Some time ago I read of a proposal for making, eventually, trips to Mars easier. Basically, it was to nudge the orbit of an Apollo asteroid so that it passes near Earth on its inner end and Mars on its outer end. Lighters would ferry people and freight to the now shuttle when it passes by to hop off at the other end. This would take some timing – you want the planet there when the asteroid passes by after all – and I’m wondering how long the trip would take and how often the windows for a multi-asteroid shuttle fleet would be.
I’ve done some googling and the best I could come up with was a Discover article. It doesn’t say much about what I’m looking for. Can anybody out there point me to some more information or perhaps a program that would calculate it out?
What you’re looking for is called a Mars Cycler orbit. There are various cycles that could be used that have various transit times. The one proposed by Buzz Aldrin in 1985 would take 146 days to get from Earth to Mars, spend the next sixteen months beyond the orbit of Mars then 146 days from Mars to Earth.
Perfect, Santos! Now that I know what to look for, I found this site with an animation of the orbits. It would actually be a pair of cyclers, one with the fast leg Earth-to-Mars, and the other with the fast leg Mars-to-Earth. The cycle repeats every 26 months so with the first pair in operation you could have a two-year wait for the trip, but as the traffic grew heavier, additional pairs could be added. People and urgent freight would take the crewed five month fast leg, a lot quicker than your typical nine month Hohmann transfer to Mars. Ordinary freight could take the non-crewed 16 month slow leg.
Of course you still have to match velocities at the beginning and end of your trip so it isn’t a free ride; but at least you can build up the equivalent of a permanent space station doing the loops, so you can limit the mass you have to boost to just passengers and expendables. Not having to relaunch crew accommodations and heavy radiation shielding each and every trip would be an enormous savings.
Right. You’d still need to accelerate your astronauts up to the same orbit as if they were flying to Mars on their own. Unless maybe they can work out a way to shoot out a cable, snag the asteroid as it zips past and haul themselves in.
They may also stock up the cycler station from unmanned cargo vehicles that travel via more leisurely, fuel efficient routes.
Damninteresting!!! That is a great site with lots of really interesting articles (as the name suggests). I used to hang out there a few years ago, but the guy who runs the site took a hiatus for a couple years when he wrote a book and it was sort of a ghost town for a while. There was a great little community in the comments sections of the articles that basically went away when they stopped updating the site, and I actually found the SDMB when I was looking for somewhere else to hang out online.
