Europe launches its first voyage to another planet, Mars. The European Space Agency's Mars Express probe launches from the Baikonur space center in Kazakhstan.

Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide atmosphere. At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from −153 to 20 °C and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, frost, larger polar regions of permafrost and ice caps, but no liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. It is half as wide as Earth or twice the Moon, with a diameter of 6,779 km (4,212 mi), and has a surface area the size of all the dry land of Earth.

The European Space Agency (ESA) is a 23-member international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 in the context of European integration. Its 2025 annual budget was €7.7 billion.

Mars Express is a space exploration mission by the European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA.

Baikonur is a city in Kazakhstan on the northern bank of the Syr Darya river. It is currently leased and administered by the Russian Federation as an enclave until 2050. It was constructed to serve the Baikonur Cosmodrome with administrative offices and employee housing. During the Soviet period, the town was known as Leninsk, and was sometimes referred to as Zvezdograd. It was officially renamed Baikonur by Russian president Boris Yeltsin on December 20, 1995.