The ExoMars mission contains two scientific instruments that are designed to explore the methane mystery that shrouds our Red neighbour. The Trace Gas Orbiter and the Schiaparelli Lander comprise the first leg of the ExoMars Mission launched earlier this year. This article attempts to simplify the science and technology behind the mission.
Trace Gas Orbiter
The methane traces on Mars can be biological or geological in nature. The concentration of methane in the Martian atmosphere varies with time and location. These observations, however, have been made from observatories on Earth. The purpose of the Orbiter’s mission is not just to examine the methane traces in Mars’ atmosphere, but to examine its overall atmosphere which contains traces of water vapour, nitrogen oxides and acetylene as well. The Orbiter serves as a transportation for a scientific payload and the Schiaparelli Lander, which is an Entry, Descent and landing demonstrator Module (EDM). The Orbiter will remain in orbit for the second leg of the mission which will take place in 2020. This will involve sending the ExoMars Rover. The Orbiter will serve the purp=ose of transmitting data received from the Rover.
The TGO will also examine the atmosphere of Mars for the duration of the Mission. The Orbiter is equipped with a suite of scientific instruments, three times more sensitive than the previous instruments, so as to measure the trace gases. They include the following
- ACS and NOMAD- The Atmospheric Chemistry Suite and the Nadir and Occultation for MArs Discovery accompany each other. Their functions involve the identification of atmospheric components using infrared and sometimes UV spectrometers.
- CaSSIS- Colour and Stereo Surface Imaging System is a hi-res camera that allows the Orbiter to gather visual data that will correspond with the data provided about trace gases by ACS and NOMAD.
- FREND- The Fine Resolution Epithermal Neutron Detector was built to detect hydrogen under the surface in order to reveal water-ice near the surface.
The Schiaparelli Lander will be deployed by the Orbiter. The most important data from the Lander will be transmitted to Earth by the Orbiter.
On the surface, the DREAMS (Dust Characterisation, Risk Assessment, and Environment Analyser on the Martian Surface) package comes into play. It consists of a suite of sensors to measure the wind speed and direction (MetWind), humidity (DREAMS-H), pressure (DREAMS-P), atmospheric temperature close to the surface (MarsTem), the transparency of the atmosphere (Solar Irradiance Sensor, SIS), and atmospheric electrification (Atmospheric Radiation and Electricity Sensor; MicroARES)
The instrument AMELIA (Atmospheric Mars Entry and Landing Investigation and Analysis) will take atmospheric measurements during entry and descent of the Lander. This will give us key insight into the Martian atmosphere and help us improve the models based on it. The Lander is also equipped with a Descent Camera (DECA).