The Mars Science Laboratory, the largest and most complex machine that has ever landed on another planet, is on target to launch on Nov. 25 at 7:25 a.m. PST.

“MSL has been assembled, tested, encapsulated, placed atop an ATLAS rocket and is ready to go,” said Doug McCuistion, director of NASA’s Mars Program, during a briefing at NASA headquarters on Nov. 10.

The rover, nicknamed Curiosity, weighs in at nearly 1 ton and is a little bigger than a Mini Cooper. The probe is expected to survey the Martian landscape with HD cameras, examine the chemical surface composition within 20 feet of the rover, monitor the planet’s weather, and search for signs of habitability and life, past or present.

Curiosity also has a six-foot arm that can reach down to place sensors on Martian rocks to investigate their chemical makeup. It will be able to drill inside rocks and deliver samples back to a suite of laboratory instruments carried inside the rover, something never done before in Mars.

“This is a Mars scientists’ dream machine,” said Ashwin Vasavada, MSL deputy project scientist, at the briefing.

MSL’s mission is geared toward investigating the possibility of life on Mars. It will look for organic chemistry and determine if its landing site, Gale crater, could have ever had water or other materials capable of supporting organisms.

The 100-mile-wide Gale crater is composed of layered rock, with the bottom layers made of clays and sulfates, and upper layers containing Martian dust. The area should provide lots of data on the early history of Mars and changes that the whole planet has experience over time.

Once launched, MSL will cruise for eight and a half months to the Red Planet, where it will descend to the surface in August 2012 using an elaborate landing system. It will enter the Martian atmosphere at more than 1,000 mph, parachute to the ground, fire rockets to slow its descent and then hover 600 feet above the ground and lower the rover down on a “sky crane.”

The rover will explore the Martian surface for at least two years and should provide the best data ever obtained about the planet.

“We’re expecting tremendous results,” said MSL project manager Pete Theisinger.

Image: NASA/Glenn Benson