Post by Taxigirl on Jan 25, 2004 9:35:38 GMT
Opportunity, the second of two Nasa rovers, has successfully landed on the Martian surface where it will search for signs of water on the planet.
The new rover touched down at 0505GMT, halfway around the red planet from where Spirit rover landed on 4 January.
Opportunity landed on a smooth, flat plain, in the highest altitude landing ever attempted by Nasa.
Spirit sent back striking colour photos of Mars but stopped working properly on Wednesday.
Light landing
But Nasa scientists now say they are making good progress on fixing Spirit.
"We resurrected one rover and we saw the birth of another. This was one heck of a critical milestone," Ed Weiler, associate administrator for space science at Nasa, told a news conference.
Nasa administrator Sean O'Keefe called the Mars exploration team "the best in the world", saying: "This is a truly remarkable achievement."
Mission controllers hugged each other and cheered as confirmation of the landing was beamed to Earth via a signal tone.
Fluctuating signal
The signal sent back to Earth suggested there were no faults with the rover.
California Governor Arnold Schwarzenegger appeared following confirmation of the successful landing to greet ground controllers.
The first pictures of Opportunity's landing site arrived at 0912 GMT, confirming the rover had retracted its airbags and deployed its solar arrays successfully.
A periodic fluctuation in the lander's signal first suggested that it rolled on the Martian surface for more than 20 minutes after landing.
But this was actually because Opportunity's antenna was pointing downwards and the signal was bouncing off the surface of Mars, scientists said.
Opportunity approached the Martian surface at a speed of 19,000 km/h (12,000 mph). It deployed a parachute to slow its descent and airbags to cushion its landing.
Rockets on the lander counteracted light gusts of wind during the descent, making for an exceptionally gentle landing on Mars.
It touched down with a force of between two to three Gs - an exceptionally gentle landing. The rover was designed to withstand a landing of up to 40 Gs.
Opportunity landed with one of its three side "petals" pointing down. This meant it needed to rotate itself to an upright position, something Spirit did not have to do as that rover landed with its base pointing down.
Dark grey landscape
The rover's landing site on Meridiani Planum, which is near the Martian equator, is thought to be dark grey, or black - rich in a mineral called grey haematite.
Scientists believe water may have once flowed there.
The two solar-powered landers have been sent to study the surface of Mars for three months. But Nasa now plans to extend this period of exploration.
Spirit was about to start grinding into a boulder on its 19th day on Mars when Nasa lost contact with the robotic vehicle.
Project manager Pete Theisinger said Spirit had now been upgraded from "critical" to "serious". The fault could now take days or weeks to put right.
Nasa will want to trace the source of Spirit's problems because it could have implications for the way Opportunity is deployed.
