ExoMars Trace Gas Orbiter Heads to Space

The launch of ESA's ExoMars Trace Gas Orbiter and Schiaparelli lander heralds a new phase of Mars exploration. 

An artist's conception of the Schiaparelli lander separating from the ExoMars Trace Gas Orbiter.
ESA / D. Ducros

A Russian Proton rocket launched from the Baikonur Cosmodrome earlier today with humanity's sole mission to Mars for 2016: the European Space Agency's ExoMars Trace Gas Orbiter.

The launch occurred at 9:31 Universal Time (5:31 a.m. EDT) and went off without a hitch. Next, the Proton rocket and its Briz (Breeze) M upper stage performed a series of looping elliptical passes and correction burns while still in Earth orbit before setting the spacecraft on a path to the Red Planet. (Remember, a malfunction at this stage is what doomed the Phobos-Grunt mission in 2011.)

Final separation of the ExoMars spacecraft occurred as planned 41 minutes 19 seconds after liftoff, and engineers expect to get first contact signalling a healthy spacecraft en route to Mars at 21:28 UT later today.

“It's a milestone that caps off several years of preparation for any complex mission — designing, building and testing ground systems, preparing the flight operations procedures and then finally an intensive period of planning,” says Paolo Ferri, ESA's head of missions operations, in a recent press release.

Tempting the "Galactic Ghoul"

The ExoMars Trace Gas Orbiter and Schiaparelli lander in the clean room on Earth. ESA-S. Corvaja

The optimal time for Mars-bound launches comes around about once every two years. The launch window for ExoMars ran from March 14th to 25th, a couple months before Mars reaches opposition on May 22nd. NASA's InSight lander was also set to make the journey to Mars during a similar window, but a sensor leak forced planners to delay the launch. NASA is now targeting a new launch date in May 2018.

ExoMars carries its own lander, dubbed Schiaparelli, slated for release from the orbiter after seven months of cruising to the Red Planet. Release is slated to occur on October 16th — four days before orbital insertion — and Schiaparelli will land three days later at Meridiani Planum, the same region being explored by NASA's long-lived Opportunity rover.

Schiaparelli is named after the famous 19th-century astronomer and Mars observer Giovanni Schiaparelli. Schiaparelli was actually born on this day in 1835.

The battery-powered Schiaparelli lander is only expected to last four Martian days (called sols) on the surface. A successful landing would represent a first for any space agency other than NASA's and the Soviet Union's Mars 3 (which stopped working seconds after its safe arrival); all other Russian attempts to land on Mars failed, as did the British Beagle 2 lander in 2003. In 2015, NASA's Mars Reconnaissance Orbiter photographed the ill-fated Beagle 2. Landing and operating on Mars is hard, and many in the space community joke that the "Great Galactic Ghoul" has it out for Mars-bound spacecraft.

(Learn more about the fates of spacecraft bound for the Martian surface in our FREE ebook: Mars Landings: Then & Now.)

The descent profile for the Schiaparelli lander. ESA/ATG Medialab

The Plans for ExoMars

After arriving in Martian orbit and delivering the Schiaparelli lander to the planet's surface, the ExoMars orbiter will execute a series of looping elliptical orbits. Science operations are scheduled to begin at the end of 2017. ESA also plans to use the ExoMars orbiter as a communications relay for its 2018 ExoMars rover, and the orbiter is designed to operate until 2022.

The primary objective of this mission, a collaboration between ESA and the Russian space agency Roscosmos, is to search out evidence for trace gases in the Martian atmosphere. One elusive mystery on Mars is the source of trace amounts of methane spotted there from Earth. The gas could be the result of fresh volcanic eruptions or current biological processes. ExoMars will also test key technologies required to land a rover on Mars in 2018.

The ExoMars Trace Gas Orbiter carries a Color and Stereo Surface Imaging System (CaSSIS), a Fine Resolution Epithermal Neutron Detector (FREND), the Nadir and Occultation for Mars Discovery (NOMAD) infrared and ultraviolet spectrometer, and the Atmospheric Chemistry Suite (ACS). CaSSIS will scout out potential landing sites for the 2018 ExoMars rover, while NOMAD and ACS will observe sunlight filtered through the Martian atmosphere when they pass through twilight twice per orbit.

Meanwhile, down on Mars, the Schiaparelli lander will employ the DREAMS (Dust Characterization, Risk Assessment, and Environment Analyzer on the Martian Surface) meteorological package to monitor conditions on the surface. Sensors on DREAMS were designed by the Finnish company Vaisala, which has a long history of designing weather detectors for use on both Earth and space. The Curiosity rover also uses similar Vaisala weather sensors.

The arrival of the ExoMars Trace Gas Orbiter will add to the growing orbital roll call around the Red Planet, including Mars Odyssey, Mars Express, MRO, Maven, and India's Mars Orbiter Mission. H. G. Wells' Martians may never have invaded Earth, but humanity's robotic explorers are now swiftly conquering the Red Planet.