Unless there are unprecedented advances in spacecraft propulsion systems the human species won’t be travelling to planets orbiting other stars any time soon – if ever. However, despite the great expense, space exploration in our own solar system is possible, with trips to Mars having a return journey time in the scale of years.

Within the last few years, it has been indicated to NASA that funding will be made available for a manned mission to Mars. As well, other missions with a more international flavour have been contributing to the exploration of the solar system. For example, the Cassini / Huygens joint NASA and European Space Agency robotic exploration of Saturn was an enormous success. Perhaps the greatest moment was the stunning 2005 landing of the Huygens probe on the surface of Saturn's moon Titan, revealing in it's descent mountains with river-like drainage channels, and a -180 celsius spongy surface, strewn with ice boulders.

Looking back on the history of NASA robotic probes the prevailing belief was to direct experiments to bodies in the solar system which at least had the potential for water. Moving forward, the NRC report proposes alternative liquid environments in which life may be possible, in some cases within extreme temperature ranges, or highly acidic or alkaline solutions. The report committee recommends a range of laboratory, field studies and space explorations to further test the conditions in which life may make a foothold on. One of the possible benefits of the investigations which have been proposed in the NRC report is that in the not too distant future when human beings finally begin to colonise other worlds they will most likely reap the benefits of this research and have available to them new methods and technologies to grow food, find water, or otherwise interact with the local environment in useful ways.

For more information

SETI - The Drake Equation
http://www.seti.org/site/pp.asp?c=ktJ2J9MMIsE&b=179073

NASA - Multimedia - Huygens probe landing on Titan
http://www.nasa.gov/mission_pages/cassini/multimedia/pia08117.html