Betina Pavri speaks to a group of Tweetup participants at NASA Kennedy Space Center's Press Site in Florida during prelaunch activities.

Betina Pavri, systems engineer at NASA's Jet Propulsion Laboratory (JPL), speaks to a group of Tweetup participants at NASA Kennedy Space Center's Press Site in Florida during prelaunch activities for the agency’s Mars Science Laboratory (MSL) launch as Allen Chen, also a systems engineer at JPL, looks on, at left.

Following a series of briefings, participants will tour the center and get a close-up view of Space Launch Complex-41 on Cape Canaveral Air Force Station. The tweeters will share their experiences with followers through the social networking site Twitter. MSL's components include a car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Liftoff of MSL aboard a United Launch Alliance Atlas V rocket from pad 41 is planned during a launch window which extends from 10:02 a.m. to 11:45 a.m. EST on Nov. 26. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Jim Grossmann