PARIS / AFP
Europe and Russia are set to launch an unmanned spacecraft on Monday to smell Marsâ€™ atmosphere for gassy evidence that life once existed on the Red Planet, or may do so still.
ExoMars 2016, the first of a two-phase Mars exploration, will see an orbiter hoisted from Kazakhstan at 0931 GMT Monday on a Russian Proton rocket.
With its suite of high-tech instruments, the Trace Gas Orbiter or TGO, should arrive at the Red Planet on October 19 after a journey of 496 million kilometres (308 million miles).
Its main mission to photograph the Red Planet and analyse its air, the TGO will also piggyback a Mars lander dubbed Schiaparelli.
â€œRocket rolloutâ€”our #ExoMars 2016 mission is at the launch pad!â€ the European Space Agency (ESA) tweeted on Friday. ExoMars is a two-step collaboration between ESA and Russiaâ€™s Roscosmos space agency. The second phase, a Mars rover due for launch in 2018, seems likely to be delayed over money worries.
But the first phase is going ahead as planned, and with high expectations: â€œDetermining whether Mars is â€˜aliveâ€™ todayâ€, according to an ESA document.
A key goal is to analyse methane, a gas which on Earth is created in large part by living microbes, and traces of which were observed by previous Mars missions.
â€œTGO will be like a big nose in space,â€ according to Jorge Vago, ExoMars project scientist.
Methane, the ESA said, is normally destroyed by ultraviolet radiation within a few hundred years, which implied that in Marsâ€™ case â€œit must still be produced today.â€
The question is: By what?
Methane can either be generated in a biological process, such as microbes decomposing organic matter, or geological ones involving chemical processes in hot liquid water under the surface.
TGO will analyse Marsâ€™ methane in more detail than any previous mission, said ESA, to try and determine its likely origin.
Anybody out there?
Another key element of the ExoMars 2016 mission is Schiaparelli, named after a 19th century Italian astronomer whose discovery of â€œcanalsâ€ on Mars caused people to believe, for a while, that there was intelligent life on our neighbouring planet. Schiaparelli is a â€œdemonstratorâ€ module to test heat shields and parachutes in preparation for a subsequent rover landing on Mars, a feat ESA said â€œremains a significant challengeâ€.
During its few live days on the surface of Mars, Schiaparelli will also measure atmospheric particles, wind speed and temperatures.The TGOâ€™s main science mission is scheduled to last until December 2017, but it has enough fuel to continue operations for years after, if all goes well. As for the next phase, ESA director general Jan Woerner has mooted a possible two-year delay, saying in January: â€œWe need some more moneyâ€ due to cost increases.
The rover has been designed to drill up to two metres into the Red Planet in search of organic matter, a key indicator of life past or present.
Scientists widely accept that liquid water, an essential ingredient for life, once flowed on Mars. Researchers unveiled â€œthe strongest evidence yetâ€ the planet may still host water in the form of super-salty streaks of brine.
Todayâ€™s Martian surface is considered too dry and radiation-blasted for living organisms to survive, but conditions would have been much more comfortableâ€”warmer and wetterâ€”some 3.5 billion years ago.
â€œEstablishing whether life ever existed on Mars, even at a microbial level, remains one of the outstanding scientific questions of our time,â€ said ESA, â€œand one that lies at the heart of the ExoMars programmeâ€.
The mission derives its name from the scientific term for the search for life beyond Earthâ€”exobiology.