Next stop, Mars!
Two robotic spacecraft began a seven-month journey to the Red Planet today, blasting off together atop a Russian Proton-M rocket from Baikonur Cosmodrome in Kazakhstan at 5:31 a.m. EDT (3:31 p.m. local Kazakhstan time).
The spacecraft — the Trace Gas Orbiter and a lander called Schiaparelli — constitute the first part of the two-phase ExoMars program, a European-Russian project to hunt for signs of life on the Red Planet. The second phase will launch a deep-drilling rover in 2018, if current schedules hold.
ExoMars represents a significant broadening of the scientific research effort at Mars, which has been dominated by NASA for the past two decades. For example, the European Space Agency (ESA) mounted just one Red Planet mission prior to ExoMars — Mars Express, which launched in 2003 — and Russia has not yet achieved any interplanetary successes (though the same cannot be said of its predecessor nation, the Soviet Union). If all goes according to plan, TGO and Schiaparelli will separate from each other on Oct. 16, as the duo are approaching Mars.
The 8,220-pound TGO will enter orbit around the Red Planet on Oct. 19, then eventually work its way to a circular orbit with an altitude of about 250 miles. From this vantage point, the spacecraft will study the Martian surface and atmosphere using four different science instruments during a five-year mission that's expected to begin in December 2017.
TGO's chief task is to hunt for methane and its degradation products in Mars' air. The vast majority of methane in Earth's atmosphere is produced by microbes and other living organisms, so the gas is viewed as a possible sign of Red Planet life, if any exists.
However, geological processes can also generate methane, so a detection of the gas is not a slam dunk for life. Indeed, NASA's Mars rover Curiosity detected a 10-fold jump in methane levels in late 2013 and early 2014, but mission scientists still aren't sure what caused it.
TGO will do other jobs as well. For example, the photos it takes will help the ExoMars team choose a landing spot for the 2018 rover. And the solar-powered orbiter will serve as a communications link between that rover and Earth.
The orbiter's "instruments will also map the subsurface hydrogen to a depth of a meter , with improved spatial resolution compared with previous measurements," ESA officials wrote in a description of TGO. "This could reveal deposits of water ice hidden just below the surface, which, along with locations identified as sources of the trace gases, could influence the choice of landing sites of future missions."