Planning for a Manned Mission to Mars

[alokmohan]

The space elevators would in theory reduce the cost of putting material in orbit.

Larger craft/stations orbiting between Mars and Earth have been given serious consideration.

A continuous acceleration system requires lots of energy, depending of course, on the required level of acceleration.  A thrusting system would require very high Isp to be effective, while something that uses the solar wind would probably use less energy but would achieve low acceleration.

                                                                                                          With discovery of nano carbon molecules space elevator is going to be a reality now.

[Rxke]

The problem with the elevator is the chicken/egg thing.

Yes, it will be economical IF it is used to the fullest. But...
Imagine it is built, there is no market for it to keep being used to the fullest for more than a year. Its capacity is too big... And maintaining a non-'launching' cable won't be cheap. It needs quite an infrastructure to keep it in good shape.
Good news is that some big energy corp is mightily interested if they could really get the price down to 100$/pound. They'd invest in solar farms, giving it work for 'ages'.

Bad news... the nanocables. They really need *very* strong cable, hovering around the theoretical maximum. Which won't be simple. It's going fast now, because potential payback is big, but once you have cheap carboncable, say 10x stronger than steel, and it costs you $$$$$ to develop 11x cable.... Most companies will say: 10x is plent to make megabucks... On Earth (bridges and stuff) cost/profit balance to go for stronger cable won't be interesting...
A few indrgrads will be working on the 'ultracable' but it will go slow... Unless some government or big company is visionary enough to go on...

[Astronuc]

I just had to post this link. 

http://science.nasa.gov/newhome/headlines/prop12apr99_1.htm

It may be eslewhere in the forum, but it's worth putting it here.

Someone was very optimistic 6 years ago.

[Astronuc]

4Frontiers is a start-up that developed out of an MIT course. It's objective is to develop the technical systems leading to the creation of the first permanent Mars settlement. In addition to their research activities, they are pursing near term revenue streams in informative entertainment and consultancy business segments. These planned activities include a full scale, technically accurate, Mars settlement mockup to be located in central Florida.

4Frontiers completed last year an 8 month technical feasibility study of this first permanent Mars settlement designed for 12 to 24 people, putting in place the initial industry, agriculture, acquaculture, health, mining, energy and habitation facilities such that these settlers can begin to work towards material self sufficiency. Some of what was generated from that study is available on their website.

http://www.4frontierscorp.com/joomla/

Cool!

[Astronuc]

http://www.marshome.org/about/

http://www.marshome.org/about/technology_focus.html