Orbital Lifetime Estimation of Rocket Bodies in Eccentric Low Earth, Low Inclination Orbits

Abstract

The dense population of Low Earth Orbit (LEO) due to frequent launches necessitates precise knowledge of the orbital lifetime of rocket bodies in this region. This study focuses on estimating the orbital lifetime of rocket bodies in eccentric, low-inclination LEO. Using the open-source software General Mission Analysis Tool (GMAT), the orbital lifetimes of rocket bodies with masses of 1000 kg, 1200 kg, and 1400 kg were calculated for altitudes ranging from 250 km to 500 km and inclinations of 0˚, 10˚, and 20˚. The orbital lifetimes of the defunct rocket bodies ranged from 3 to 832 days. GMAT-derived orbital lifetimes were compared with those obtained using Systems Tool Kit (STK). A subsequent 2D interpolation code was developed to interpolate the lifetime for a user-provided configuration of mass and orbital altitude. The Python code interpolated the orbital lifetimes for the given configurations with a maximum error of 5% compared to the GMAT-simulated lifetime values. This approach provides essential data for assessing post-mission disposal plans for rocket bodies and ensuring alignment with the Inter-Agency Space Debris Coordination Committee (IADC) 25-year guideline. Key findings reveal that the orbital lifetime of a rocket body increases with inclination. Additionally, it was observed that the orbital lifetime increases with mass due to slower orbital decay.