Atlas V liftoff from Launch Complex 41.
At 8:02 a.m. MST, NASA ignited the engines of the Atlas V rocket carrying the MSL (Mars Science Laboratory) on its way to Mars. The launch has proceeded very well so far, with the separation of the nose cone fairings. The second stage Centaur rocket is expected to fire at about 8:45 a.m. (Update: Stage firing and spacecraft separation confirmed - MSL is on its way to MARS!).
MSL rover in the lab with scientists.
The MSL rover (named Curiosity) is the largest that has been sent to Mars. Its wide variety of sensors and controls will enable it to explore terrain unaccessible to prior rovers such as Spirit, Opportunity and Pathfinder. Scheduled to land on Mars in August 2012, Curiosity is expected to run a mission length of 23-24 months. Those of you who have been watching Mars rovers so far understand that the craft may last MUCH longer than that.
You can download a PDF fact sheet from NASA at http://www.jpl.nasa.gov/news/fact_sheets/mars-science-laboratory.pdf