The more I look at the concept I’m evolving as Mars Ultra-Direct, the more I like it; indeed, I’m increasingly beginning to conclude that I’ll probably end up writing a book on this very topic at some point in the not-too-distant future, probably as a companion to the projected novel I’m supposedly working on. (I’m getting obsessed with the research, I freely admit, and there’s absolutely nothing wrong with that.) I actually think I’m coming up with a workable mission profile, an architecture that actually could put Man on Mars at relatively low cost.
One element that had been worrying me was the size of my projected Mars Transit Vehicle. I’m currently working on something of a similar size and weight of the cancelled Sundancer module (hell, if NASA offered to pay for it, I’m sure Bigelow Aerospace would be only too happy to drag it out of mothballs) which has a usable living space about 50% larger than the ISS Destiny module. There would be the Dragon lander, of course – which would still be usable as living space – and a pair of BEAM-descended additions for logistic storage. That gives maybe 200 square meters of living space for four people. Doesn’t sound like much, does it?
The Russians might disagree. That’s twice as much as a Salyut station, and they were nominally designed for a three-man crew. And, oddly enough, so would NASA, much to my surprise. I’ve been looking at their ‘Deep Space Habitat’ concept, which uses as its crew accommodations for a 500-day four-man flight...a Destiny module and an MPLM. I think I’ve actually come up with a MTV with significantly better capacity than NASA, at a vastly reduced cost – and one that can be launched on a single Falcon Heavy into Martian Transfer Orbit.
Having said that, I wouldn’t go all the way from the surface of Earth. Better, as I’ve said before, to get into LEO and perform a series of checks first, spend a month or so to ensure everything is working before departure. I’d launch the crew separately as well, which adds another advantage – they can bring their consumables with them. On the assumption that they will launch in a normal Dragon Two, carrying only four men rather than seven, they’ll be able to bring the food and water they’ll need for the flight to Mars with them when they launch from Earth – which is three tons that the Dragon Heavy won’t need to bring up in the initial ascent. Just a nice little extra ‘gimme’.
I’m pretty sure – though to be fair, it is tight – that this mission would work with hardware that should be available by 2020; by 2030, I suspect things will have improved considerably. The first versions of the Falcon 9, for example, had only about half the capacity of the most recent iteration. It seems reasonable to conclude that, after a decade of flight, similar improvements will have been made to the Falcom Heavy design, and that the Falcon Heavy 2 (or even 3) will be able to put 20-25,000 kg on trajectory to Mars. Failing that, there remains the option of on-orbit refuelling prior to departure, either with a second Falcon Heavy or even a Falcon 9. (Again, improvements to this model are likely – assuming falling costs haven’t led to the retirement of the Falcon 9 completely in preference to its larger brother.)
As crazy as this seems, I’m beginning to think that this could actually work – the key remains reducing the amount of mass you have to take to the surface of Mars, and the concept of going directly to a fixed surface station, rather than a constantly-expanding base. It’s hard to get past three Falcon Heavy launches for that, I confess, though the larger the surface payload, the better scientific payoff you get for the base – going to 12,000 kg, for example, means a base half again as large, potentially a second buggy or a lot more first-mission logistic support, and a more capable reactor/refinery combination. (Potentially, that could carry other equipment as well – drones, for example, though I would recommend a capacity for additional storage. Perhaps it could house a backup communications system, or something along those lines – the more mass, bluntly, the better.)
There is potential, of course, for the MTV to be larger on the way home than it was for the journey to Mars. I’ve established that there are two Falcon Heavy flights in each launch window – one carrying the crew, the other carrying two logistic modules, one for the surface, one for orbit. There’s nothing to stop the orbital logistic module being pressurized – in which case, it can take the place of the then-redundant lander at the front of the MTV, potentially providing half again as much living area. (Bonus points if that module includes equipment to analyze the samples and data brought up from the surface – they won’t need access to that on the way out, but they will on the way home.)
Fourteen Falcon Heavy flights, then – even unmodified, it ought to be possible. And fills the requirement of being able to complete this project quickly. With a green light by a new President in, say, 2021, it would probably be possible to get the first MTV into a launch window in 2027, to land near the end of that year. And to those who think it cannot be done, I note that this is roughly the same sort of timeframe as Project Apollo.
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