04 www. RocketSTEM. org
By Chris Starr FRAS FBIS
So, the‘ Great Galactic Ghoul’ strikes again? This tongue-in-cheek entity is invoked by NASA scientists and engineers when missions experience difficulties, especially at Mars. After a seven month journey for ESA’ s first ExoMars mission, contact with its Schiaparelli Lander was lost just before its scheduled touch-down on 19th October last year, although its Trace Gas Orbiter( TGO) successfully entered into orbit around the Red Planet and is functioning well. However, rather than the work of a cosmic‘ gremlin’, the apparent loss of Schiaparelli appears to have been due to incorrect data triggering a premature release of the lander’ s parachute and cutting off its braking thrusters while still some 3.7km above the surface, resulting in a crash- rather than a soft-landing.
Mars has gained a bad reputation in the past, with fewer than half of the 40-plus missions sent there arriving safely and completing their mission successfully, especially in the early days of planetary exploration. Mars is not an easy target, particularly if you wish to land on its surface. Its thin atmosphere requires more than aero-braking and parachutes to slow a spacecraft down sufficiently for a soft landing. This has necessitated the use of thrusters or inflatable air-bags to ensure that landers arrive intact, making for complex automated procedures which have to function perfectly.
However, despite Schiaparelli’ s silence, ESA’ s latest orbital emissary joins a growing armada of spacecraft and landers operational at the Red Planet, more than ever before at any solar system body at any one time. These now comprise six orbiters and two rovers. ExoMars’ companions have all enjoyed spectacular success in their missions to help us understand present day conditions on Mars, as well as its past evolution.
A brief overview of these missions is given here, while ExoMars 1 is discussed in detail elsewhere in this issue of RocketSTEM.
MISSIONS CURRENTLY OPERATIONAL AT MARS AT TIME OF EXOMARS / SCHIAPARELLI ARRIVAL
Project Launch date Agency Type Remarks
Mars Odyssey |
7 Apr 2001 |
NASA / USA |
Orbiter |
Arrival at Mars on 24 October 2001. |
|
|
|
|
Expected to remain operational until 2025. |
Mars Express |
2 June 2003 |
ESA / Europe |
Orbiter |
Arrival at Mars on 25 December 2003. |
|
|
|
|
Enough fuel to remain operational until 2026. |
Opportunity |
8 July 2003 |
NASA / USA |
Rover |
Landed 24 January 2004, using a comination of parachute, |
( Mars Exploration |
|
|
|
thrusters and airbags. Still operating after over 12 years. Its |
Rover-B) |
|
|
|
twin, Spirit, also greatly exceeded expectations, but ceased operating in March 2010. |
Mars Reconnaisance |
12 Aug 2005 |
NASA / USA |
Orbiter |
Arrival in Mars orbit on 10 March 2006. |
Orbiter( MRO) |
|
|
|
|
Curiosity( Mars |
26 Nov 2011 |
NASA / USA |
Rover |
Landed on 6 August 2012, using new sky crane system |
Science Laboratory) |
|
|
|
successfully |
Mangalyaan |
5 Nov 2013 |
ISRO / India |
Orbiter |
Entered Mars orbit on 24 September 2014 |
( Mars Orbiter Mission) |
|
|
|
Primary mission completed – extension |
MAVEN( Mars Atmosphere |
18 Nov 2013 |
NASA / USA |
Orbiter |
Orbital insertion 21 September 2014. |
and Volatile EvolutioN) |
|
|
|
Mission extended until September 2018. |