The Columbia was lost on re-entry into the Earth's atmosphere on Feb. 1, 2003. Spirit successfully landed on Mars Jan. 3. It will spend the next three months exploring the barren landscape to determine if Mars was ever watery and suitable to sustain life.

"During this time of great joy for NASA, the Mars Exploration Rover team and the entire NASA family paused to remember our lost colleagues from the Columbia mission. To venture into space, into the unknown, is a calling heard by the bravest, most dedicated individuals," NASA Administrator Sean O'Keefe said in a written statement.

O'Keefe also announced plans to name the landing site of the Mars Spirit rover in honor of the Columbia crew. The area in the vast flatland of the Gusev Crater where Spirit landed this weekend will be called the Columbia Memorial Station.

The disc-shaped plaque was fitted to Spirit's antenna a few months before the craft was readied for booster liftoff from Cape Canaveral, Florida in June of last year.

Spirit's twin, Opportunity, will reach Mars on Jan. 25 to begin a similar examination of a site on the opposite side of the planet.

Since its historic landing, Spirit has been sending extraordinary images of its new surroundings on the red planet over the past few days. Among them, an image of the memorial plaque.

NASA continues to target the period of Sept. 12 to Oct. 4 -- give or take a few days -- as to when the shuttle fleet returns to flight status and a mission to the International Space Station will be flown.