Orchestrating an “Unusual” Landing

Aerojet has made all of the thrusters ever used on a United States Mars Mission, and Mars Science Laboratory is no exception. MSL carried eight MR-111C 1.0 lbf thrusters used for trajectory correction maneuvers during cruise and eight Aerojet 68 lbf thrusters (very similar to the Phoenix landing thrusters) that stabilized the spacecraft during its entry to Mars.

After parachute deployment, MSL performed final descent to near the Martian surface using its eight 700 lbf throttling engines.  These engines are descended from the Viking lander engines.  A tether lowered the rover onto the Martian surface and the descent stage flew succesfully away.

The entry, descent and landing portion of the mission was very unusual. Viking, the first of the Mars landers, used Aerojet throttleable engines to power its descent onto the Martian surface. The Viking lander was equipped with 18 nozzle bells, arranged in a plume-cancelling pattern to avoid disturbing the Martian regolith since without a rover, the two Viking spacecraft would perform all of their science in place.

Mars Pathfinder, Mars “Spirit”, and Mars “Opportunity” delivered their rovers using a parachute and airbag system dropped from the spacecraft. Mars Phoenix used an actively guided descent system but was searching for ice on Mars so clearing the regolith using the thrusters was a benefit.

The Mars Science Laboratory spacecraft was launched aboard the Atlas 541 equipped with four Aerojet solid motors providing 380,000 lbf of thrust each at lift-off, eight separation motors, and twelve 5-lbf class roll, pitch, yaw and settling burn thrusters on the Centaur upper stage. Launch date was November 26, 2011.

Mars Science Laboratory cruised to the red planet, loaded with Aerojet hardware and destined for the most complicated landing ever.

The spacecraft landed on Mars Aug. 6, 2012 at 6:31 AM GMT, meaning it set down Sunday, August 5, 2012 at 10:31 Pacific Daylight Time.  While not the most convenient time to stage a party, you can be sure we fully celebrated her landing first thing Monday morning!