the planets today logo

We use cookies. By browsing our site you agree to our use of cookies. OK, Got it

Video version of flight path. Your browser does not support the required version of Adobe Flash Player.

Spacecraft Mission Pages
Mariner 2 Pioneer & Voyager Voyager Galileo Cassini-Huygens Rosetta
Messenger Dawn New Horizons Juno OSIRIS-REx ExoMars

Where is the ExoMars TGO Spacecraft right now?

The app above shows the trajectory of the ExoMars TGO Spacecraft and where it is right now. You can also wind the animation backwards in time to watch its launch and journey to Mars.

ExoMars Trace Gas Orbiter and Schiaperelli Lander

ExoMars 2016 - ESA Image

ExoMars 2016 Mission

This is the first of 2 ExoMars missions, the second of which will occur in 2020.

It consists of an orbiter (called the "Trace Gas Orbiter") and a lander (called "Schiaparelli") which travelled together and then separate as they reach Mars. The main objectives of this mission are to search for evidence of methane and other trace atmospheric gases that could be signatures of active biological or geological processes and to test key technologies in preparation for ESA's contribution to subsequent missions to Mars.

The mission was launched on 14 March 2016 on a Proton rocket which, due to advantageous Earth Mars positioning, flew direct to Mars in 7 months. It arrived at Mars 19th of October.

Three days before reaching the atmosphere of Mars, Schiaparelli was ejected from the Orbiter towards the Red Planet. Schiaparelli then coasted towards its destination, entered the Martian atmosphere at 21,000 km/h, decelerated using aero-braking and a parachute. It was then meant to brake with the aid of a thruster system before landing on the surface of the planet. Unfortunately something went wrong in the final stages and the thruster system switched off far to early. The lander then fell from somewhere between 2 and 4 km to strike the surface at a very high speed and possibly exploded (due to still being full of fuel) on the surface. Although this is a setback to the overall ExoMars mission, the lander was meant as a test of ESA's landing technology so as long as lessons can be learnt, it is not a complete failure. Update: To read more about the landing failure jump to here.

Schiaparelli landing site
Click for full story
.

The ExoMars Orbiter was successfully inserted into an elliptical orbit around Mars and will be manoeuvred into a circular, approximately 400km altitude orbit ready to conduct its scientific mission.

Trace Gas Orbiter

The Orbiter will perform detailed, remote observations of the Martian atmosphere, searching for evidence of gases of possible biological importance, such as methane and its degradation products. The instruments on the Orbiter will carry out a variety of measurements to investigate the location and nature of sources that produce these gases. The scientific mission is expected to begin in December 2017 and will run for five years. The Trace Gas Orbiter will also be used to relay data for the 2020 rover mission of the ExoMars programme until the end of 2022.

Schiaparelli Lander

Schiaparelli - an entry, descent and landing demonstrator module - was designed to prove ESA's technology for landing on the surface of Mars with a controlled landing orientation and touchdown velocity. The design of Schiaparelli maximises the use of technologies already in development within the ExoMars programme. These technologies include: special material for thermal protection, a parachute system, a radar Doppler altimeter system, and a final braking system controlled by liquid propulsion.

Schiaparelli was expected to survive on the surface of Mars for a short time by using the excess energy capacity of its batteries. The science possibilities of Schiaparelli were limited by the absence of long term power and the fixed amount of space and resources that can be accommodated within the module; however, a set of scientific sensors were included to perform limited, but useful, surface science.

ExoMars 2016 Mission Phases Overview

Launch 14 March 2016
Schiaparelli - Trace Gas Orbiter separation 16 October 2016
Trace Gas Orbiter insertion into Mars orbit 19 October 2016
Schiaparelli enters Martian atmosphere and lands on the target site 19 October 2016
Schiaparelli science operations begin 19 October 2016
Trace Gas Orbiter changes inclination to science orbit (74 degrees) December 2016
Apocentre reduction manoeuvres (from the initial 4-sol orbit to a 1-sol orbit) December 2016
Aerobraking phase (Trace Gas Orbiter lowers its altitude to 400 km circular orbit) January 2017 - November 2017
Trace Gas Orbiter science operations begin. (In parallel, TGO will start data relay operations to support NASA landers on Mars.) December 2017
Superior solar conjunction (critical operations are paused while the Sun is between Earth and Mars) 11 July - 11 August 2017
Start of the Trace Gas Orbiter data relay operations to support communications for the rover mission and for the surface science platform April 2021
End of Trace Gas Orbiter mission December 2022

ExoMars News

To follow latest information on the mission, visit the ESA site which will have live updates.

ExoMars Schiaparelli Landing Failure

The failure of Schiaparelli to land is really something that shouldn't have happened, but hindsight is a wonderful thing.

Schiaparelli was functioning correctly until at around 4km above the ground, it deployed it's parachute and experienced some much larger accelerations/oscillations that expected. The IMU (Inertial Measurement Unit) which measures the acceleration and turning rate in all axis, was not designed for the large angular momentum and raised a "saturation flag" which means "Gee.. we are turning in this axis more than I can measure" and kept the flag raised for quite some time whilst the spacecraft joggled about. The GNC (Guidance Navigation and Control) unit's job is to look at data coming from all the sensors and decides where and what orientation the craft is in. The GNC knew what turning rate the IMU saturates at and so when the IMU raised it's flag, the GNC started working out how far the craft had turned. After a short while the oscillations died down and the IMU again reported low turn rates. However by this time the IMU had already estimated that the spacecraft was almost completely upside down - which is wasn't.

At this point the RDA (Radar Doppler Altimeter) switched on and started measuring how far the ground was when looking straight down out of the bottom of the craft. It then reported to the GNC that the craft was about 4km from the ground.

The problem now occurred because the GNC tried to calculate the altitude of the craft given that the ground was 4km away from the crafts underside, and that the craft was now upside down. It concluded the craft was now underground.

Because the altitude was less than a preprogrammed criteria, the GNC then started the landing procedure. It ejected the back shield and parachute and fired up the retro rockets. It then calculated how long to fire the retros and because the altitude was negative it shut them down as soon as possible after just 3 seconds. The spacecraft then fell to the surface some 3.7 km below it, impacting at around 150 m/s after 34 seconds.

So in summary, the crash was caused by unexpected forces when the parachute deployed, but was due to the failure of the software to cope with simple and flagged errors in data. Having said that, this was a lander demonstrator and it certainly did it's job well. If the parachute had performed within it's expected limits then Schiaparelli would have successfully landed on Mars and the engineers would be congratulating themselves. However, a successful landing would have never shown the problem lurking in the software which might have destroyed the next real, and many times more expensive, Exomars 2020 lander.

Link : The Technical Report on the Schiaparelli Crash.

More Information:

ExoMars ESA Site
ExoMars Wikipedia