Saturday, April 16, 2016

ExoMars Mission

ExoMars, or Exobiology on Mars, is a mission jointly run by the European Space Agency (ESA) and the Russian Federal Space Agency (Roscosmos) to investigate possible traces of life on the planet Mars. The mission includes two launches: one in 2016 and one in 2018, with the first delivering an orbiter and a lander to Mars and the second the ExoMars rover.

The first launch took place on March 14, 2016 in Kazakhstan using a Russian-built launch vehicle. Both the Trace Gas Orbiter (TGO) and the Entry, Descent, and Landing Demonstrator Module (EDM) arrived in the Martian system in October 2016.

On October 16, 2016, the two components separated as planned, with the TGO performing a maneuver shortly after to remain in orbit. The primary mission of the TGO, as the name suggests, was to refine our measurements of the scarcer components of the Martian atmosphere, including methane and water vapor. From an orbit about 250 miles above the surface of the red planet, the orbiter was positioned to obtain information orders of magnitude more accurate than any previous results. Methane in particular is generated by specific geological and organic processes. While the Trace Gas Orbiter could not identify the cause of gaseous emissions by itself, it did have the capability to pinpoint the sources geographically, aiding in the selection of the ExoMars rover landing site. The orbiter itself was constructed by the ESA while the Russian agency contributed several of its instruments.

Meanwhile the EDM lander (also called Schiaparelli after the Italian astronomer Giovanni Schiaparelli) was built to demonstrate crucial techniques for landing on the Martian surface shortly after the first spacecraft arrives at Mars. Weighing over 1300 pounds, the lander required a controlled landing to reach the Martian surface safely, just like the Curiosity rover.



The probe used a heat shield and parachutes to slow its descent and a liquid propulsion braking system to control its final touchdown on Mars. However, an error in the autonomous landing system led to the parachutes being deployed too early, when the lander was still several kilometers above the surface. As a result, the lander was torn to pieces, and did not function after impact. These components, along with the lander itself, were captured in an image on October 25 by NASA's Mars Reconnaissance Orbiter. While Schiaparelli was unable to survive landing, it still provided valuable data to guide future missions.

The second launch will occur sometime in the latter half of 2018, carrying the European-built ExoMars rover and a surface platform on which it will land, contributed by Roscosmos. The spacecraft will arrive at Mars in early 2019 at a landing site chosen with help from the 2016 mission's data. The same technology demonstrated in the first landing will allow the second module to perform a soft touchdown on the surface of Mars. After landing, the surface platform will deploy ramps, off of which the rover will exit to begin its exploration of the surface.

The rover's mission will last at least six months. Its primary mission will be to search for organic substances on the Martian surface. Since the harsh conditions of the surface may have obliterated traces of chemicals, the ExoMars rover will have the ability to bore holes as deep as two meters to obtain better preserved samples. After collecting samples, the rover will transfer them to its onboard laboratory for chemical analysis. With its careful site selection and dedicated exobiology instruments, the ExoMars mission has perhaps the best opportunity yet of discovering definitive biosignatures on Mars. It also would accomplish the technological objective of honing the ability to make soft, precision landings on the red planet. Finally, the mission paves the way for the holy grail of Martian exploration: returning a sample from the red planet back to Earth. Sources: http://exploration.esa.int/mars/, http://exploration.esa.int/mars/47852-entry-descent-and-landing-demonstrator-module/, http://exploration.esa.int/mars/58557-schiaparelli-crash-site-in-colour/

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