Mars Polar Lander Mission Status
21 Jan 1999
(Source: Jet Propulsion Laboratory)
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JET PROPULSION LABORATORY
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Mars Polar Lander successfully completed its first trajectory correction maneuver at 4:30 a.m. Pacific Standard Time today to fine-tune its flight path to Mars. The maneuver, which lasted 3 minutes, removed a small bias in the lander's trajectory that was introduced at launch to send the third stage of the Delta II rocket, which was trailing behind the spacecraft, past Mars rather than directly toward the planet. The maneuver also corrected minor injection errors caused by the spacecraft's liftoff from Earth on January 3, 1999.
The spacecraft was turned 180 degrees in preparation for the maneuver, in which it fired four of its eight thrusters. After the burn was completed, Mars Polar Lander automatically slewed itself back to its standard orientation for the early cruise phase of its journey to Mars. In this configuration, the lander's solar arrays, which are shaped like gull wings, are pointed about 20 degrees away from Earth to allow the spacecraft to generate enough solar power for onboard operations and still support daily communications with Deep Space Network ground stations. The maneuver changed the spacecraft's velocity by about 16 meters per second (35.8 miles per hour).
Mars Polar Lander remains in excellent health. Three science investigations aboard the spacecraft - the Mars Volatiles and Climate Surveyor instrument package, Mars Descent Imager and Light Detection and Ranging (Lidar) instrument - are currently turned off. The flight team will conduct an initial health check of the Mars Volatiles and Climate Surveyor's meteorology instrument package on or about February 3.
Today the spacecraft is 5.2 million kilometers (3.2 million miles) from Earth, receding at a velocity of 3.3 kilometers per second or 11,800 kilometers per hour (7,322 miles per hour).