ESA’s first Mars orbiter will provide an important helping hand when the second arrives at the Red Planet in October.
Following lift off in March, the ExoMars Trace Gas Orbiter (TGO) and the Schiaparelli lander are now enroute to Mars, with arrival set for 19 October.
Once orbiting Mars, TGO will begin analysing rare gases in the planet’s atmosphere, especially methane, which on Earth points to active geological or biological processes.
Meanwhile, Schiaparelli will demonstrate the technology needed to make a controlled landing.
But they have to arrive at the planet first, and that’s where the 13 year-old Mars Express will lend a crucial helping hand – or, rather, ear.
Separation, atmospheric entry, descent, landing
On 16 October, Schiaparelli will separate and, three days later, descend and land as TGO enters orbit.
On landing day, ESA’s Mars Express, which has been delivering spectacular science data since 2003, will record signals from Schiaparelli for mission control to confirm a safe arrival and later reconstruct its descent.
“This will use the Mars Express Melacom communication system, originally carried for communications with the Beagle 2 lander and NASA rovers,” says James Godfrey, Mars Express deputy spacecraft operations manager.
“This will enable Mars Express to detect and record critical Schiaparelli descent events, such as entry into the atmosphere, parachute deployment, heatshield release, touchdown and start of surface activities.”
The orbit of Mars Express was adjusted in February for it to be in the right part of the martian sky to hear the signals transmitted from the descending Schiaparelli.
ExoMars 2016 arriving at Mars
On 19 October, about 80 minutes before landing, Schiaparelli will wake up and a few minutes later begin transmitting a beacon signal.
Mars Express will already have pointed Melacom’s small antenna to the spot above the planet where Schiaparelli will appear, and will begin recording the beacon, turning to follow the descent path.
“Recording will continue through touchdown and the first 15 minutes of surface operation, after which Schiaparelli will switch off and Mars Express will stop recording,” says Simon Wood, Mars Express spacecraft operations engineer.
Then, Mars Express will turn its main antenna towards Earth and begin downloading data that contain the first in-situ confirmation from Mars of Schiaparelli’s arrival and landing.”
Melacom’s software was recently updated to be compatible with Schiaparelli’s transmitter. On 15 June, it will be tested while flying over NASA’s Curiosity rover, which will transmit a signal similar to Schiaparelli’s.