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Mars Science Laboratory

Entry, Descent, and Landing

Curiosity Spotted on Parachute by Orbiter
NASA's Curiosity rover and its parachute were spotted by NASA's Mars Reconnaissance Orbiter as Curiosity descended to the surface on Aug. 5 PDT (Aug. 6 EDT).

The entry, descent, and landing (EDL) phase began when the spacecraft reached the Martian atmosphere, about 78 miles (about 125 kilometers) above the surface, and ended with the rover safe and sound on the surface of Mars at 10:32 p.m. PDT on Aug. 5, 2012 (1:32 a.m. EDT on Aug 6, 2012).

Entry, descent, and landing for the Mars Science Laboratory mission included 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 used 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 (over 2,000 pounds or 900 kilograms) precluded it from taking advantage of an airbag-assisted landing. Instead, the Mars Science Laboratory used the sky crane touchdown system, which is capable of delivering a much larger rover onto the surface. It placed the rover on its wheels, ready to begin its mission at Gale Crater.

The new entry, descent and landing architecture, with its use of guided entry, allowed for more precision. Where the Mars Exploration Rovers could have landed anywhere within their respective 93 miles by 12 miles (150 by 20 kilometers) landing ellipses, Mars Science Laboratory landed within a 12-mile (20-kilometer) 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 breaks down into four parts:

  • Guided Entry - The spacecraft was 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 was slowed by a large parachute.
  • Powered Descent - Again, rockets controlled the spacecraft's descent until the rover separated from its final delivery system, the sky crane.
  • Sky Crane - Like a large crane on Earth, the sky crane system lowered the rover to a "soft landing" - wheels down - on the surface of Mars.

Revised Landing Target for Mars Rover Curiosity
This image shows changes in the target landing area for Curiosity, the rover of NASA's Mars Science Laboratory project.

Scene of a Martian Landing
The four main pieces of hardware that arrived on Mars with NASA's Curiosity rover were spotted by NASA's Mars Reconnaissance Orbiter (MRO).

Orbiter View of Curiosity From Nearly Straight Overhead
Details such as the shadow of the mast on NASA's Mars rover Curiosity appear in an image taken Aug. 17, 2012, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter, from more directly overhead than previous HiRISE images of Curiosity.