August 1, 2014

Demonstrator

The first mission within the ESA - Roscosmos ExoMars Programme, scheduled to arrive at Mars in 2016, consists of an Orbiter plus an Entry, Descent and Landing Demonstrator Module (EDM), called Schiaparelli.

The Orbiter and EDM will be launched together on a Proton rocket and will fly to Mars in a mated configuration. By taking advantage of a direct interplanetary trajectory to Mars the cruise phase can be limited to about 9 months. Upon arrival at Mars the EDM will be ejected on a hyperbolic entry trajectory towards the Red Planet.

The 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.

After entering the Martian atmosphere the module will deploy a parachute and will complete its landing by using a closed-loop Guidance, Navigation and Control system based on a Radar Doppler Altimeter sensor and on-board Inertial Measurement Units. The latter will guide a liquid propulsion system which will produce a semi-soft touchdown on the surface of Mars by the actuation of clusters of thrusters to be operated in pulsed on-off mode.

 ESA  ESA  ESA
Schiaparelli Entry, Descent and Landing phases. Credits: ESA

The EDM is expected to survive on the surface of Mars for a short time (about 8 sols) 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 surface science.

 TAS-I, DREAMS team, ESA
Schiaparelli surface scientific payload - Credits: TAS-I, DREAMS team, ESA

The EDM surface payload, named DREAMS (Dust Characterisation, Risk Assessment, and Environment Analyser on the Martian Surface), consists of a suite of sensors to measure the wind speed and direction (MetWind), humidity (DREAMS-H), pressure (DREAMS-P), surface temperature (MarsTem), the transparency of the atmosphere (Solar Irradiance Sensor, SIS), and the electric fields on the planet's surface (Atmospheric Radiation and Electricity Sensor; MicroARES).