Mars Reconnaissance Orbiter Navigation During the Primary Science Phase

MaQuIs - Mars Quantum Gravity Mission

“…The requirement (3σ) for the MRO spacecrafts relative position to Mars is 100 m in the along track, 40 m cross track and 1.5 m in the radial direction. Results from the mission show and RMS of 3.9 m, 0.6 m and 0.9 m respectively (Highsmith et al, 2008). For MaQuIs, where unlike tracking-based gravity field solutions the position uncertainty does not translate directly into gravity field uncertainty (provided the orbit is sufficiently accurate), it is expected that a typical two-way coherent X-band Doppler link will be sufficient, and accuracy enhancements from for instance X/Ka-band tracking as is done for BepiColombo (Iess et al, 2021) will not be necessary.…”

Sequential Processing of Inter-Satellite Doppler Tracking for a Dual-Spacecraft Configuration

“…The determination of the position is more sensitive to the a priori covariance matrix RTN P 0 , especially for the transverse direction. Since deep space tracking for the MRO spacecraft enabled accuracies of ~1 m radially and ~10-20 m along-track [43], we assumed as conservative a priori uncertainty σ P = 20 m. This constraint in the position shows the good performances of the filter, leading to errors lower than 2 m. A looser a priori uncertainty leads to larger errors (>2 m) in the sequential reconstruction of the transverse position, suggesting that the combination of deep space and inter-satellite tracking is necessary to enhance the precise orbit determination.…”

Precise Orbit Determination Technique to Refine Spacecraft Mechanical Modeling

“…The solar panels are rotated independently through dedicated gimbals attached directly to the spacecraft structure to guarantee the input solar power along the MRO mid-afternoon sun-synchronous orbit. The transmission of the scientific data to the ground requires a second independent attitude of the HGA that relies on the relative direction of the Earth with respect to the orbital plane [20,21].…”