PROMPT: Responsive observation methodology from call-up and launch

摘要

PROMPT (PRompt Observation Methodology with intelligent Pointing and Testing) is a project to realize a responsive satellite to observe a target data and downlink the obtained data in less than half a day after call-up and launch of the satellite. This project is funded by ImPACT (Impulsing Paradigm Change through disruptive Technologies) programs. To accomplish this goal of responsive observation, the observation of the target area is planned to be done in the first orbit pass after separation from the launcher, and the transmission of the observed data to a ground station in the second orbit pass. So, there is no opportunity for ground staffs to check telemetries of the satellite and uplink commands from the ground station. It is impossible to change a configuration of the satellite and a sequence of operations from ground even in case that malfunctions or any deviations from planned scenario are happened, and so highly onboard autonomous functions are required. This paper proposes and discusses this concept and autonomous functions being developed in PROMPT. First of all, background and a concept of PROMPT is described. Then, a list of risks to be considered in achieving the target observation and data transmission to the ground are described. Malfunctions of satellite components, orbit deviations caused by the launcher should be dealt with by onboard autonomous functions. Next a timeline and sequence for recovery against the predicted listed risks will be proposed. Then the autonomous function will be described to achieve this timeline and sequence. This function has a behavior model of the satellite to recognize its current status and to generate necessary commands to achieve the goal. The proposed function enables more robust operations against anomalies or deviations from the original operation plan than ever without a ground support, which is necessary feature of PROMPT.