The effort is part of the society's Red Rover Goes to Mars Project to offer hands-on experience to students interested in space science. The "student astronaut" team consists of 16 teenagers who won their berths on the project through a worldwide essay contest held by the Planetary Society and LEGO.

Each week, two students will sit in the Mars Exploration Rover control room at NASA's Jet Propulsion Laboratory (JPL) and study mission data and images as they arrive. Students record their efforts online in daily journals, summarizing their activities during their week at JPL.

On-duty Student Astronauts: Shih-Han Chen, 16,of Taiwan and the U.K, and Abigail Fraeman, 16, of Canada and the U.S. Chen and Fraeman have arrived at JPL for their Jan. 16-27 tour, though their journals have yet to be updated.

The previous team, Susini de Silva, 17, of Sri Lanka and Tomás Kogan, 13, of Spain, completed their shift at JPL on Jan. 18 and were in the mission operations room when Spirit rolled off its landing platform and onto the Martian surface.

"I'm still so very excited about this and I feel Tomás and I are very much lucky to be here today," Susini wrote in a Jan. 15 journal entry - the day Spirit rolled completely onto Mars. The mission, so far, has been an unbelievable success, and the rolloff one its most important points, she added.

"I hope everyday goes as well as today for Spirit and Opportunity, which is going to land in just a few days," Tomas said in his Jan. 15 entry.

Both Susini and Tomás, and indeed all student astronauts and Mars mission scientists, have had to accustom themselves to Spirit's odd hours. The students typically arrive at JPL around midnight and work until early the next morning. As an example, Susini wrote, the mission team recently passed what is called the 12-hour separation point, a time when it was 5 a.m. at JPL, but 5 p.m. at Gusev Crater on Mars. The schedule has thrown off their sleep and eating schedules.

During their time at JPL, Susini and Tomás have made daily calibrations of the MarsDial, a sundial aboard Spirit that allows researchers to determine the local time on Mars, and posted images of the sundial online. They have also helped JPL scientists identify carbonate minerals on Mars. Carbonate minerals are important because they can result from an interaction between carbon dioxide, which is plentiful on Mars, and water.

In addition to their scientific work, the student astronauts were also interviewed by local newspapers and the national radio program Voice of America and recently appeared with fellow students Abigail Fraeman and Shih-Han Chen in local television programs for children. The Planetary Society's first student team, 15-year-old Courtney Dressing of the U.S. and Brazil's Rafael Morozowski, 16, completed their run at JPL on Jan. 10, the seventh Martian day of Spirit's mission.

The Planetary Society is a non-profit space advocacy organization based in Pasadena, California. Founded in 1980, the society consists of more than 100,000 members from over 140 countries. Individuals interested in joining the organization can do so here.