Part of humanity's sixty-year campaign to explore Mars. See the full timeline of orbiters, landers, and rovers on the exploration overview, or explore the science these missions revealed.

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ESA orbiter

Mars Express

Status: Active · Launch: June 2, 2003 · Arrived: December 25, 2003
Europe's first Mars mission. Its MARSIS radar detected evidence of liquid water beneath the south polar ice cap.

Mars Express was Europe's first mission to another planet, and it has proven to be one of the most enduring. Launched by the European Space Agency in June 2003, the orbiter reached Mars that December and has been studying the planet ever since, making it one of the longest-serving spacecraft in orbit around Mars.

The mission has delivered a steady stream of major discoveries. Its instruments detected clays and other minerals that only form in the presence of water, strengthening the case for a wetter ancient Mars. Its radar sounder probed beneath the surface and the polar caps, and produced tantalizing evidence interpreted by some scientists as pointing to bodies of liquid water buried beneath the south polar ice — a finding that remains debated but that reshaped the conversation about present-day water on Mars.

Mars Express also carries a high-resolution stereo camera that has mapped the planet's surface in vivid three-dimensional detail, producing some of the most striking images of Martian canyons, volcanoes, and ancient river valleys ever captured. The mission originally carried a small British lander called Beagle 2, which reached the surface but failed to fully deploy and was lost. Despite that early setback, the orbiter's long and productive career has made Mars Express a cornerstone of European planetary science and a lasting partner to NASA's fleet at Mars.

Key Achievements

First ESA planetary mission
Detected potential liquid water under south pole
Mapped Mars surface in stereo 3D

Frequently Asked Questions

What is Mars Express?

Mars Express is the European Space Agency's first mission to another planet, an orbiter launched in 2003 that has studied Mars for two decades, making it one of the longest-serving spacecraft at the planet.

What has Mars Express discovered?

It has detected water-formed minerals, mapped the surface in high-resolution 3D, and produced debated radar evidence interpreted by some as liquid water beneath the south polar ice cap.

Did Mars Express carry a lander?

Yes. It carried the British Beagle 2 lander, which reached the surface in 2003 but failed to fully deploy and was lost, though the orbiter itself has had a long, successful career.