Genesis Mission Reference Orbit Has Been Defined

The reference orbit for the Genesis satellite mission starting on 1 January 2028 (00:00:00 UTC) has been defined, providing a detailed baseline for mission analysis and scientific activities.

The Genesis Reference Orbit files in Earth-Centered Inertial (ECI) and Earth-Centered Earth-Fixed (ECEF) frames are now available in SP3 format in the GSSC archive, under the path /pub/satellite/genesis/2028. Additionally, a supporting document is provided detailing the initial orbital elements and the dynamic modelling adopted for the Genesis orbit generation.

The orbit propagation relies on advanced dynamic models following IERS 2010 conventions, including high-precision modelling of Earth’s gravity field, ocean tides, solid Earth tides, and third-body perturbations from the Sun, Moon and planets. An important caveat is that in the absence of realistic future values, all Earth Rotation Parameters (ERP) were assumed equal to zero for the propagation.

The satellite, with a mass of 406 kg, is modelled using a cannonball radiation pressure model to account for solar radiation pressure as well as Earth albedo and infrared radiation effects.

At the reference epoch, the spacecraft is placed in a near-circular orbit with the following parameters:

• Semi-major axis: 12,378.9 km
• Eccentricity: 0.001297
• Inclination: 95.49°
• Right Ascension of Ascending Node (RAAN): 359.624°
• Argument of Perigee: 59.08°
• True Anomaly: 340.711°

This orbit configuration supports the mission’s scientific objectives by enabling precise geodetic observations and stable long-term tracking conditions. The published reference orbit provides a common baseline for simulation, analysis, and future mission planning activities related to Genesis.

Sincerely yours,

ESA PROAD Team