Main Page Favorable Time to Build on Experiencer Getting to Mars Science Instruments Persistent Spirit Well-Placed Opportunity Extension Project/Program Management Mars Exploration 　 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Red Rover Goes to Mars

Getting to Mars

Both rovers were launched from Cape Canaveral Air Force Station on central Florida・s Space Coast. Spirit ascended in daylight on June 10, 2003. Opportunity followed with a nighttime launch on July 7 after several days of delays for repairing cork insulation. During the cruise to Mars, Spirit made four trajectory correction maneuvers. Opportunity performed three. The two spacecraft survived blasts of high-energy particles from some of the most intense solar flares on record. To prevent possible problems from the flares' effects on computer memory, mission controllers commanded rebooting of the rovers・ computers, a capability originally planned for use on Mars but not during the cruise. Each rover made the trip tightly tucked inside its folded-up lander, which was encased in a protective aeroshell and attached to a disc-shaped cruise stage about 2.6 meters (8.5 feet) in diameter. The cruise stage was jettisoned about 15 minutes before the spacecraft reached the top of Mars・ atmosphere. With the heat-shield portion of the aeroshell pointed forward, the spacecraft slammed into the atmosphere at about 5.4 kilometers per second (12,000 miles per hour). Atmospheric friction in the next four minutes cut that speed by 90 percent, then a parachute fastened to the backshell portion of the aeroshell opened about two minutes before landing. About 20 seconds later, the spacecraft jettisoned the heat shield. The lander descended on a bridle that unspooled from the backshell. A downward-pointing camera on the lander took three pictures during the final half-minute of the flight. An onboard computer instantly analyzed the pictures to estimate horizontal motion. In the final eight seconds before impact, gas generators inflated the Lander・s airbags, retro rockets on the backshell fired to halt descent speed, and transverse rockets fired (on Spirit・s lander) to reduce horizontal speed. The bridle was cut to release the lander from the backshell and parachute. Then the airbagencased lander dropped in free fall.
Spirit landed on Jan. 4, Universal Time (at 8:35 p.m. Jan. 3, Pacific Standard Time). It bounced about 8.4 meters (27.6 feet) high. After 27 more bounces and then rolling, it came to a stop about 250 to 300 meters (270 to 330 yards) from its first impact. Spirit had journeyed 487 million kilometers (303 million miles). JPL navigators and engineers successfully put it only about 10 kilometers (6 miles) from the center of its target area. Coordinates of Spirit・s landing site are 14.57 degrees south latitude and 175.47 degrees east longitude.
Opportunity landed on Jan. 25, Universal Time (at 9:05 p.m. Jan. 24, Pacific Standard Time). It traveled about 200 meters (220 yards) while bouncing 26 times and rolling after the impact, with a 90-degree turn northward during that period. It came to rest inside a small crater. One scientist called the landing an ：interplanetary hole in one.； Opportunity had flown 456 million kilometers (283 million miles) from Earth and landed only about 25 kilometers (16 miles) from the center of the target area. The landing- site crater, later informally named ：Eagle Crater,； is about 22 meters (72 feet) in diameter, 3 meters (10 feet) deep. Its coordinates are 1.95 degrees south, 354.47 degrees east.