"I'd rather see Mars hit than Deimos. It's more important to find ice on Mars than on that little rock of a moon."<br /><br />Ah, no. The presence of surface and subsurface ice on Mars is already known. The only thing Thor will give us is some more detail about ice in lower Martian lattitudes. Nice to know but not vital.<br /><br />Deimos ice on the other hand is still a mystery. And the presence of easily recovered ice on Deimos could revolutionize plans for manned missions to Mars and accelerate possible timelines. Deimos is much more easy to reach from Earth than the surface of Mars, so Deimos could provide the ideal refuelling location and enable simple and cheaper travel to Mars itself. <br /><br />Plus, if handled imaginatively, not only could an impact mission discover Deimos ice, it could also provide the means for a limited (and really cheap) Deimos sample return mission! If the impact observing flyby-spacecraft is on a free-return trajectory (easy to do) and provided with aerogel sample-collection pads (just like the Stardust comet sample return mission), it might be possible to scoop up a tiny amount of Deimos debris blown out into space by the collision.<br /><br />
http://stardust.jpl.nasa.gov/home/index.html<br /><br />"I wonder if they could squeeze that into the next launch window. So far the pattern has been orbiter, lander, orbiter, lander. So I wonder if they will send Thor now instead of MSL or bump Thor to the launch window after. Too bad they can't send both."<br /><br />MSL will launch in 2009. From the Thor link I provided...<br /><br />"If approved by NASA, the mission [Thor] would launch in 2011."<br /><br />
http://www.marsdaily.com/reports/THOR_Mars_Mission_To_Seek_Underground_Water.html<br /><br />Thor is a cheap mission, that is the main appeal. Thor is not going to