RocketSTEM Issue #14 - March 2017 | Page 6

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 .