> I think it takes about 2500m/s delta V to get from from LEO to a GTO. > How feasible is it to use some type of an electric thruster (high > specific impulse but low net thrust - eg a hall effect thruster or > similar device) to slowly crawl up to GTO from LEO?
Hi Ross, Very feasible, there are a number of CubeSat projects that are trying to do exactly that. It seems the problem these projects have is getting a launch - it's not easy. For example two projects, Project Calliope and Euroluna, will both be testing Ion Motors. They booked a launch on the same rocket some 3 years ago now, as yet the rocket hasn't launched. http://amsat-uk.org/2012/06/20/interview-with-author-of-diy-satellite-platform/ http://amsat-uk.org/2013/03/01/ion-propulsion-euroluna-update-on-cubesat-ht-power-supply/ They seem they are plenty of other projects also planning to use CubeSat propulsion but in all cases launch availability/cost seems to be the limiting factor. I'm sure many of these projects will eventually get up there and who knows maybe one or two might even work as intended first time, others may need two or three launches before everything is perfected. I think over the course of the next 5-10 years we should have viable CubeSat propulsion systems that can go from a 310 km orbit to HEO, may take a few years of flight to get there but I'm sure it can be done. Of course they'd need to address the radiation issues that Brent mentioned, although a CubeSat that simply went from 310 km to a slightly less hazardous 1400 km orbit would be good. BTW the Lunar Pocket Spacecraft project, announced in June, is another one planning to use propulsion, see http://amsat-uk.org/2013/08/26/uk-radio-hams-lunar-cubesat-to-go-ahead/ 73 Trevor M5AKA _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
