PASADENA, Calif., Feb. 11 — Cold on Mars forced NASA to keep its Spirit rover parked for a day, interrupting a planned monthlong drive to a nearby crater, the space agency said Wednesday.
NASA could not send commands to Spirit late Tuesday because the cold prevented the rover from rotating a high-gain antenna toward Earth. The rover’s motors, used to position the antenna, were under a frigid shadow.
“It’s very similar to starting your car on a cold day,” said project manager Pete Theisinger.
NASA routinely warms the motors by passing an electric current through them. However, engineers had not set the current limit high enough to compensate for the lower-than-normal temperature of the shaded motors.
The space agency got the antenna pointing in the right direction later in the day. By then, it was too late to continue the journey.
Temperatures on Mars can reach 100 degrees below zero Fahrenheit (-70 degrees Celsius), which is about the coldest it gets at Earth's South Pole.
NASA planned for Spirit to resume moving overnight Wednesday, when scientists want it to travel nearly 83 feet (25 meters) toward a crater about 800 feet (250 meters) away.
Earlier this week, Spirit traveled a record 70 feet (21.2 meters) across the rocky Martian surface. Scientists planned for Spirit to reach the crater within the next three weeks.
Spirit’s twin, Opportunity, continued to scoot along a rock formation at its landing site halfway around the planet. It has been taking detailed pictures of the finely layered rocks. Initial results suggest the rocks formed from volcanic ash or compacted, windblown dust.
NASA sent the two rovers on an $820 million mission to look for geologic evidence that ancient Mars had liquid water for a long enough time to permit the development of life.
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