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Last ship in Mars-bound armada begins risky tripNASA's Opportunity rover launched after nearly two-week delay
By Richard Stenger
(CNN) -- A robotic voyager has started an interplanetary cruise after almost two weeks of delays, joining four other ships that will attempt to unlock the secrets of the red planet, including whether it ever held life. The craft, a six-wheel NASA rover, thundered into the night sky over the Florida coast late Monday, riding atop a Delta rocket launched from Cape Canaveral Air Force Station. The liftoff was originally slated for late June but was pushed back five times because of bad weather, problems with rocket insulation and the need to replace a battery used in a self-destruct mechanism should the launch vehicle have gone astray. And on Monday, a last-minute glitch with a rocket valve halted a launch attempt just seconds before launch. But within the hour, after tests determined that the valve was working, the rover mission finally got off the ground at 11:18 p.m. EDT. Named Opportunity, the rover follows in the space steps of its identical NASA twin, Spirit, which left for Mars on June 10; Europe's Mars Express-Beagle 2 mission, a duo that blasted off June 2; and Japan's Nozomi orbiter, which left for Mars in 1998. "The launch is a milestone, but just one of many along the way. Landing historically is where the most risk is involved," said Steve Squyres, lead mission scientist for the twin rovers, which together cost $800 million. "We're using the same landing technique that Pathfinder used," Squyres said, referring to the inflatable balloon system that cushioned the impact of the last successful Mars lander in 1997. The new quintet should arrive in the Mars system to begin their scientific operations in December and January, if they survive the trip. Just reaching the red planet would be a significant accomplishment. Of about 30 attempts to reach Mars, only one-third have worked; only three of nine tries at landing have succeeded. The solar-powered, golf cart-size droids will try to touch down on opposite sides of Mars and roam around for at least three months. They are designed to find physical evidence of water activity from billions of years ago, when the planet was thought to have been wetter and warmer -- and possibly inhabited by microbes. 'There's a long way to go'Europe's $300 million mission includes two craft, the Mars Express orbiter and the Beagle 2, which will drop from the main craft for a balloon-cushioned landing, where it will sniff, dig and bake soil samples for signs of life. Collin Pillinger, the main mission scientist for the British-built Beagle 2, is as wary of the trip hazards as his NASA counterpart, Squyres. "Don't get excited yet. There's a long way to go," he said. "This mission is not over until we have the science returned."
The Mars Express orbiter will conduct geology and hydrology studies while floating high above the red planet. But even Mars satellites face risky odds when they arrive. NASA lost two missions to Mars in 1999, which included an orbiter that burned up in the Martian atmosphere because of a mix-up of English and metric propellant measurements. Nozomi, which means "Hope," is aptly named: the $88 million mission has needed plenty of it. It was expected to arrive at Mars in October 1998, but after a near-fatal thruster malfunction guzzled much of the craft's propellant, Japanese engineers plotted a new course, albeit one that would take longer to complete, to conserve fuel. In April 2002, an unexpected blast of solar radiation knocked out some of its communications capabilities. When it arrives, more than four years late, it might be too low on fuel and too damaged to send back data on the atmosphere and topography of Mars.
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The launch is a milestone, but just one of many along the way. Landing historically is where the most risk is involved.
