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Planetary Orbit InsertionA First Success for Europe with ESA’S MarsExpress: 

Planetary Orbit Insertion A First Success for Europe with ESA’S MarsExpress Jörg Fischer, Zeina Mounzer (Vega) Michel Denis, Alan Moorhouse (European Space Agency)

The Mission : 

The Mission A new generation of science missions, known as flexi missions, built and launched in record time with a minimum cost A double mission having an orbiter and a lander, where the lander is ejected to its targeted site with high precision only a few days prior to inserting the orbiter into a Mars bound orbit. The first European attempt to send a spacecraft into orbit around another planet The first European attempt to land on another planet

Original Mission Overview : 

Original Mission Overview ~6 weeks commissioning ~5 months quiet cruise (with simulations TBD) ~1 week Mars Arrival

Complex Mission Objectives: 

Complex Mission Objectives Learn to Fly to Mars, experience building; Fly-by Orbit Land Demanding navigation & tight fuel budget Flying the mission (cruise) while simulating & training for Insertion Target & release lander 6 days before Mars arrival Mars Insertion, fixed time – one shot, contingencies Long one way light time

Unplanned Operational Challenges: 

Unplanned Operational Challenges Star tracker blinding (LEOP) Star tracker performance (scan MOI sky, sunglasses) Solar storms in late October 2003 Optimisation of orbit capture Power reduction of 28% demanding changes to the operations concept Autonomy hiccups; sophisticated FDIR, which triggered safe mode several times during cruise.

Actual Mission Overview as flown : 

Actual Mission Overview as flown 10/12/2003 2x weekly Simulations Sept. 2003 Main engine test firing ~8 weeks commissioning Cruise of -safe modes -Anomaly investigation -STR performance evaluation -Low power mission evaluation

Mars Express Mars Orbit Insertion : 

Mars Express Mars Orbit Insertion Start of Main Engine Burn Final MOI Configuration Commands Beagle 2 Ejection TCM-5 (MEX Retargeting) TCM 4 Beagle 2 Fine Targeting TCM-6 Contingency (Clean-up Manoeuvre) Navigation Recovery -10 days -5 days -4 days -2 days -1 days

Mission Critical Activities: 

Mission Critical Activities

Ejection Contingencies: 

Ejection Contingencies

Mission Timeline: SC, Stations, people: 

Team B B2 Prep MOI recovery MOI Prep Team A… …Team A Fail Ops STR slews MTL U/L Mission Timeline: SC, Stations, people

Ejection Timeline: 

Ejection Timeline

From B2 ejection to capture: 

From B2 ejection to capture Beagle 2 ejection verification involved combination of RT doppler, SC status, SC AOCS reaction to deployment, Camera images. B2 successfully verified ejected several hours after the ejection. MEX alone now on crash course – critical manoeuvre less than 5 days before arrival. After manoeuvre preliminary command stacks for SC Mars capture sequence (assuming nominal navigation) were extensively checked and uploaded to SC. Fail ops to be executed about 18 hours before arrival. safe mode still possible. Special CRPs defined even allowing recovery from safe mode 6 hours before arrival and capture around Mars

MOI Timeline: 

MOI Timeline

The Operational Achievements: 

The Operational Achievements The star tracker problems & solar storms overcome Successful lander targeting & ejection Mars insertion and operational orbit re-planned Successful Mars insertion by a series of 19 manoeuvres with high manoeuvre performance Mars Express is successfully operational in Mars orbit Mission Success achieved through Team Building

Lessons Learned: 

Lessons Learned Modifiable autonomy (software upgrades, tunable parameters) allowed to achieve more robust AOCS, is a must. MEX required safe mode to replace complete software components. Increases risk and should be avoided. Mass Memory baselined ON during capture. In actuality left OFF. Challenge the baseline. Dual simulations (phases) successful. Return worthwhile despite high workload introduced by flying and simulating. LGA during capture. Despite thorough formal processes for checks and validation the [non essential] optimal antenna selection was missed. Always question everything and extend processes to cover also non essential items Dedication led to success. Manage motivations and goals from the beginning.

Slide16: 

Science Achievements - 1st Scientific results presented 1 month after Mars arrival 3-D high resolution colour images Direct measurement of water ice at the South Pole (Jan-04) Methane detected in atmosphere (Mar-04) Observed correlation water vapour / ozone destruction Phobos high resolution observation (Aug-04) Relay of Mars images taken by NASA rover (Aug-04) Methane / water vapour correlation - possible life (Sep-04) Understanding the Martian water loss process (Sep-04) Mars Volcanoes young (Dec-04) Frozen Ice Lake at equator (Feb-05) pericentre moving Equator (Nov-04), North Pole (Apr-05) Marsis deployment pending (02-May-05) Even more exciting results anticipated in the Future …..