First Mars Robotic Explorer

NASA’s Mars rover Spirit, which landed on Sunday, is in fact the first Mars robotic explorer. NASA’s Mars Pathfinder and its rover Sojourner successfully touched down on Mars in 1997, but the BBC evaluated that it was just a test rover.

The golf cart-sized Spirit is 17 times and four times larger than Sojourner in weight and size respectively. While Sojourner could only move forward about 20 meters, Spirit is equipped with eight cameras, a microscope, an infrared spectrometer and a robot sampling arm.

Spirit is designed to seek traces of water in the Gusev Crater, which is believed to have been the site of an ancient lake. Pictures sent by Mars explorers show traces of river and lakes on the Martian surface.

Scientists estimate that Mars had water on its surface about 73,000 years ago when it was much warmer.

Meanwhile, Spirit’s identical twin Opportunity will sample minerals on the opposite side of the Gusev Crater sometime on January 24. The rovers are robotic geologists, exploring to find evidence that the planet once had life on it. NASA spent $820 million on this project.

NASA’s explorers failed to land Mars twice, including the Mars Polar Lander in 1999. British Mars explorer Beagle 2 also ended in failure last December. But, this time Spirit successfully touched down on the Martian surface.

Only one-third of the more than 30 spacecrafts that have attempted to reach or orbit Mars made it since Mars is far from the Earth and its weather and geographical conditions are not fully understood. Nine attempts were made to land on Mars before Spirit, but only three, all American, made it.

Unfortunately, the current stage of technology prevents an explorer to land on a specific site of Mars. This time, NASA targeted to land the rovers on a 60 by 15 kilometer range area in the Gusev Crater.

The U.S. has plans to send up a Mars spacecraft every 26 months because the distance between the Earth and the Mars is the shortest every 26 months.

Ki-Tae Kwon kkt@donga.com