After the mess over the moon program, those nice people over at the mars society decided that they were not going to get anywhere towards manned exploration of mars by waiting for NASA to come up with a plan of their own.

This plan eventually got written up by Robert Zubrin in his excellent book "the case for mars", which gives a wondefully detailed account of how to get to mars using current technology for a fraction of the NASA price tag.

Here is a brief overview:

mars direct sends an atmosperic fuel generator to mars over a year in advance (launched directly, from existing ground based rockets). Once this reports full tanks, you can send your manned ship, which doesn't need to be much more than twice the size of skylab.

you can rotate this on the end of a gantry, giving you centrifugal gravity, and thus no muscle wastage problems.

when it arives at mars, most of it goes into orbit, as a martian equivalent of the international space station.

you then detach the lander, which can home in on a radio beacon from the fuel generator. Among other things, this means that you don't have to take the fuel with you for the return trip.

You can then take a few months doing a detailed exploration of your landing site, and when it is time to go home, you just fill up your fuel tanks, and blast off back into martian orbit.

Once back in martian orbit, you can easily return to earth, using the same methods that you used to get to mars. What is more, there is nothing to stop you sending a fuel generator and manned capsule every eighteen months.

Once you have found an appropriate site for a permenant base, you can easily leverage this technology to rapidly give you a working mars colony, and the mars spacestation makes the perfect jumping off point for asteroid mining missions.

For further information, look at the Feature on mars direct at pescu.net