ExoMars Orbiter and EDM Mission (2016)

The first mission of the ExoMars programme, scheduled to arrive at Mars in 2016, consists of a Trace Gas Orbiter plus an Entry, Descent and Landing Demonstrator Module (EDM). The main objectives of this mission are to search for evidence of methane and other trace atmospheric gases that could be signatures of active biological or geological processes and to test key technologies in preparation for ESA's contribution to subsequent missions to Mars.

The Orbiter and EDM will be launched together in January 2016 on a Proton rocket and will fly to Mars in a mated configuration. By taking advantage of the positioning of Earth and Mars the cruise phase can be limited to about 9 months. Three days before reaching the atmosphere of Mars, the EDM will be ejected from the Orbiter towards the Red Planet. The EDM capsule will then coast towards its destination, entering the Martian atmosphere and landing on the surface of the planet. From its coasting to Mars till its landing, the EDM will communicate with the Orbiter. Once on the surface, the communications of the EDM will be supported from a NASA Relay Orbiter. The ExoMars Orbiter will be inserted into an elliptical orbit around Mars and then sweep through the atmosphere to finally settle into a circular, ~ 400-km altitude orbit ready to conduct its scientific mission.

ExoMars 2016 Mission - Trace Gas Orbiter and Entry, Descent and Landing Demonstrator Module. Credit: ESA-AOES Medialab

Trace Gas Orbiter - Searching for signature gases in the Martian atmosphere

The Orbiter spacecraft is designed by ESA, while Roscosmos provides the launch vehicle. A scientific payload with instruments from Russia and Europe will be accommodated on the Orbiter to achieve its scientific objectives. The ExoMars Orbiter will perform detailed, remote observations of the Martian atmosphere, searching for evidence of gases of possible biological importance, such as methane and its degradation products. The instruments onboard the Orbiter will carry out a variety of measurements to investigate the location and nature of sources that produce these gases. The scientific mission is expected to begin in mid 2017 for a period of at least one Martian year (687 Earth days). The Trace Gas Orbiter will also serve as a data relay asset for the 2018 rover mission of the ExoMars programme and until the end of 2022.

Entry, Descent and Landing Demonstrator Module – Testing critical technology for future missions

The ExoMars Entry, Descent and Landing Demonstrator Module will provide Europe with the technology for landing on the surface of Mars with a controlled landing orientation and touchdown velocity. The design of the EDM maximises the use of technologies already in development within the ExoMars programme. These technologies include: special material for thermal protection, a parachute system, a radar Doppler altimeter system, and a final braking system controlled by liquid propulsion.

The EDM is expected to survive on the surface of Mars for a short time by using the excess energy capacity of its batteries. The science possibilities of the EDM are limited by the absence of long term power and the fixed amount of space and resources that can be accommodated within the module; however, a set of scientific sensors will be included to perform limited, but useful, surface science.

Keeping in touch far from home

After launch and throughout the cruise phase, the spacecraft unit made up of the Orbiter and the EDM is operated by ESA through the space communications network of ESA's European Space Operations Centre (ESOC).

After separation, the Orbiter will monitor the UHF transmission from the EDM from its coasting to Mars till its landing. A NASA Relay Orbiter will act as a data relay for the EDM during its surface operations. Furthermore, ground-based communication arrays will also track the UHF signal during the entry, descent and landing phases.

ESA will be in full control of the Orbiter during all phases of its mission, including insertion into Mars orbit, orbit control, aerobraking, science operations and Mars communications operations.