…and its uninspirational end:
…as this latest episode demonstrates, unaffordable programs like the SLS are not a highway to the solar system. They are a roadblock.
Another mission destroyed by the big-rocket myth.
4 thoughts on “Inspiration Mars”
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The monster rocket advocates remind me of the stimulus advocates. No matter how big it is, no matter how many times it’s found to be unsustainable, their only response is “More! Bigger!! Even More Bigger!!!”
You don’t need two FH flights either. The dragon with an inflatable, supplies and crew could go on a single F9. This forces you to keep the mass down. The upper stage is retained. Then a single FH refuels it for the voyage. I’m told CJ is working on the numbers and will have a post about it shortly.
Somebody like ILC Dover would have to design the inflatable but it should be simple since the dragon will have the life support for it. They need about 2 or 3 m3 of supplies which could easily go up with the crew. They don’t inflate until they are on their way. The whole mission is about $250m.
I strongly recommend the linked article. Excellent.
One thing though; If I’m remembering correctly, Tito’s SLS-based new proposal does not use an Orion, but rather an “Orion-derived vehicle.” . Based on the open conical shroud surrounding the capsule in the artwork (What the heck is the purpose of that?) it looks to me like a smaller version or Orion. In other words, a vehicle that does not even exist on paper yet, so even more unlikely than an actual Orion.
As Ken mentioned, I’m trying to come up with a theoretical Mars flyby mission plan that could be done with existing launchers and hardware (except for the life support system). It could be done easily with 1 F9 and one FH, but I’m trying to avoid using FH in the concept due to the “Existing” criteria.
The biggest mass issue is fuel – you need a lot to boost from Leo to the Mars trajectory (3.4kps). So, amongst other things, I’m trying to reduce the needed Delta/v, but so far I’ve only got it down to to 2.9kps, and for that, we’d need a storable stage capable of at least a few hundred meters per second to do a second burn at pericynthion. I still need to find actual ISP numbers for the PAM-D solid stage, but it might work. I’m also playing around with using something other than LEO as a better fit for an initial orbit to better fit the available capacity for in-space stages to do the TMI burns.
I’m having a heck of a time finding stage specs. I know how to do wetmass/dry mass calcs (assuming the ISP is available) to work out delta/v figures, but data like that was hard to find, and I can’t find it for PAM-D. (Which is a solid, but the same principles apply). All I have so far is some specs from the 1980’s saying it can boost a 2750lb spacecraft from LEO to GTO, and I can derive the numbers from that, but… I don’t know if those specs are still accurate.
A stretched Centaur would be ideal (But you’d need to use a FH to launch it… nothing currently flying could launch an even slightly stretched fueled Centaur, and nothing but a Delta-4 HEavy could lift a fully fueled standard one without using it for a burn to reach LEO) so I’m trying to figure out a way to reduce the needed delta/v from the assembly orbit (which need not be LEO – it could be a higher energy orbit if that’s a better fit, and that reduces the TMI delta/v in itself).
I’m just doing this for fun and to relearn some math skills, but my goal is to see what I can come up with using existing hardware in the main, and as a side goal keep the price under what Inspiration Mars initially proposed. It will need in-orbit assembly, but the assembly will be limited to docking.
Dragon will be part of it.. as will the Falcon 9 1.1. I know the manned Dragon does not yet exist, but the cargo version has flown, so I’m counting that as existing. And, though the LAS might not be available, I’ll note that Shuttle didn’t have one either, and Shuttle wasn’t actually “Man-rated” in NASA’s own parlance.
As for heavy lift… I totally agree about SLS being a roadblock. I have nothing against heavy-lift per se, but I only favor heavy lift when it reduces the price per pound to LEO. In other words, if you had a heavy lifter that could fly a payload at $500 a pound, I’d be all for it. I’m in favor of Falcon Heavy (which incidentally will have a similar payload mass to SLS Block 1) because it has a low price per pound. But SLS is the opposite; it’s far too expensive to be useful for anything.
I would like to note that if a depot existed I would only be talking about one F9 launch for I.M. to happen.
Infrastructure changes everything.