In-situ Exploration and Sample Return Technologies: Entry, Descent, and Landing: Sky Crane

CAD/CAM Drawing of Sky Crane and Rover This drawing shows how the rover would be lowered on a tether during entry, descent, and landing (EDL). Image Credit: NASA/JPL

Mars Science Laboratory represents the first use of a "soft-landing" technique employed at Mars. The sheer mass of Mars Science Laboratory prevents engineers from using the familiar airbags to deliver their rover safely to the martian surface. As rovers become more capable and carry more instruments, they become larger. So, in order to accommodate this advanced mission, engineers designed a sky-crane method that will lower the rover to the surface.

After the parachute has significantly slowed the vehicle and the heatshield (that has protected the rover during entry) separates, the descent stage will separate from the backshell. Using four steerable engines, the descent stage will slow the nested rover down even further to eliminate the effects of any horizontal winds. When the vehicle has been slowed to nearly zero velocity, the rover will be released from the descent stage. A bridle and "umbilical cord" will lower the rover to the ground. During the lowering, the rover's front mobility system will be deployed so that it is essentially ready to rove upon landing. When the on-board computer senses that touchdown is successful, it will cut the bridle. The descent stage then pitches away from the rover and powers away at full throttle to a crash-landing far from Mars Science Laboratory.