The entry, descent, and landing (EDL) phase begins when the spacecraft reaches the martian atmosphere, about 125 kilometers (about 78 miles) above the surface, and ends with the rover safe and sound on the surface of Mars.

Entry, descent, and landing for the Mars Science Laboratory mission will include a combination of technologies inherited from past NASA Mars missions, as well as exciting new technologies. Instead of the familiar airbag landing of the past Mars missions, Mars Science Laboratory will use a guided entry and a sky crane touchdown system to land the hyper-capable, massive rover.

The sheer size of the Mars Science Laboratory rover (775 kilograms or over 1,700 pounds) would preclude it from taking advantage of an airbag-assisted landing. Instead, the Mars Science Laboratory will use the sky crane touchdown system, which will be capable of delivering a much larger rover onto the surface. It will place the rover on its wheels, ready to begin its mission.

The new entry, descent and landing architecture, with its use of guided entry, will allow for more precision. Where the Mars Exploration Rovers could have landed anywhere within their respective 150 by 20 kilometers (about 93 miles by 12 miles) landing ellipses, Mars Science Laboratory will land within a 20-kilometer (12-mile) ellipse! This high-precision delivery will open up more areas of Mars for exploration and potentially allow scientists to roam "virtually" where they have not been able to before. The entry, descent and landing sequence will break down into four parts:

• Guided Entry - The spacecraft will be controlled by small rockets during descent through the martian atmosphere, toward the surface.

• Parachute Descent - Like Viking, Pathfinder and the Mars Exploration Rovers, the Mars Science Laboratory will be slowed by a large parachute.

• Powered Descent - Again, rockets will control the spacecraft's descent until the rover separates from its final delivery system, the sky crane.

• Sky Crane - Like a large crane on Earth, the sky crane system will lower the rover to a "soft landing"-wheels down - on the surface of Mars.