights, you wouldn't need to repurpose cores as F9 boosters, just keep them in the FH fleet.

True but as they are not really 'compatible' with the F9 fleet already it would make sense to modify the FH fleet to its fully capability for such a project. We're kind of assuming a similar level of effort/funding as towards Starship anyway so spending money to reach full capability would make sense. Of course that has issues in that the new core can't be shipped by truck and likely using 'standard' F9s would be problematic as boosters but if you have a new core then changing the boosters (standard F9) makes sense too. And you get a better F9 out of it also.

The payload fairing issue could be problematic, but would the problem be significant enough to warrent developing an all-new stage and engine, with potentially new propellants?

Methalox at some point was a given since they were planning on making methane on Mars. (Far from the only fuel that could be baselined but it was what Zubrin used so Musk used it) As such a new engine was going to happen and why not use it to improve the throw-weight of the upper stage? (Which also brings the possibility of designing and fielding a reusable upper stage making the FH/F9 a fully, or almost completely recoverable vehicle helping the economics even more)

As an aside I've played with the Silverbird calculator and the numbers for the "Hercules" lander concept (assumes that this would replace the FH second stage and fairing with the Hercules) using a single Raptor engine launched with a Falcon Heavy booster set and it gives me 26MT to LEO, which I'll note is 6MT more than the "Hercules" is designed to carry but that could translate to saving 6 metric tons of propellant The 'issue' is the "Hercules" is 6m in diameter while the current 'maximum' FH fairing is only 5.7m so ...
Reading here (scroll down to Hercules) it shows the same basic concept as Starship only with a more 'dedicated' set of vehicles with two (2) ITV's (Manned and Cargo) and one "Lander" design usable both for Mars, Luna, and 'technically" Earth (Some variation since the initial idea is not only to included crewed abort capability but to include some 'modular' designs that can rapidly build up a base and propellant depot infrastructure) I'd argue it's more 'realistic' in economy and payload but I know others have different opinions

I agree the fixation on 100t to Mars is the biggest driver away from a FH/F9 orbital assembly architecture. Not sure how you could plausibly change that - maybe distract Musk with Twitter or TicToc or something a few years earlier, or just a bump to the head that makes him decide on a more gradual approach? ;-)

Your biggest issue is Musk like things 'simple' (no matter how 'complicated' that eventually gets ) which was his attraction to Zubrin's "Mars Direct" planning in the first place. Second issue is orbital assembly IS more 'complicated' and takes planning outside of just 'shoot-it-directly-to-Mars-and-land' which is going to take some serious planning about the WHOLE mission architecture. Another thing that Musk does not like to do. Orbital refueling (likely with a dedicated depot, something that Musk is finally realizing Starship needs) orbital assembly, possible EVA requirements (which means space suit design, something that also applies to after-landing requirements) orbital coordination and assembly infrastructure, essentially all the things that Zubrin and by extension Musk don't want to deal with. (Because they both see it as "Battlestar Galactica" type bloated "government" ideas even though it's literally how MOST transportation systems operate) But all those elements are then available once in place for continued use and reuse which is hard to make clear when comparing to the 'simple' approach. (I mean even NASA in the form of Michael Griffin 'fell' for the Zubrin approach with the Ares V concept so I can see the draw)

So how do you get someone that loves 'simple' solutions to 'complex' problems to consider a more complex (and complete) solution?
Better advertising/propaganda? This was the issue with "Mars Direct" as it got a HUGE amount of public support and while it had some good points the bad (and there are many) got overlooked in rush. It got so popular that anyone who doesn't look closely thinks all the 'problems' are solved so of COURSE it's the 'easy' solution.

Education? Musk's not stupid, (he may be 'dumb' but he ain't stupid ) but nether is he the 'genius', super-smart-thinker' he and his fans like to think he is. The issues with his ideas have been brought up numerous time to him but he either ignore them or tosses off ill-thought-out or unrealistic 'solutions' and moves on. Getting him to face the actual issues and address them in a concise manner would help greatly but I suspect that would take a personality switch of the ASB type.

Distraction? Musk is always distracted but once he fixates on an idea he doesn't let it go even if it is a failure. He's got a knack of surrounding himself with people who can actually get jobs done and then getting rid of them once they start to try and point out flaws in his 'plans' and replacing them with people who are not as good but will agree with him. (SpaceX is a good example in fact) Musk is fixated on Mars, despite knowing how difficult and complex that will be but that predates even the foundation of SpaceX (his "Mars Greenhouse" plan) so I don't see how you can 'distract' him from glomming onto the Mars Direct/bigger booster concept.

Get SpaceX established and the Falcon-9/Falcon Heavy up and running and then have Musk run over by a runaway Tesla? Possible but really it's his 'drive' that is in fact driving Starship development even if it's not actually doing anything to get to Mars by addressing the REAL issues of getting there so removing him likely reduces the incentive. (Give the man some credit for being a 'hype' master even if his 'solutions' are more often wrong and than right and his 'hype' is far over the top most of the time, he knows how to 'sell' a brand) Maybe someone else (none of the current 'leadership' would seem to me to be capable) decides to 'dedicate' a Mars project to him posthumously?

The "100mt" to the surface of Mars is an absurd number to even start with, Zubrin never went above about 80mt for the very good reason that THAT was questionable with known EDL technology. (The original Hab was only about 30mt, the ERV about the same so where the idea of the need for "100mt" per flight came from....) Getting Musk to drop to some realistic numbers as I've noted would either take some VERY persuasive talking from someone he respects, (which itself maybe ASB ) or him actually taking the time and effort to study the actual issues and subject. (Let's face it, I would make an educated guess that you and I have about as much if not more 'knowledge' than Musk does on the subject and we've probably been 'studying' the issues longer than he has. Any chance he'd listen to us? None )

Still I'd like to sketch out some basics so can we just assume he MIGHT listen to someone and consider the concept?

Randy

 

[Orcbuster]

So why is this in alt history?

 

[1195]

A less ambitious Falcon based architecture may be more achievable than Starship but it's completely impractical for anything more than a small base.
Remember, Musk has been very vocal about his desire to colonise Mars, and Falcon Heavy just wont cut it, even with a better upper stage.

 

[RanulfC]

On the other hand, apparently SpaceX has already developed extended fairing for the Falcon Heavy, which should fix the issue of payloads not fitting to the standard fairing. Of course, this won't bring any extra delta v that methane based second stage would, but still.

"Extension" wasn't the actual problem, (it was/is for Starlink Gen2 but that's not the actual customer base) but a need to fit 'wider' payloads which runs into the fineness ratio issue. Customers wanted a wider (up to 9m in some cases but a full 6m would be more than welcome) fairing, not a longer one.

However, all of these other issues you mentioned would have been the same with a mini-Starhip launched with Falcon Heavy...

Given the rather random and unplanned nature of the "Starship" program you're probably right. That's NOT however inherent in the "program" it's indicative of a LACK of planning and or having an actual "development program". The false mantra of 'rapid iteration' really boils down to not having a credible design in the first place and throwing together ideas on the fly. My go-to here is the fact that they STILL don't have a credible landing gear design for the supposed 'reusable' Starship, arguably the FIRST thing they needed to design and build. This is NOT the way the designed and built the successful F9 and FH series and the difference shows in the 'quality' of the product.

We're 'assuming' a competent and thought out design and testing program with clear and realistic requirements rather than general concepts, and tossed out ideas. Don't get me wrong the folks at SpaceX have done some good work on getting 'something' flying but it's very much a VERY rough prototype with little utility without a LOT more work and money and it won't be quick and easy either.

Maybe Musk just thought that given lack of competition, the Falcon family is more than enough to service current customers, such as commercial satellite launchers and NASA's exploration programs. As such, he wanted to use the engineers he had on developing Starship rather than continuing to develop the Falcon family, which will become obsolete if Starship project succeeds.

Again it's a big "IF" and not a clear one at all. Yes Musk tossed aside the Falcon family for Starship but it's NOT because there's no competition, that's coming along in the background. (Specifically there's not clear 'economic' advantage to Falcon and it's not like the competition can't meet the current price point either) Musk is fixated on Starship so he's not interested in Falcon and while it's 'possible' that Starship would obsolete Falcon that's not at all clear since as I mentioned Starships payload and economics is all based on assumptions that are not supported by the figures we've seen. The 'assumption' is that Starship can fly essentially empty on any given flight and STILL be cheaper than Falcon and the simple economics of launch are not supporting that idea. The unrealistic assumptions on available payloads makes the numbers even worse. Musk is fixated on "Starship" in the context of Mars and everything else is secondary when a clear and easy "path" forward with F9/FH is available but ignored because of a 'requirement' Musk pulled out of nowhere.

But Musk is in charge of SpaceX so what he wants, he gets even if there is no economic or business reason for it. (See the "point-to-point" silliness) What we're looking at here is what if Musk were more realistic about going to Mars.

Randy

 

[RanulfC]

So why is this in alt history?

Because we're discussing a "What if Musk were really interested in going to Mars and planned accordingly?"

A less ambitious Falcon based architecture may be more achievable than Starship but it's completely impractical for anything more than a small base.
Remember, Musk has been very vocal about his desire to colonise Mars, and Falcon Heavy just wont cut it, even with a better upper stage.

And that fails right out of the gate because his Starship "plans" are not viable even if (and again it's a huge 'if') Starship works. Falcon Heavy and orbital refueling could easily put a lot of mass on Mars (and the Moon) and adding orbital assembly means even more payload over time. Something to remember is Musk has NO "plan" to actually colonize Mars nor has he invested in either the technology or infrastructure to do so even though that IS his stated goal.

You literally have to START with a base/outpost and even more importantly you have to invest in extensive exploration and surveying to even BEGIN planning a 'colony' and Musk is interested in doing NONE of that. Which is quite telling if you're paying attention. SpaceX is a transportation company and Musk is very much not planning on 'colonizing' Mars but he's expecting that someone else will use his transports to get there and doing all the real work. There is however a HUGE gap between what he envisions and what he's willing to do and IF he were actually serious he'd be doing the basic groundwork instead.

You can get around 20mt tons to orbit with a modified FH, put those together with a reusable ITV and you can ship hundreds of tonnes to Mars every window and couple all that with a reusable lander at Mars capable of transferring down between 5 and 20 tonnes a flight and you have the excellent start for everything from an outpost to a colony. there is no 'minimum' landed requirement, only 'nice to haves'. Requiring "100mt" in a single flight all the way from the surface of Earth to the surface of Mars limits your capability and requires a lot of expensive development and design. (Again something Musk is not doing at the moment) There are better ways of doing the job and FH is perfectly capable of doing the job as it is even without improvements.

But this isn't about what can do the job but what Musk wants. Again the difference between what he 'envisions' and what he's doing is huge.

Randy

 

[Joku_]

"Extension" wasn't the actual problem, (it was/is for Starlink Gen2 but that's not the actual customer base) but a need to fit 'wider' payloads which runs into the fineness ratio issue. Customers wanted a wider (up to 9m in some cases but a full 6m would be more than welcome) fairing, not a longer one.

Ok, although that sounds like it would have required a complete redesign of Falcon Heavy, which wouldn't have been a small feat either.

Also, does any current rocket even have a 6m or wider payload fairing? Apparently Ariane 5 has 5,4m fairing and Delta IV just 5m.

Given the rather random and unplanned nature of the "Starship" program you're probably right. That's NOT however inherent in the "program" it's indicative of a LACK of planning and or having an actual "development program". The false mantra of 'rapid iteration' really boils down to not having a credible design in the first place and throwing together ideas on the fly. My go-to here is the fact that they STILL don't have a credible landing gear design for the supposed 'reusable' Starship, arguably the FIRST thing they needed to design and build. This is NOT the way the designed and built the successful F9 and FH series and the difference shows in the 'quality' of the product.

We're 'assuming' a competent and thought out design and testing program with clear and realistic requirements rather than general concepts, and tossed out ideas. Don't get me wrong the folks at SpaceX have done some good work on getting 'something' flying but it's very much a VERY rough prototype with little utility without a LOT more work and money and it won't be quick and easy either.

On the other hand, it can often be faster to prototype rather than make specs for everything and then design it all on the drawing board. AFAIK the Soviets used somewhat similar approach in their early space program, which was quite successful considering their budget when compared to the Americans.

For example, STS had a completely different approach, where everything has definite specs before anything at all is built, and it has been hugely behind schedule and over the budget. Granted, it has had other issues like the legacy hardware imposed by the US Congress, but still...

Again it's a big "IF" and not a clear one at all. Yes Musk tossed aside the Falcon family for Starship but it's NOT because there's no competition, that's coming along in the background. (Specifically there's not clear 'economic' advantage to Falcon and it's not like the competition can't meet the current price point either) Musk is fixated on Starship so he's not interested in Falcon and while it's 'possible' that Starship would obsolete Falcon that's not at all clear since as I mentioned Starships payload and economics is all based on assumptions that are not supported by the figures we've seen. The 'assumption' is that Starship can fly essentially empty on any given flight and STILL be cheaper than Falcon and the simple economics of launch are not supporting that idea. The unrealistic assumptions on available payloads makes the numbers even worse. Musk is fixated on "Starship" in the context of Mars and everything else is secondary when a clear and easy "path" forward with F9/FH is available but ignored because of a 'requirement' Musk pulled out of nowhere.

But Musk is in charge of SpaceX so what he wants, he gets even if there is no economic or business reason for it. (See the "point-to-point" silliness) What we're looking at here is what if Musk were more realistic about going to Mars.

Randy

Do you mean that there's no business case for Starship with CURRENT payloads, that are designed to minimize size and weight? From purely monetary perspective, that is probably true. But if Starship is going to succeed, it's going to change the game in a big way, which is probably what Musk wants.

But why do you think that SpaceX's competition could match their prices, when they don't have reusable rockets yet? Apparently first stage costs around 70% of the rocket, so that's a pretty big saving, especially as they have been focusing on actually making the refurbishment process less costly.

Further, if Starship succeeds and makes the second stage reusable as well, that's going to further reduce the costs. Even if the refurbishment costs go up due to the vehicle being much larger, not having to make a new second stage should still make Starship cheaper to fly than Falcon 9.

 

[RanulfC]

Ok, although that sounds like it would have required a complete redesign of Falcon Heavy, which wouldn't have been a small feat either.

IIRC SpaceX thought at one point they could both extend and widen the fairing (up to 7m) but it turned out they can't really get much wider than 5.7 which would be 'workable' (They hope )

Also, does any current rocket even have a 6m or wider payload fairing? Apparently Ariane 5 has 5,4m fairing and Delta IV just 5m.

Studies have been done that show the Ariane can probably take a 6m fairing, maybe 7m (like SpaceX 'they hope' ) where as SLS is working up to a 9m fairing as a possible option. That's kind of the 'problem' that there is a customer 'need' for wider fairings but nobody wants to try 'build it and they will come' because they usually don't.

On the other hand, it can often be faster to prototype rather than make specs for everything and then design it all on the drawing board. AFAIK the Soviets used somewhat similar approach in their early space program, which was quite successful considering their budget when compared to the Americans.

When the Soviets tried prototyping over testing they tended to fail, hard. Examples would be the Proton and N1. The Americans tended to test more and succeed more even though they got off to a rocky start. Examples would be Saturn 1 and Saturn V. Nobody 'designs' rockets (or other transport systems) like SpaceX is doing with Starship for a good reason. Keep in mind that SpaceX has yet to have a 'successful' (one that can be reused) landing. (The aforementioned landing gear issue and things like constant engine 'bay' fires because there's a very good reason launch vehicles don't have recessed engine bays)

For example, STS had a completely different approach, where everything has definite specs before anything at all is built, and it has been hugely behind schedule and over the budget. Granted, it has had other issues like the legacy hardware imposed by the US Congress, but still...

And budget issues and schedule issues to name a few others. SpaceX used pretty much the same process to design and build the Falcon series, and it's because that systems works whereas the "rapid prototyping" is not that they did so. Don't get me wrong, rapid prototyping and rapid iteration has it's place but you HAVE to have a decent basic design to start from. Starship currently can't do ANY of the things it is supposed to be designed to do.

Do you mean that there's no business case for Starship with CURRENT payloads, that are designed to minimize size and weight? From purely monetary perspective, that is probably true. But if Starship is going to succeed, it's going to change the game in a big way, which is probably what Musk wants.

A lot of 'ifs' and yes it's what Musk "wants" but it's been clearly shown there is a huge difference between the things Musk want's and reality. Specifically the market is BASED on current payloads and it takes a lot of time, money and effort to change that which means Starship as designed is looking to LOSE money while waiting for the market to catch up, if it even does. (Another problem is that there has to be both interest and incentive TO change and the entire "space" market is notoriously static and conservative) Musk's entire 'strategy' is based on the assumption that payloads and customers will appear once the capability exists but that's not how the markets work, Fundamental change is often slow and steady not fast and fluid. The other issue is Starships size itself will make it expensive both to use and operate and while reuse can reduce some of those costs a LOT of the major upfront costs get more expensive with bigger size.

Yes Musk WANTS Starship to be a 'game-changer' and is making assumptions and promises based on that desire but the reality isn't so clear nor is it matching those desires.

But why do you think that SpaceX's competition could match their prices, when they don't have reusable rockets yet? Apparently first stage costs around 70% of the rocket, so that's a pretty big saving, especially as they have been focusing on actually making the refurbishment process less costly.

Because the actual launch prices have not dropped as significantly as was promised by Musk, and more specifically the regular vendors are still selling all the flights they can handle. SpaceX has the highest flight rate but only because they are paying themselves to launch Starlink's. The launch market is still pretty low and at this flight rate expendable and reusable still pretty close in overall costs. Reuse has not as of yet made enough of a difference that it's clear it's a better option. The competition isn't dumb here and they realize that reuse is likely the future but unlike SpaceX they would have to invest quite a bit in changing that at this point still is not clear that such an investment is called for. Also keep in mind that the competition has a depth and pockets that are deeper and wider than SpaceX's so WHEN they choose to make the change they can likely do so faster and more effectively than SpaceX did even starting from what looks to be an inferior position. (It pays to remember that these companies have decades of legacy studies and works on reusable concepts to choose from)

Further, if Starship succeeds and makes the second stage reusable as well, that's going to further reduce the costs. Even if the refurbishment costs go up due to the vehicle being much larger, not having to make a new second stage should still make Starship cheaper to fly than Falcon 9.

Eh, that's already wrong because the Falcon 9/Heavy second stage is a fully operational vehicle whereas Starship is very much not nor anywhere near such. And because it's bigger it will cost more to outfit and maintain. (And keep in mind the whole "reusable from the start" mantra is not true from the get go, they still have yet to show reuse at all) And again that's a lot of 'ifs' being thrown around with little to back it up. Bigger vehicle always cost more to use and maintain, launch costs are going to be higher and again even if it costs the 'same' as the Falcon 9/Falcon Heavy that means it won't work as advertised or be as effective.

Now it's a non-zero chance that Musk is actually right, (he's more often wrong than right keep in mind) and Starship does end up being all he claims it will be and more but the actual odds are very much against that.

What we're looking at here is the "what if" of Musk only having the Falcon family to work with and the outcome of that train of logic. Starship is a neat concept but as of yet it's not proven ANY of the claims made for it so I'm inclined to doubt those claims. YMMV

Randy

 

[RanulfC]

So:

What do we have to work with:
A Falcon Heavy can deliver about 64mt to LEO, a Falcon 9 puts about 23mt (expendable) or 15mt (reusable) into LEO. (For reference in reverse order that's one to three "empty" Hercules type vehicles assuming the ITV version has about the same dry-mass as the lander, likely less, but go with it for the moment) We also have the Dragon capsule, (we'll assume Dragon 2 standards) which can carry 4 to 7 crew and some cargo. Kerolox is a non-starter for deep space use but 'might' allow going to the Moon but lets just say that Musk will likely stick with methalox for the Moon and Mars. We're not going to worry about landing on Earth as we have Dragon for that so we'll 'assume' an ITV/lander design that can be used at either the Moon or Mars. (Another aside but Hercules was designed with this criteria but found to be 'possible' to land it on Earth with enough work so I'm going to use it as a baseline)

First things first as we're 'stuck' with the Falcon architecture (again not at all a 'bad' thing) then we'll have to assume orbital assembly and orbital propellant transfer from the start and plan accordingly. Since it's a major milestone then we need to demonstrate and develop it right off the bat using what we have. Design and built a demonstrator using a Falcon 9 likely using a modified upper stage and payload assembly to transfer LOX from and back into the LOX tank and LNG into the (vented and resealed) RP1 tank. Do this several times and if possible include a demonstration cryo-cooler system to keep the propellants liquid. (As per OTL NASA will likely pay for this)

Next is the design and construction of a methalox engine, we'll assume Raptor even though it's a bit overkill for the task and has no real use outside the architecture. (Can't be used for a new upper stage per-se without major redesign of the Falcon series. Note the Air Force will still likely put up some money for a study on a 'mini-Raptor' and I'd take them up on it but we'll assume Musk still declines the effort and says it's not workable) While that is ongoing we actually design and develop a workable FH launched ITV and lander design. If we're lucky we can do so to utilize the same basic mold lines but internally fitted to optimize for the task at hand. Planning for aerobraking at Mars means that most of the designs could utilize most of the same parts whereas a Lunar version can be optimized for no heat shield and more propellant. (Here was can then bid this for the HLS competition though we're likely going to have harder figures to work with if need be we can still low-ball the costs and likely win)

Meanwhile we need to tie heavily into ongoing, planned and proposed pre-cursor missions which is where 'donating' a used NASA Dragon and supporting "Red Dragon" would be a good idea, but more than that we need to actually dig into serious plans for Mars EDL, outpost design and construction and Lunar exploration plans. Further if we can start using on-orbit propellant transfer in 'operational' use that would be great but that would probably mean heavy redesign of the Falcon upper stage, though we could work out an on-orbit 'tug' demonstrator that can be re-fueled on-orbit which would boost a lot of areas. Likely Starlink still happens which will give some satellite and communications background work but also take up a lot of F9 flights. (Note that that's about the ONLY other company that Musk owns that 'helps' at all here. Tesla battery technology is literally just standard lithium ion power cells and Solar City is standard solar arrays and installation thereof, no help for the Moon or Mars)

By now we have a credible concept for the lander (and actual landing gear ) so we'll aim for the Lunar version first but test a 'boiler-plate' VTVL design (essentially current Starship but smaller) for landing tests with an eye towards future Mars landings. (No belly-flop, just straight up and down to simulate a Lunar landing vehicle, aiming for a vehicle dry mass of around 20mt) Should have the available by the time Artemis 1 launches TTL. Also should be able to field a basic "ITV" version capable of going to the Moon and back to LEO and show basic propellant transfer and orbital maneuvers. (And here things get sticky because we're essentially 'upstaging' NASA but...) Giving us the ability to do a "Dear Moon" flight demonstration.

Essentially we have everything in place to begin trying out some of the Lunar and Mars architecture and at this point we'd invite participation from interested parties to help develop the needed infrastructure but we have to be careful again because this puts us in competition with our main money source, NASA Given the leg-up with using the legacy Falcon family for launch I'd be highly surprised if we're not at this point before 2022 but we'll say we may drag our feet a bit to ensure NASA gets enough credit.

Thoughts?

Randy

 

[RanulfC]

No replies?

In a funny bit of synergy it turns out the listed "Abort/Terminal Landing Engines" for the Hercules are estimated to require 60kN/13,500lf each (with a total of eight) which matches the SuperDraco thrusters at 71kN/16,000lbf. Considering a need for more propellant to meet the landing requirements I can see this as being pretty straight forward.

General question to the aerospace experts on here: One 'nice-to-have' feature I'd like to see is moving the payload bay downward towards the top of the engine thrust structure to allow easier loading and unloading of the vehicle on Luna or Mars. I "think" it could work but am not sure, anyone want to weigh in on the idea?

As an aside:

I'd give credit to the artist but I can't get the nasaspaceflightdotcom threat "Buidling a Better Shuttle" to open. It's a concept called the "Stanley Shuttle" and don't be fooled that's not a Falcon Heavy (though the artist does like SpaceX a lot ) given the 'shuttle' is actually about the size of an standard Orbiter but it gives an idea. (And yes the artist is now aware that putting the cargo door on the windward side of the vehicle is a 'bad' idea )

Randy

 

[marathag]

No replies?

In a funny bit of synergy it turns out the listed "Abort/Terminal Landing Engines" for the Hercules are estimated to require 60kN/13,500lf each (with a total of eight) which matches the SuperDraco thrusters at 71kN/16,000lbf. Considering a need for more propellant to meet the landing requirements I can see this as being pretty straight forward.

General question to the aerospace experts on here: One 'nice-to-have' feature I'd like to see is moving the payload bay downward towards the top of the engine thrust structure to allow easier loading and unloading of the vehicle on Luna or Mars. I "think" it could work but am not sure, anyone want to weigh in on the idea?

As an aside:
View attachment 800475
I'd give credit to the artist but I can't get the nasaspaceflightdotcom threat "Buidling a Better Shuttle" to open. It's a concept called the "Stanley Shuttle" and don't be fooled that's not a Falcon Heavy (though the artist does like SpaceX a lot ) given the 'shuttle' is actually about the size of an standard Orbiter but it gives an idea. (And yes the artist is now aware that putting the cargo door on the windward side of the vehicle is a 'bad' idea )

Randy

Or somebody watched too much '80s TV

https://friday87central.files.wordpress.com/2010/05/vulture1.jpg

 

[RanulfC]

Or somebody watched too much '80s TV

https://friday87central.files.wordpress.com/2010/05/vulture1.jpg

Well to be fair TV's had some influence yes "Enhance American Gear for Lunar Exploration/Exploitation" or EAGLE comes to mind

(Alternate Lunar Lander program for CEV proposal. See: "CIRA/AAS EAGLE" concept here: http://www.projectrho.com/public_html/rocket/excursion.php)

This was part of the concept for "Project Moonlight" and included a common pressurized volume and "Advanced Reusable Italian Expandable System" or ARIES

Randy