Mars Odyssey was launched on April 7th, 2001 and entered Mars orbit on October 24th, 2001. Similar
to Mars Climate Orbiter, Mars Odyssey carried instruments for the measurement
of minerals, the location of deposits of water, and the measurement of
radiation on the Martian surface. The mission of Mars Odyssey is currently
ongoing and data returned from it is being used to locate sites for future
landers.
Mars Express
Mars Express is the first successful robotic probe to Mars
launched and operated by the European Space Agency. It launched in June of 2003
and arrived in Mars orbit on December
25th, 2003. Mars Express is designed to search for
subsurface water, as well as to analyze Mars’ atmosphere, structure, geology
and composition. Mars Express also
carried a British built lander, called the Beagle 2, which crashed when
attempting to land on the Martian surface. Mars Express also carries a
communications relay for landers, The mission of Mars Express is ongoing.
Mars Exploration Rovers (Spirit and Opportunity)
Mars Exploration Rover A, later named Spirit, was launched
on June 10, 2003 and
arrived on Mars in the Gusev Crater on January
4th, 2004. Mars Exploration Rover B, later named Opportunity,
was launched on July 7th,
2003 and landed in the Terra Meridiani on January 25th, 2004. Both vehicles
landed with the aid of an aeroshell, parachutes, retro rockets, and air bags
previously used by Mars Pathfinder. Both rovers are essentially robotic
geologists, with instruments designed to study rocks and soil and to uncover
evidence of ancient water activity. The rovers also have cameras for determining
the mineralogy, texture, and structure of the local terrain. The rovers are
capable of moving about a hundred meters a day along the Martian surface.
Spirit and Opportunity are bigger and faster, with more
range and more instruments than did Mars Sojourner. Their mission, over a year after landing on
the Martian surface, is ongoing.