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Mars Express (ASPERA-3)

Mars Express (ASPERA-3) mission graphic

Mars Express

Phase: Operating

Launch Date: June 02, 2003

Mission Project Home Page -

Program(s):Discovery, Mars Exploration

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NASA is participating in a mission of the European Space Agency and the Italian Space Agency called Mars Express, which has been exploring the atmosphere and surface of Mars from polar orbit since arriving at the red planet on December 26, 2003.

The mission's main objective is to search for sub-surface water from orbit. Seven scientific instruments on the orbiting spacecraft have conducted rigorous investigations to help answer fundamental questions about the geology, atmosphere, surface environment, history of water, and potential for life on Mars. Examples of discoveries - still debated by scientists -- by Mars Express are evidence of recent glacial activity, explosive volcanism, and methane gas.

NASA's involvement with the mission includes joint development of a radar instrument called MARSIS - short for the Mars Advanced Radar for Subsurface and Ionospheric Sounding - with the Italian Space Agency. MARSIS has already provided information about features beneath the Martian surface, including buried impact craters, layered deposits, and hints of deep underground water ice.

MEX - Radargram

The upper image is a radargram from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), showing data from the subsurface of Mars in the ice-rich layered deposits that surround the south pole. The lower image shows the position of the ground track (white line) on a topographic map of the area based on Mars Orbiter Laser Altimeter data. The images are 1,250 kilometers (775 miles) wide.

Image Credit: NASA/JPL/ASI/ESA/Univ. of Rome/MOLA Science Team

NASA’s contribution to the mission is an energetic neutral atoms analyzer instrument is called ASPERA-3. The Analyzer of Space Plasmas and Energetic Atoms studies the interaction between the solar wind and the atmosphere of Mars, and attempt to find out what happened to the large amount of water that was once on Mars.

The Earth and Mars, like the other planets, swim deep inside a plasma of charged particles (ions and electrons) racing outward from the Sun called the solar wind. ASPERA will study how the solar wind interacts with the Martian atmosphere and thus throw light on the mechanisms by which water vapor and other gases could have escaped from Mars in the past. The instrument will use a technique known as energetic neutral atom imaging to visualize the charged and neutral gas environments around Mars.

NASA's involvement also includes coordination of radio relay systems to make sure that different spacecraft operate together; a hardware contribution to the energetic neutral atoms analyzer instrument; and backup tracking support from NASA's Deep Space Network during critical mission phases.

While addressing its science objectives, Mars Express will also provide relay communication services between the Earth and various landers deployed on the surface by other nations, thus forming a center piece of the international effort in Mars exploration.

Initially, Mars Express also carried a small lander called Beagle 2, named for the ship in which Charles Darwin set sail to explore unchartered areas of the Earth in 1831. The lander was lost on arrival in December, 2003.


This mission is part of the Mars Exploration Program.