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| Titel |
The BepiColombo mission to Mercury: ISA accelerometer on-ground and in-flight calibration procedures |
| VerfasserIn |
V. Iafolla, D. Lucchesi, E. Fiorenza, M. Lucente, C. Lefevre, C. Magnafico, R. Peron, F. Santoli, S. Nozzoli, A. Argada |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250063902
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| Zusammenfassung |
| The key role of the Italian Spring Accelerometer (ISA) in the radio science measurements of
the ESA BepiColombo mission to Mercury is to remove, aposteriori, the non-gravitational
accelerations acting on the Mercury Planetary Orbiter (MPO) due to the very strong radiation
environment around Mercury. This presentation is devoted to describe the main on-ground
and in-flight calibration procedures that are necessary to guarantee the accelerometer
performance in order to reach the very ambitious objectives of the Radio Science
Experiments (RSE) of the ESA mission: the accelerometer sensitivity has to be 10-8
m/s2/-Hz in the frequency band 3-
10-5
-10-1 Hz.
ISA is a three axes torsional accelerometer and the calibration procedures are necessary in
order to estimate scale factors and axes misalignments and couplings.
The on-ground calibration procedures are primarily finalized to the determination of the
actuator transducer factor of the proof-masses capacitor plates and to the determination of the
proof-masses axes orthogonality and orientation with respect to a reference optical
cube.
The in-flight calibration procedures are devoted to the determination of the accelerometer
pick-up transducer factors, which are different from those determined on-ground during the
calibration of ISA’s actuators, and to the determination of the axes alignment in order
to check if launch shocks have produced possible variations with respect to their
nominal orientation in the MPO body-fixed frame as determined during the pre-launch
characterization and calibration. A by-product of the in-flight calibration procedures is the
determination of ISA proof-masses position with respect to spacecraft effective
center-of-mass. This allows to check if the MPO center-of-mass variations are in line with
on-ground estimates based on fuel consumption computations and the mass distribution of
the spacecraft appendices and movable parts, as in the case of the orientation of the solar
array panels and of the High Gain Antenna (HGA). The presentation will focus in the
description of the above calibration procedures and their corresponding error budget estimate. |
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