Too bad we can't send Ben Affleck and Bruce Willis too, but hey, whaadyagonna do?
For those interested, here are the sites you can keep up to date on the launch.
Deep Impact Main Page
View NASA TV Launch Coverage
View Live Online Launch Countdown Coverage
View Press Kit
The Deep Impact objectives are:
1.)Observe how the crater forms
2.)Measure the crater's depth and diameter
3.)Measure the composition of the interior of the crater and its ejecta
4.)Determine the changes in natural outgassing produced by the impact
Also, one thing that will be closely monitored is the degree of orbital change that is caused by the impact. This will be a good thing to know. It will hopefully help to forward our knowledge of how effective we can be in mitigating comets in the future.
Congratulations to the staff of Deep Impact from Nasa, Jpl, Cal Tech and the University of Maryland. Godspeed, as they say......