Mars Express: Toward a 20-year scientific and technical success story

<p>Mars Express, ESA's first flagship for Mars exploration, will reach the momentous milestones of 20 years in space and at Mars on 2 June and 25 December this year, respectively. Its scientific record is unprecedented for a mission which was initially planned for one Martian year. Since end 2003 Mars Express has gathered a wealth of data from the subsurface, surface, atmosphere, plasma environment and moons of the red planet in a quasi-uninterrupted and routine way. Furthermore, Mars Express is currently as scientifically active and productive as at any time through its lifetime in space, thanks to several additions and improvements recently made to its spacecraft and payload capabilities (e.g., MARSIS radar new subsurface and Phobos operative modes, radio frequency occultation measurements between Mars Express and ESA&#8217;s Trace Gas Orbiter using an upgraded MELACOM communications system, plasma sounding by ASPERA during MARSIS measurements, occultation observations during egress). Mars Express is expected to maintain and even enhance its scientific return over the next few years, should the mission be extended. Technical feasibility of further mission extensions has been reviewed and confirmed. The mission is constrained by 3 lifetime-limiting elements which are the remaining gyro lifetime, remaining fuel and the battery lifetime. However, it has been demonstrated that none of those 3 constraints is likely to prevent Mars Express from continuing its routine operations until beyond 2030. Whether Mars Express is extended or not, nominal archiving is proceeding at pace and higher-level data sets being produced in collaboration with the PI teams to optimise the Mars Express archive legacy.</p> <p>The mission and science operations teams, together with the mission scientists, are looking forward to several additional years of scientific productivity and discoveries. Successful joint science campaigns with the CNSA Tianwen/Zhurong orbiter and rover missions, UAE&#8217;s Hope orbiter mission, and especially the upcoming MMX mission to Phobos by JAXA should contribute to further augment Mars Express&#8217; 20-year success story.</p>