Orbit monitoring and space environment simulations of the satellite M26 of BDS

No. 3 BeiDou navigation satellite system (No. 3 BDS) has been open to worldwide users since 2020. Its navigation service benefits more and more people from different countries. The satellite M26 is one of the standby satellites of BDS, which was sent into its operation orbit by the end of the year 2023. Its functions include stabilizing BDS, replacing the nearly retired satellite, and carrying out assessments of the new concept of GNSS. Due to the importance of satellite M26, authors have gathered the key orbit elements information; the orbit altitude, eccentricity and orbit inclination have been completely monitored and analyzed since its launch into working orbit. Based on the orbit elements, space environment effects for the first 271-day stay in orbit of M26 are simulated and space collision probability between M26 and other objects is studied. This work will partially support M26 to quickly join in the routine operation of BDS.