In situ propellant production
In situ propellant production
(OP)
Can anyone help with information on a system I remember hearing about a while ago? I think it was called "ACER", but I'm unsure. It takes in oxygen while in flight and somehow converts it to liquid, stores it, then uses it for fuel.
Any information would be greatly appreciated. Thanks in advance.
Any information would be greatly appreciated. Thanks in advance.





RE: In situ propellant production
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Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: In situ propellant production
RE: In situ propellant production
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: In situ propellant production
RE: In situ propellant production
I only bring this up because ISPP research seems to have reached a brick wall in terms of its requirement that the sorbent bed, sorbent cooler, pump, storage of CO2 is so dependent on nighttime and daytime and thermal controls and the Martian atmosphere and blah blah blah blah blah, that wouldn't it be worth visiting the issue of a more mobile system?
RE: In situ propellant production
All of this is mostly moot; without a few spare trillions of dollars, nobody is seriously considering the development of these systems, and that is what is "stalling" research.
RE: In situ propellant production
RE: In situ propellant production
CO2+4H2->CH4+2H2O
The methane is stored after the reaction and the water goes through electrolysis after which O2 is stored and H2 is sent back to react with the CO2.
The entire process is heavily dependent on a "sorbent bed", which contains zeolite that adsorbs CO2 at night and is heated during the day to pressurize the system.
Their problem is that in order to "recharge" the zeolite, it must be cooled down further than Mar's ambient, and the other gases that were adsorbed in the bed must be driven off by use of a fan.
Brtrueblood and "monkeydog" - All of this requires more energy obviously, so I thought that maybe someone could give a little feedback on the idea of having the entire plant airborne, which would decrease the need for a fan to drive off the undesirable gases in the sorbent bed, and increase the cooling requirements needed for it; instead I get false information on the actual process of the reaction that produces the propellant, someone actually suggesting a polar lander (which would actually have to drill through several feet of dry ice before hitting water ice), someone who honestly thinks that "solar panels are already marginal as a power source at Mars' distance from the sun" and another who, while not offering any useful reply at all, thinks that my interest lies in a school project.
THANKS
RE: In situ propellant production
No need to take offense to comments.
One of my senior projects in school was to design a turbofan engine for an unpiloted aircraft on Mars (circa 1971). Your questions were going right down the same path I went many moons ago. As you know eng-tips has a policy on students trying to get others to do their homework.
I was just pointing out how your questions seemed.
No apologies,
Monkedog
RE: In situ propellant production
I read Zubrin's Case for Mars papers 20+ years ago as a grad student, researching methods to reject waste heat on Mars for fixed nuclear power plants. They are good studies, but were old when I read them. There's better data out there today.
But all you can do is whine that we're not helping you realize your dream of soaring above Mt. Olympus. Go away, kid, ya bother me.
RE: In situ propellant production
You should have just been honest and up-front here.
thread31-123561: Embry-Riddle a good program?
How's the project coming?
RE: In situ propellant production
RE: In situ propellant production
But thank you for your service and sacrifice.
RE: In situ propellant production
However, it means depending on remote equipment to operate correctly to fuel the return flight. I wouldn't launch the manned mission until a supply of fuel has already been generated on the surface plant. Backup fueling schemes might also be required - who knows what a month of dust storms would do to the connectors? Or a tank leak might do in the eight month trip out to Mars?
If your propellant plant was airborne, the only thing it could pick up would be the CO2. I suppose you could have an essentially coal powered rocket, but off the top of my head, I don't think that it would give you decent Isp. And coal's a solid. Even if it would work in a solid-rocket stup, solid propellants are tough to transfer to an existing engine - you basically have to form them into solid rockets somehow.