Curiosity Sheds Its Cruise Stage
NASA's Mars Science Laboratory carrying the Curiosity rover has separated from the cruise stage that carried it from Earth to the Red Planet. The rover, snug between a protective back shell and heat shield, is about 10 minutes away from entering the Martian atmosphere and about 17 minutes away from landing. Thrusters on the back shell are orienting the spacecraft so the heat shield faces forward in preparation for entering the atmosphere. At this stage, the Mars Science Laboratory Entry, Descent and Landing Instrument (MEDLI) suite begins taking measurements related to the performance of the heat shield that will aid in the design of future missions.
Sailing Through the Martian Atmosphere
NASA's Mars Science Laboratory has entered the Martian atmosphere. The top of Mars’ atmosphere is a gradual transition to interplanetary space, not a sharp boundary. In addition, the entry point is not directly above the landing site. While descending from that altitude to the surface, the spacecraft will also be traveling eastward relative to the Mars surface, covering a ground-track distance of about 390 miles (about 630 kilometers) between the atmospheric entry point and the touchdown target. Two tungsten weights will be released to shift the spacecraft's center of mass and give it the lift it needs to fly through the atmosphere.
Parachute Pops Open
The parachute guiding NASA's Mars Science Laboratory to the surface of Mars has opened. At this point, the rover has already slowed down considerably due to friction with the atmosphere. The parachute, which is 51 feet (nearly 16 meters) in diameter, deploys about 254 seconds after entry, at an altitude of about 7 miles (11 kilometers) and a velocity of about 900 mph (about 405 meters per second).
Curiosity Lands on Mars
NASA's Curiosity rover has landed on Mars! Its descent-stage retrorockets fired, guiding it to the surface. Nylon cords lowered the rover to the ground in the "sky crane" maneuver. When the spacecraft sensed touchdown, the connecting cords were severed, and the descent stage flew out of the way. The time of day at the landing site is mid-afternoon - about 3 p.m. local Mars time at Gale Crater. The time at JPL's mission control is about 10:31 p.m. Aug. 5 PDT (early morning EDT).