The idea of a citizen's space program, as
opposed to a government one, appeals to me. It is of course ridiculous, but
one can do worse than play. If nothing else, it might shame governments into
being a little more forward-thinking about making it into the space age.
A space-craft could also use
a magnetic sail,
deflecting solar (or interstellar) wind, or interacting with the magnetic field
of a planet.
JP Aerospace, with plans to
fly airships into space, is a volunteer-based space program, very much along
the lines of what I'm describing here – and actually running missions to
the edge of space since 1999.
Tethers Unlimited implements
technologies that enable low-cost orbital manoeuvring
and momentum exchange
tethers. The the former tether, a cable hanging off a satellite, is radially
aligned by tidal forces; currents in it can couple to Earth's magnetic field to
produce forces the satellite can exploit to manoeuvre. The latter tether
connects two objects in orbit; tension in it transfers momentum between the two
objects; combined with the difference in local gravity between the two ends,
this can be exploited in diverse ways. Neil Stephenson's novel
Anathem exploits both to get
some characters stealthily into a desired orbit.
Update: mid-summer, 2004 (I think actually the day before the solstice),
the first non-government astronaut made it to space and safely home again,
aboard SpaceShipOne. Other exciting developments are afoot, as well.