On March 14, a Russian Proton Rocket launched from Baikonur, Kazakhstan. Around half a day later, anxious mission controllers, scientists, and space fans got confirmation that the package it had carried was healthy, and on its way to Mars.
The payload is the first of two missions to be launched by the European Space Agency (ESA) and its Russian equivalent, Roscosmos, as a part of the ExoMars program. This project, which is short for “Exobiology on Mars,” is designed to look for traces of life on our near neighbour using a series of 4 probes. What launched this month were the first two probes: an orbiter named the Trace Gas Orbiter (TGO), and a lander named Schiaparelli that will piggy-back on the TGO until separation 900 000 km away from Mars.
The TGO will go into orbit around Mars in October of this year. It will start out on a very elliptical orbit and will spend about a year passing through Mars’ thin atmosphere to reduce speed and circularize its orbit. Once it settles into a circular 400 km orbit, it will do as the name suggests: analyse trace gases found in Mars’ atmosphere, particularly methane, and look for their origin. To do this, the TGO has two spectrometers that will observe the sun through Mars’ atmosphere twice per orbit (at sunrise and sunset), looking for the faint effect that trace gases in the parts-per-billion range have on the light.
In addition to observing which gases are present, the TGO will also attempt to diagnose their source—particularly for methane. Methane has a relatively short life span on Mars, on the order of centuries, which means it must have a geological or, perhaps, biological origin. NASA’s Curiosity rover and ESA’s Mars Express orbiter have both detected methane, but were not sensitive enough to thoroughly investigate, hence the launch of TGO. Two likely sources for methane on Mars are volcanoes and underground water-ice, so the TGO has instruments to image volcanoes and detect the ice.
The Schiaparelli lander is a test bed for future ESA Mars missions, including the second half of ExoMars. It will, for instance, prove the technology used during its entry into the Martian atmosphere, descent, and landing. Once landed, it will have only a short time of activity. It will perform some very interesting science such as measuring the electrical fields at the surface of the planet. According to ESA’s website, this will be the first time this measurement has been taken, and “…combined with measurements of the concentration of atmospheric dust, will provide new insights into the role of electric forces on dust lifting—the trigger for dust storms.”
Schiaparelli gets its name from 19th century Italian astronomer Giovanni Schiaparelli, an astronomer who studied the surface of Mars through his telescope. His observations of thin lines on the planet’s surface, which he called “canali,” led to theories that Martians were digging large canals to look for water in their planet’s interior. These lines were later shown to be an optical illusion, but Schiaparelli remains important for having mapped Mars’ surface. The name also fits because ExoMars’ largest European contributor is Italy.
The second half of the ExoMars Program will launch in 2018. This mission will contain a lander based on the Schiaparelli landing technology. Upon landing, the package will split in two, with a rover known as the ExoMars Rover emerging from the stationary ExoMars 2018 surface platform. The surface platform will make a number of readings of its local area over time to observe seasonal and other changes. It will also study the internal structure of Mars and changes in its angular velocity using Doppler frequency shifts of signals from Earth. The rover will set out in search of signs of life, potentially retrieving sub-surface samples from up to 2 metres underground.
The TGO and Schiaparelli are both critical first stages to the ExoMars project. Schiaparelli’s landing will inform the design of the 2018 mission. The ice and methane-emissions data found by TGO will be used to decide on an appropriately interesting landing site for the 2018 mission. The TGO will then act as an intermediary between the 2018 landers and Earth. In addition, the TGO is outfitted with a receiver that will allow it to communicate with NASA rovers currently on Mars, increasing their ability to relay data to Earth.
The launch of this first part of the ExoMars mission went off spectacularly. Hopefully both existing probes, and the 2018 probes, will function perfectly so that the search for life on Mars can be pushed well past its current extent.
Leave a Reply