What is the most ideal space reactor used or planned and If they used that on a electric thruster, which has the highest thrust, what will the speed be? Will it be enough for human deep space travel?
Wouldn't the charged particles from the van allen belts drastically reduce the efficiency of the thin film cells by the time you are in EML2?
Quote from: Raj2014 on 02/16/2015 03:00 pmWhat is the most ideal space reactor used or planned and If they used that on a electric thruster, which has the highest thrust, what will the speed be? Will it be enough for human deep space travel? The Sun is the ideal space reactor in the inner solar system, and yes, solar-electric propulsion is enough for human deep space travel.And the speed depends on how fast you need to go.
...About 1 mm/s (1 N force per 1000 kg vehicle mass) will get you to Mars in 180 day. If you can crank up thrust to 10 mm/s then you get to Mars in ~50 days. Lower the thrust to 0.5 mm/s and the transit takes 250 days. ...
Yes, same as any acceleration rate it would be in units of s^2.I found http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CC8QFjAC&url=http%3A%2F%2Fwww.dtic.mil%2Fcgi-bin%2FGetTRDoc%3FAD%3DADA513936&ei=LbTjVIPDL4HsoASN6oC4Dw&usg=AFQjCNHxL-4st7lrzUUJ8ryVdkY7mrtXKw&sig2=Ff5jujM1ebpyCb6YuCd71w&bvm=bv.85970519,d.cGUPaper from the Airforce with a nice summary of HALL, VASIMIR and ELF thrustersNested HALL (X3) 0.5 kg/kw (thrusters) 1.4 kg/kw (Thruster and PPU)VASIMIR 1.5 kg/kw (thrusters) Ad-Astra estimates 10MW device would be 4 kg/kw ELF 0.25 kg/kw (thrusters) 0.7 kg/kw (Thrusters and PPU)I think this shows rather clearly why VASIMIR has fallen out of favor vs HALL and why ELF and similar Reverse-Field-configuration designs are attractive as the next follow-on technology. ELF + 1kw/kg solar is an 'alpha' value of near 2, look at any of the VASIMIR papers and that's near the Alpha value they were needing for some of the insanely short 40 days to Mars ideas (anything under 3 months is total overkill in my opinion).
DS4G 19,000s
It has to be done.
Follow up on earlier testing question: It appears that 100 kw and above class thruster development is running into a problem, their are hardly any vacuum chambers that are large enough and can draw a vacuum rapidly enough to accommodate the propellent flow rates these things are capable of. The upper end of the power range of the X3 could only be tested at Glenn, which is the NASA epicenter of Electric Thruster R&D. ...
Quote from: Impaler on 02/18/2015 05:12 pmFollow up on earlier testing question: It appears that 100 kw and above class thruster development is running into a problem, their are hardly any vacuum chambers that are large enough and can draw a vacuum rapidly enough to accommodate the propellent flow rates these things are capable of. The upper end of the power range of the X3 could only be tested at Glenn, which is the NASA epicenter of Electric Thruster R&D. ...Yeah, I was just going to suggest Glenn (I was an intern there). They have several that are very large and with high pumping capacity. Especially if you include the (also in Ohio) Plum Brook facility (which isn't normally used for electric propulsion, but they have the biggest thermal vacuum chamber in the world with high pumping capacity and also another very large one... the biggest one was originally built for testing space nuclear power).
NASA has access to a huge vacuum chamber, its attached to ISS.
If your device can only be tested in space it's really DOA.
Re: Using ISS...Quote from: Impaler on 02/18/2015 05:12 pmIf your device can only be tested in space it's really DOA.{sigh} Speaking of creating a vacuum, we really suck at doing space.This came up in the rotating-station thread. What do we have a multi-billion dollar per year permanently manned space station for if not to use it to develop advanced technology for next-gen systems? Precisely things like centrifuges and experimental ion drives that are hard/impossible to test on Earth. Not crystals and student contests and half-hearted "commercialisation" of research.