Mars Express

Just before midnight local time on 2 June 2003, a Soyuz-FG rose from Baikonur Cosmodrome carrying something Europe had never sent anywhere: a spacecraft bound for another planet. Mars Express was assembled in record time to catch an extraordinary window, the summer Mars swung closer to Earth than it had in some 60,000 years. ESA had built the orbiter fast and lean, borrowing heavily from its Rosetta comet chaser designs, and the name 'Express' was a quiet boast about both the rapid build and the short cruise ahead.

Tucked aboard the 1,120-kilogram orbiter rode a British hitchhiker with a famous name: Beagle 2, a lander christened after Darwin's ship, with a nine-note call sign composed by the band Blur and a camera calibration target painted by Damien Hirst. Released on 19 December 2003, Beagle 2 was meant to announce its Christmas Day landing with that little tune. The call never came. That same day, Mars Express fired its main engine and slipped flawlessly into orbit, leaving Europe with a triumph and a heartbreak in the space of a single morning.

The orbiter then got to work and never really stopped. Its camera mapped the planet in stereo and colour, its spectrometers traced water and minerals, and its MARSIS radar, deployed cautiously in 2005 after fears its long booms might swing back and strike the spacecraft, peered kilometres beneath the surface. In 2018, MARSIS data revealed evidence of a body of salty liquid water buried about 1.5 kilometres under the south polar ice. Beagle 2's fate was finally solved in January 2015, when NASA's Mars Reconnaissance Orbiter photographed it sitting intact on Isidis Planitia, its solar panels only partially unfurled. It had landed, and come agonisingly close to working.

More than two decades later, Mars Express is still flying, one of the longest-lived planetary missions in history and ESA's elder statesman at Mars. It has watched seasons turn and dust storms swell, studied the moon Phobos in unprecedented detail, and handed its findings on to every Mars mission that followed. For an agency that had never left Earth's neighbourhood before 2003, this is the mission that made Europe an interplanetary power.