Investigation of long-term orbital behaviour in the high-order lunar gravity field
- Paper number
IAC-24,C1,8,1,x87080
- Author
Dr. Alessandro Masat, IMS Space Consultancy, Germany
- Coauthor
Dr. Lorenzo Bucci, Deimos Space SLU, Germany
- Year
2024
- Abstract
The strongly irregular lunar gravity field poses several challenges to the design of Low Lunar Orbit (LLO) missions. Several studies, supported by the experimental evidence provided during the Apollo program, have investigated the dynamical features of such environment, with particular focus on the stability of LLOs. A well-know result is the existence of some inclination bands, which provide a “frozen” configuration, where the orbit remains stable in the long term. Most studies are based on numerical evidence, as semi-analytical approaches exist, but cannot be used for very low orbits where even the high-order zonal and tesseral harmonics play a relevant role. The study provides a comprehensive numerical investigation of LLO stability, using both a spherical-harmonics-based dynamics, and another based on mascon models. The aim is to investigate the stability regions of the LLO environment (50-1000 km altitude), searching for stable conditions both for circular and elliptical orbits, and identifying the threshold where the different perturbations (solar gravity, Earth gravity, high-order harmonics) are dominant. The first objective may help the mission designer to identify mission options, where long-term stability is sought or needs to be avoided; the second objective, complementarily, aids in saving calculation time, using only the necessary models in the appropriate application. The results are first validated with existing literature, confirm the four “frozen” inclination values for circular LLOs; then, besides the identification of stable orbits, the unstable solution are explored, characterizing the impacts on the lunar surface. Preliminary results suggest evidence of areas where the impacts are clustered, together with portions of the surface where impacts are very unlikely, irrespective of the initial orbital conditions. These areas, if properly identified and characterised, can provide novel solutions and applications to both surface missions and debris analyses, e.g. supporting on-orbit fragmentation studies. Additionally, the works compares the different models and software available, exploring both CPU- and GPU-based propagation, highlighting the benefits of both approaches and their applicability to the different research fields.
- Abstract document
- Manuscript document
IAC-24,C1,8,1,x87080.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.