A Study on the Analysis of Visibility between a Lunar Orbiter and Ground Stations for Trans-Lunar Trajectory and Mission Orbit

Abstract

Korean government plans to launch a lunar orbiter and a lander to the Moon by 2020. Before launch these two proves, an experimental lunar orbiter will be launched by 2018 to obtain key space technologies for the lunar exploration. Several payloads equipped in experimental lunar orbiter will monitor the surface of the Moon and will gather science data. Lunar orbiter sends telemetry and receives tele-command from ground using S-band while science data is sent to ground stations using X-band when the visibility is available. Korean deep space network will be mainly used for S and X-band communication with lunar orbiter. Deep Space Network or Universal Space Network can also be used for the S-band during trans-lunar phase when korean deep space network is not available and will be used for the S-band in normal mission orbit as a backup. This paper analyzes a visibility condition based on the combination of various ground antennas and its mask angles according to mission scenario to predict the number of contacts per day and to build an operational scenario for the lunar orbiter.

Flight Dynamics and Navigation for Planetary Missions in Korea: Past Efforts, Recent Status, and Future Preparations

“…In addition, the 3.5 phasing loop can guarantee similar lunar arrival times and geometries by adjusting the final phasing loops, and additional time slots for system and operation checkouts can also be secured. As the reference trajectory of KPLO was selected as a 3.5 phasing transfer, Choi et al (2016) analyzed a visibility condition of KPLO based on the combination of various candidate ground stations and the masking angles by utilizing 3.5 phasing options. In addition, the optimum satellite-Earth-Moon (SEM) angle is suggested in Choi et al (2018a) from a number of viewpoints including launch epoch, coast duration, perigee altitude, and delta-Vs, regarding not only the transfer but also LOA phases as the SEM angle defined in the Earth-Moon rotating frame is a critical constraint in evaluating the 3.5 phasing loop transfer trajectory.…”

Analysis on Delta-Vs to Maintain Extremely Low Altitude on the Moon and Its Application to CubeSat Mission

“…After completing the KPLO mission, future missions will focus on lunar surface investigations using landers and rovers (Song et al 2018). For the successful flight operation of the KPLO, considerable relevant works have been performed focused on: trajectory design (Choi et al 2016(Choi et al , 2018, error and contingency analysis (Bae et al 2016a, b;Bae et al 2017a, b, c;, flight dynamics subsystem development (Lee et al 2017;Kim et al 2017a;Song et al 2016;, and navigation analysis (Kim et al 2016a, b;Kim et al 2017b, c, d, e;Kim et al 2018a, b, c;Kim et al 2019), among others.…”