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Mars TGO mission heads for Red Planet on methane quest Mars TGO probe despatched on methane investigation
(about 7 hours later)
Europe and Russia have launched a joint mission to the Red Planet. A joint European and Russian space mission is heading to Mars.
The satellite, called the ExoMars Trace Gas Orbiter (TGO), lifted off from Baikonur in Kazakhstan at 09:31 GMT. Launched from Baikonur in Kazakhstan, the ExoMars Trace Gas Orbiter (TGO) will study methane and other rare gases in the Red Planet's atmosphere.
The probe will investigate whether the methane in the world's atmosphere is coming from a geological source or is being produced by microbes. Controllers have confirmed the probe has been ejected from the space tug that was tasked with hurling it away from Earth.
If all goes well, the two space powers expect to follow up this venture with a rover, to be assembled in the UK, which will drill into the surface. But they still need to receive a signal from the satellite itself which is due at 21:29 GMT.
That could launch in 2018, or, as seems increasingly likely, in 2020. This would give controllers some idea of the health status of the TGO. Early analysis has already established that the 4.3-tonne satellite was released on to the optimum path by the tug.
Exomars missions are go - finallyExomars missions are go - finally
Where on Mars do you look for life?Where on Mars do you look for life?
It takes several hours to put the satellite on the right trajectory to go to Mars. The European and Russian space agencies' mission began with the thunderous lift-off of a Proton rocket at 15:31 Baikonur time (09:31 GMT).
A series of engine burns by the Proton rocket's Breeze upper-stage are required to build up the velocity needed to break free of Earth's gravity. This vehicle put the TGO in a low-Earth orbit, from where the Breeze-M tug then began a series of engine burns to build up the speed needed to go to Mars.
By 13:30 GMT, it was confirmed that three of these firings had occurred, with one last effort scheduled for late in the evening on Monday. The cruise to the Red Planet is a seven-month, 500-million-km journey. And even when it arrives, the TGO will take the better part of a year to manoeuvre itself into just the right position around Mars. So, in reality, the satellite's observations will not start in earnest until late 2017.
The flight sequence has strained the nerves of space agency officials. There have been many anxious but excited conversations during the day here at the European Space Agency's mission operations centre in Darmstadt, Germany. But when they do, they will represent the first life-detection investigations made at Mars in more than 40 years.
For Russia especially, the Red Planet represents a destination of wretched fortune. The TGO's instruments can sense the smallest components in the air with remarkable fidelity.
It has previously launched 19 missions to the fourth planet from the Sun, and most of those have been outright failures. Of prime interest, of course, is methane, which exists at levels 1,000 times lower than on Earth. On our planet, the CH4 molecule is present in the parts per million by volume; on Mars, it is in the parts per billion.
Many could not get off the pad cleanly; others simply stalled above the Earth and fell back down; a few crashed and burned at Mars or sailed straight past. But in the harsh environment on Mars, this gas should be destroyed by sunlight relatively rapidly, over the course of a few hundred years.
Assuming everything works out this time, controllers in Darmstadt can expect a first signal from the TGO after it has been released on its way by the Breeze stage. So, the fact that a signal persists suggests the simple hydrocarbon is continually being replenished somehow.
This should come through at 21:28 GMT. It is then a seven-month cruise to Mars. An obvious explanation is that active geological processes are responsible. Ideas include something called serpentinisation, which yields methane at the end of a chain of reactions when water comes into contact with certain rock minerals.
Three days out from arrival, on 16 October, the satellite will eject a small landing module known as Schiaparelli. It is also possible that the methane seen on Mars today is actually an old store that was locked away in ice, perhaps billions of years ago, and occasionally pulses into the atmosphere today when that ice gets melted for some reason.
Once on the surface, on 19 October, its aim is to operate a few science instruments, but engineers are primarily interested to see how the module performs during the entry, descent and touchdown. But the notion that sub-surface microbes could additionally be making a contribution is not so fanciful, say scientists. After all, single-celled organisms are the main source of methane in Earth's atmosphere.
In particular, Schiaparelli will showcase a suite of technologies - radar, computers and their algorithms - that will be needed to put a later, British-built rover safely on the planet. The TGO satellite will fly around the Red Planet, analysing the chemical fingerprints of the gas to try to get some clues. One such line of evidence would come from the isotopic nature of the carbon element in methane. Life on Earth tends to favour a lighter version of this atom. The TGO will have the sensitivity to discern this kind of detail.
This second step in the joint European-Russian ExoMars project is supposed to leave Earth in 2018, although this is now looking increasingly doubtful because of funding and scheduling issues. Many connected with ExoMars are now talking about 2020 as being a more realistic launch date. But Dr Jorge Vago, the European Space Agency's project scientist on the mission, cautions that definitive answers will be hard to come by.
"I am not sure we will ever be in a position to have a smoking gun, and say 'for sure, it is this'. But little by little, as the mission progresses, we will get better at focusing our hypotheses and what the explanations might be."
Schiaparelli's demonstration landing on 19 OctoberSchiaparelli's demonstration landing on 19 October
None of this affects the TGO mission, however. Further lines of evidence should emerge when a second European-Russian mission - a British-assembled rover - launches in a few years' time.
After it has dropped off Schiaparelli, the satellite will spend the better part of a year manoeuvring itself into a 400km-high circular orbit above Mars. This will drill below the surface, and subject rock and dust samples to analyses designed to detect the chemistry practised by biological systems - either taking place in the present or having done so in the past.
From this vantage point, the orbiter's state-of-the-art instruments will then make a detailed inventory of Mars' atmospheric gases. But to get any answers, all the technology will have to be delivered safely to Mars and work - and for Russia in particular this is a high-pressure expectation.
Methane is the key interest. Previous observations - by satellite, Earth-based telescopes and America's Curiosity rover on the surface of the planet - found the hydrocarbon to be present in very low concentrations, at just a few parts per billion by volume. Most of its 19 previous Red Planet missions were outright failures. It is hoping for better fortune by teaming up with Europe.
That it is there at all is surprising. Ultraviolet light should remove the gas from the atmosphere within a few hundred years, which suggests it must be replenished somehow. One way the TGO plans to mitigate future risk is by dropping a demonstration lander on the surface in October.
One possible active source involves geological activity at depth, where water could be reacting with rock minerals to produce hydrogen, which is then further processed into methane. This module, known as Schiaparelli, will carry a number of scientific instruments, but its primary purpose is to test systems needed to get the rover down safely in 2019 or 2021, whichever date is chosen for that endeavour.
Another tantalising prospect is that the source is biological in origin. These critical landing systems include a radar, computers and their algorithms.
Most of the methane in Earth's atmosphere comes from microbes, like those in the stomachs of ruminants.
There are no cows on Mars, but simple organisms could conceivably be operating just below the surface of the planet.
The TGO's measurements should throw some light on these competing ideas.
Russia's torrid history of Mars missions
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmosJonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos