Computerworld / By James Mulroy

PC World - On Friday, at 10:25 am Eastern, the Mars Science Laboratory (MSL) mission will rocket into the sky on a 191-foot-tall Atlas V rocket and begin its mission to Mars. While the MSL rover, Curiosity, is sitting on top of the Atlas V rocket, NASA is making its final preparations for the first launch opportunity, and tweeters are preparing for a two-day launch tweetup.

The MSL is an important Mars mission that will perform the first-ever precision landing--using a guided entry system--on Mars; analyze the soil for organic compounds; investigate the composition of the Martian surface; and determine the Martian atmospheric cycling and processes, as well as a number of other atmospheric conditions that could help determine the past and future habitability of Mars.

That last one is important -- we may finally have the answer to whether life has ever existed on Mars.

According to NASA, Curiosity is twice as long and five times as heavy as previous Mars rovers Spirit and Opportunity; it will also carry instruments that weigh 15 times as much as the previous Mars rover payloads, and according to the New York Times, the total cost of MSL is about $2.3 billion.

Currently, NASA is preparing for launching the mission on Friday -- the first launch opportunity. If weather or other conditions prevent launch then there will be other launch windows through Dec. 18r. The rover is expected to land on Mars in August 2012 and the mission will last for 686 Earth days.

For tweeters out there, NASA has invited 150 followers of NASA's Twitter account to a two-day Tweetup between Wednesday and Friday at the Kennedy Space Center in Florida. The Tweetup participants will share their experience at the center and the launch with their Twitter followers and on other online forums. So make sure to stay tuned to the Twitter hastag #NASATweetupon the day of the launch.

Also, you don't want to miss this historic launch, so make sure to watch the live broadcast at the NASA Tweetup Ustream channel. Additionally, you may be able to watch at any one of the following (these have covered Shuttle launches in the past, but no guarantee if they don't cover this launch, although, they probably will):

1. NASA TV

2. Spacevidcast

3. Spaceflight Now

To learn more about the MSL mission make sure to visit the NASA MSL main page and some of our previous coverage on Curiosity!