Opportunity is set to land at 12:05 a.m. EST Jan. 25.
The flight team for NASA's Spirit received data from the rover for 20 minutes in a communication session early this morning.
"The spacecraft sent limited data in a proper response to a ground command, and we're planning for commanding further communication sessions later today," said Mars Exploration Rover Project Manager Pete Theisinger at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
Flight-team engineers were encouraged this morning when Spirit sent a simple radio signal acknowledging that the rover had received a transmission from Earth. But, the team is still trying to diagnose the cause of earlier communications difficulties that have prevented any data being returned from Spirit since early Wednesday.
NASA's Spirit rover has successfully driven to its first target on Mars, a football-sized rock that scientists have dubbed Adirondack.
With barely a week before reaching Mars, NASA's Opportunity spacecraft adjusted its trajectory, or flight path, today for the first time in four months.
For the first time, Spirit has reached out with its versatile robotic arm and examined a patch of fine-grained martian soil with a microscope at the end of the arm.
NASA's Spirit rover has left its lander and is ready to start exploring the red planet.
Spirit Gets a Travel Itinerary
The first 360-degree color view from NASA's Mars Exploration Rover Spirit presents a range of tempting targets from rocks nearby to hills on the horizon.
Spirit now has its arm and all six wheels free, and only a single cable must be cut before it can turn and roll off its lander onto the soil of Mars.
The engineers and scientists for NASA's Spirit are eager to get the rover off its lander and out exploring the terrain that Spirit's pictures are revealing, but caution comes first.
A color mosaic from Spirit is the highest-resolution picture ever sent from Mars, more than three times as detailed as images from Mars Pathfinder in 1997.
Thanks to the Internet, NASA can bring Mars into your living room, to a local Internet cafe, or anywhere else with access to the World Wide Web.
A shallow depression in the ground near the landing site -- described as "a window into the interior of Mars" -- may become an early destination for NASA's Spirit rover.
NASA's Spirit Rover is starting to examine its new surroundings.
A traveling robotic geologist from NASA has landed on Mars.
Administrator O'Keefe salutes "this amazing feat," calling it "a tribute to the dedication to the many men and women throughout NASA and our many partners."