Quote from: neveroddoreven on 07/22/2013 06:29 am... but I would think that LOX would be a bigger concern ...Mars has plenty of easily-processed Oxygen, in the convenient form of Co2 gas. All that is needed to make LOX is some plumbing and a heap of energy.Making methane is very much more difficult. The problem being sourcing hydrogen. There simply isnt enough of it in the atmosphere, in any form, to use as feedstock for fuel-making. One would need to either import the H2 (all the way from earth!!!), or mine it as water-ice from the surface.Mining is *much* more complicated than simply using the atmospheric gasses.
... but I would think that LOX would be a bigger concern ...
If you produce Methane from local water and CO2 you produce the correct amount of O2 in the same process as byproduct out of the water and CO2 used. So no separate production required.If you want to produce O2 for breathing in the habitat, it is easiest to split CO2 into CO and O. That process requires the least energy input. That be the easiest process too, if you want to produce storable fuel, 2CO and O2 to burn to produce heat and electricity at night.
Guys. You need to get this back on to the thread title, or I'll have to trim the thread.
I don't think that a minimalistic transport architecture (in its very first iteration) means that the base has to have somehow low ambitions, or consist of people sitting in tin cans. I just think that the most reasonable is to get something working that has the potential of evolving into something sustainable.
Elon already said at some some Q&A at a college a few years ago, it's on youtube, that he wants to be able to land 50 tonne infrastructure elements. That implies a downmass of more (descent propellant, engines, structures, etc.), in order to get a 50 tonne piece down. It's a debate for a different thread whether the undivisible 50 tonnes is a "base in a box", a drilling rig, nuclear back-up, bull-dozers, dump trucks, solar farm, rail ties, smelter/foundry elements, wire, or power broadcaster's, a case of Tesla's, or what-have you. It looks like there is sufficient interest to start one. I think it's reasonable to do so within the SpaceX section of this forum, as it is their stated goal, and we know the SpaceX specific 'landing 50 tonne indivisible elements to the surface' constraint. We also know the goal for methane MCT is tens of thousands of people. Work from that, otherwise the thread will go all over the place.
Tinker's dialog with Musk on MCT is important. It shows that we can take in-space assembly, Mars-orbit, and exotic propulsion off the table. For manned, it's probably as simple as launch, fuel, go, land, ISRU, fly back.
I've got reason to believe that Musk likes solar electric propulsion for his Mars mission concept.
Anybody ever thought that they might be considering some sort of Mars Cycler system similar to what has been suggested in the past?
Quote from: Robotbeat on 07/22/2013 08:06 pmI've got reason to believe that Musk likes solar electric propulsion for his Mars mission concept.Extraordinary claims require extraordinary evidence?
NASA has been fretting over how to land a payload bigger than 1 ton (Curiosity-class) on Mars. The Russians also. I think the assumptions are that 1) there will be too little fuel available to do a fully propulsive landing, 2) you can't make or launch a heat shield big enough to dissipate the energy to slow enough for parachutes, 3) you can't make hypersonic parachutes that will work for a Mars descent.So what is the secret that will allow a 50 ton MCT to land, which NASA doesn't know about?