Speaker
Description
Orbital decay in low Earth orbit (LEO) is strongly influenced by solar activity, which modulates atomic and molecular density at high altitudes and thus increase the drag force. It is a significant concern for satellite operators at LEO in terms of constellation management and satellite operational lifetime perspective. This poster explores how variations across the solar cycle affect satellite lifetimes and reentry predictions using AGI STK’s high-fidelity drag propagation models up to 3-sigma solar flux data. Four main scenarios are investigated by their correspondance with solar flux affecting the atmospheric drag calculations: 2022 - rising, 2025 - peak, 2027 - declining and 2030 - minimal solar flux (F10.7) cases. A representive 3U and 6U LEO cubesat satellites is simulated at 500 km altitude at circular Sun-synchronous orbit (SSO) and 45 degree of inclined orbit with corresponding multiple decay models studied together with overall ensemble predictions as well.
Results show that the cubesats deployed to orbit at declining phase of the solar cycle has the least effect on the lifetime (> 5 years for 3U cubesat at 500 km altitude) and the maximum of the solar cycle (considering that the mission started at 1 Jan 2025), has the highest effect on the lifetime (<< 2 years for 3U cubesat). This poster summarizes the ensemble lifetimes analyzed with different algorithms for 3U and 6U cubesat decay - reentry predictions.
As several cubesats on the CELESTRAK orbital decay database dedicated FLOCK constellation (3U form factor) satellites, which approximately had 510+ km apogee altitude at beginning of life, are in line with the 2022 scenario for the increasing solar activity case with average lifetime of 2.65 years (most of them had entered the atmosphere in 2024) which is closer to the ensemlbe lifetime values of 1-sigma for this satellite deployment case. These insights support accurate mission planning and responsible end-of-life management in the context of increasing LEO congestion.
