With arrival at Mars set for October 19, ESA mission control in Darmstadt, Germany is busy making last minute adjustments for the Exomars 2016 mission. One key milestone completed last week was the uploading of final instructions for the computer aboard the Schiaparelli entry, descent and landing demonstrator spacecraft. The new commands will tell Schiaparelli when to separate from the Trace Gas Orbiter mothership, then guide the unmanned lander during its descent and touchdown on the surface of Mars.
ESA says the commands were sent in two phases. The first was transmitted on October 3 and activated Schiaparelli's hibernation wake up timers and set the surface science events. The second, sent on October 7, covered mission command sequences for entry and landing.
The final command uploads are a key step in preparation for landing because the Schiaparelli probe works on a series of time-tagged pre-programmed commands that are dependent on determining when the sequence should start.
The Schiaparelli module, which is designed to test systems for the ExoMars 2020 rover, has remained docked and dormant with the Trace Gas Orbiter since the mission launched on March 14. Shortly before the mothership makes an engine burn that will send it into Mars orbit, Schiaparelli will disengage and plunge into the Martian atmosphere for a landing scheduled for October 19 at 14:48:11 GMT (4:48:11 pm CEST).
During the landing maneuvers, the sequence commands will ensure that Schiaparelli is on the right course and at the right attitude for its hypersonic entry into the Martian atmosphere. Once it's slowed down sufficiently, a parachute will deploy and the computer will jettison the probe's protective heat shield and aeroshell. Three sets of hydrazine thrusters will then fire and slow the descent even more as radar keeps track of the altitude. At a height of just 2 meters, the engines will cut out and the spacecraft will land.
Schiaparelli is programmed to carry out science observations if it survives impact. It will remain active for six hours a day to conserve power, and ESA hopes it will have enough battery power to operate for at least two days. In addition, Schiaparelli is programmed to use ESA and NASA's Mars orbiters to relay data back to Earth for analysis.
Watch a visualisation of the Schiaparelli module landing on Mars in the video below:
Video Credit: ESA/ATG medialab