The SpaceX Falcon 9 rocket, complete with "hypersonic grid fins," that SpaceX will attempt to land on a floating platform in the Atlantic Ocean as part of a Dec. 16, 2014 launch.

from space.com 

SpaceX attempt something truly epic during next week’s cargo launch to the International Space Station.
During the Dec. 16 launch from Florida’s Cape Canaveral Air Force Station, which will SpaceX’s robotic Dragon capsule toward the orbiting lab, the California-based company will try to bring the first stage of its Falcon 9 rocket back to Earth for a controlled on a floating platform in the Atlantic Ocean.

The bold maneuver marks a step in SpaceX’s development of reusable-rocket technology, which the company’s billionaire founder, Elon Musk, says could eventually cut the cost of spaceflight by a factor of 100 and perhaps make Mars colonization economically feasible. 

Musk shared photos of the Falcon 9 and landing platform via late last month, ratcheting up interest in the cargo mission, the fifth of 12 unmanned resupply flights SpaceX will make to the space station for under a $1.6 billion contract.

“Autonomous spaceport drone ship. Thrusters repurposed from deep sea oil rigs position within 3m even in a storm,” Musk tweeted about the platform on Nov. 22. “Base is 300 ft by 100 ft, with wings that extend width to 170 ft. Will allow refuel & rocket flyback in future,” he added in another tweet.

The Falcon 9 photo revealed that the rocket is outfitted with “hypersonic grid fins” to increase stability during a return to Earth.
“Grid fins are stowed on ascent and then deploy on reentry for ‘x-wing’ style control,” Musk tweeted on Nov. 22. “Each fin moves independently for pitch/yaw/roll.”

At a conference at MIT in October, Musk said that SpaceX would attempt to land the Falcon 9 first stage on the floating platform during the rocket’s next flight. The next liftoff on the rocket’s schedule is the Dec. 16 Dragon launch.

Musk estimated a 50 percent chance of success for the platform landing on the first attempt, but said the odds would improve on subsequent .