An insertion burn at local noon has the advantage that the spacecraft is kicked into a 1?1 resonant orbit, with an inexpensive recovery manoeuvre, if the insertion burn fails. However this was disregarded for thermal reason.

1
ADVANCED TOPICS IN ASTRODYNAMICS Barcelona, July
5-10, 2004 USE OF GRAVITATIONAL CAPTURE FOR THE
BEPICOLOMBO MISSION TO MERCURY Stefano
Campagnola, Rüdiger Jehn Mission Analysis Office
ESA/ESOC, Darmstadt, Germany Stefano.Campagnola_at_e
sa.int
THE BEPICOLOMBO MISSION TO MERCURY
(2) Earth 1 Nov 2013
f MERCURY at arrival 60ltfMElt120, 240ltfMElt300
i MMO / MPO 90
b MMO / MPO 0
h periherm MMO / MPO 400 km
h apoherm MMO 12000 km
h apoherm MPO 1500 km
w MMO 178
w MPO 196
BepiColombo is the ESA cornerstone mission to
Mercury. The launch of the spaceprobe is foreseen
for the year 2012. The two elements of
BepiColombo, a planetary orbiter (MPO) and a
magnetospheric orbiter (MMO), will reach their
final destination in late 2016. In its long
interplanetary trip, BepiColombo will exploit
low-thrust arcs provided by the Solar Electric
Propulsion Module (SEPM), as well as swingbys at
the Moon, Earth, Venus (twice), and Mercury
(twice).
(5) Mercury1 28 Jun 2016
(6) Mercury2 7 Aug 2016
Arrival 26 Nov 2016
Tab 1 Target orbits for MMO and MPO
(3) Venus1 27 Mar 2014
(4) Venus2 7 Nov 2014
(1) Moon 23 Jul 2012
At arrival to Mercury, a chemical insertion
manoeuvre will be performed to insert the two
elements into the MMO target orbit (400x12000
km), from where MPO will eventually be inserted
into its target orbit (400x1500 km)
Fig 2 Definition of the b angle
Fig 1 BepiColombo Interplanetary trajectory
with the swingby dates
HYPERBOLIC APPROACH
Launch Date 3 May 2012
Lunar Flyby Date 23 Jul 2012
Arrival Date 26 Nov 2016
SEP consumption 6.46 (7.65) km/s
CH consumption 0.355 (0.398) km/s
Maximum Thrust (SEPM) 400 mN
Cruise Time 4.35 years (1589 d)
Initially the optimum trajectory was determined
for a hyperbolic approach. However a failure of
the chemical insertion burn would result in a
failure of the mission, as the inadvertent flyby
would send the spacecraft away from Mercury.
Tab 2 Summary of the hyperbolic approach
including navigation, margin, corrections for
non-nominal arrival conditions
An insertion burn at local noon has the advantage
that the spacecraft is kicked into a 1?1 resonant
orbit, with an inexpensive recovery manoeuvre, if
the insertion burn fails. However this was
disregarded for thermal reason.
Fig 3 Hyperbolic approach and target orbits
GRAVITATIONAL CAPTURE
The use of the gravitational capture is now
considered. Performing extended low-thrust arcs
until some 30 days before arrival, the spacecraft
will attain very low relative velocity with
respect to Mercury, and will orbit temporarily
around it before escaping again as a result of
the Sun perturbation. Two interesting cases are
presented here. More results and further analysis
will soon be published.
CASE A (left) Nominal Arrival Date 5 Jan
2017 MJD2000 6214.4 Arrival osculating
orbit 400x200000 km
CASE B (right) Nominal Arrival Date 5 Jan
2017 MJD2000 6214.9 Arrival osculating
orbit 400x180000 km
Fig 4 Incoming and recovery trajectories for
case A in a Mercury equatorial reference frame
(upper left and lower right) and in a rotating
reference frame (lower left)
Fig 5 Incoming and recovery trajectories for
case B in a Mercury equatorial reference frame
(upper right and lower left) and in a rotating
reference frame (lower right)