BepiColombo – Mission Analysis Challenges on the Way to Mercury
- Paper number
IAC-05-A3.P.15
- Author
Mr. Rudiger Jehn, European Space Agency/ESOC, Germany
- Year
2005
- Abstract
BepiColombo is the name of an ESA cornerstone mission to Mercury. The launch is planned for April 2012 and after a journey of 5 years two probes, the Magnetospheric Orbiter (JAXA) and the Planetary Orbiter (ESA) will reach their target orbits. The interplanetary trajectory includes flybys at the Earth, Venus (twice) and Mercury (twice), as well as several thrust arcs provided by the solar electric propulsion module. Additionally, complex strategies will precede and follow the interplanetary transfer. It starts with a lunar flyby, which is optimised to leave the Earth’s attraction with the maximum escape velocity in the required direction. At the end of the transfer a gravitational capture at the weak stability boundary is performed exploiting the Sun gravity. The small cost in interplanetary delta-V is more than compensated by the savings in the orbit insertion burn. Also in case of a failure of the orbit insertion burn, the spacecraft will stay for a few revolutions in the weakly captured orbit. The arrival conditions are chosen such that backup orbit insertion manoeuvres can be performed one, four or five orbits later with trajectory correction manoeuvres of less than 15 m/s to compensate the Sun perturbations. Only in case that no manoeuvre can be performed within 64 days (5 orbits) after the nominal orbit insertion the spacecraft will leave Mercury and the mission will be lost. Further challenges are encountered during the transfer: a) the second Venus flyby takes place just a few days after the spacecraft reappears behind the Sun b) navigation has to cope with a noisy thrust system plus limited range and Doppler availability (ground station coverage shall be minimised for cost reasons) c) the spacecraft has very stringent solar aspect angle constraints and d) recovery solutions need to be defined in case of thrust outages. A baseline trajectory taking into account all these operational constraints will be presented.
- Abstract document
- Manuscript document
IAC-05-A3.P.15.pdf (🔒 authorized access only).
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