Trajectory design for the Bepi-Colombo mission to Mercury

Paper number

IAC-06-C1.8.07

Author

Mr. Daniel Garcia Yarnoz, GMV S.A. at ESA/ESOC, Germany

Coauthor

Mr. Rudiger Jehn, European Space Agency/ESOC, Germany

Coauthor

Mr. Paolo de Pascale, European Space Agency/ESOC, Germany

Year

2006

Abstract

BepiColombo will be the first European mission to Mercury and the first mission ever to use solar electric propulsion to reach an inner planet. The trajectory proposed, departing from Earth on August 2013, comprises five planetary flybys (Earth, two at Venus and two at Mercury) as well as a series of low-thrust arcs that allows the delivery of two orbiters around the planet six years later. This paper presents the design of the overall trajectory, starting from a highly eccentric Earth orbit up to the polar orbits of the MMO (Mercury Magnetospheric Orbiter, JAXA) and the MPO (Mercury Planetary Orbiter, ESA). 

At departure, in order to maximize the mass delivered into an escape orbit, a strategy consisting of phasing loops and a lunar flyby was designed to leave the Earth sphere of influence. Allowing two opposite variations of the Earth to Earth arc, lunar flyby opportunities become available every 14 days. This results in the additional benefit of a more flexible launch window at low propellant costs. At arrival, a gravitational capture is employed, in which the third body perturbation of the Sun is exploited to get weakly captured around Mercury. The arrival date and apoherm height of the weakly captured orbit can be tuned to allow up to three additional recovery opportunities in case the Mercury insertion burn fails. The insertion strategy is split into several burns (three to reach MMO orbit and four more for MPO) in order to minimise the gravity losses. The design of the insertion also has to take into account constraints of visibility and orbit determination from Earth, as well as thermal constraints introduced by the design of the spacecraft. This leads to a complex multiple burn strategy that spans almost a whole Mercury year.

Results for the overall interplanetary trajectory optimization (including the lunar flyby design) as well as the approach, recovery and insertion strategies will be presented. A backup trajectory for the year 2014, which includes two additional Mercury flybys will also be briefly outlined.

Abstract document

IAC-06-C1.8.07.pdf

Manuscript document

IAC-06-C1.8.07.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.