Performance Enhancement of FORMOSAT-3 Follow-on Using Formation Flying

Abstract

After about 20 years of dedicated effort, the National Space Organization (NSPO) of Taiwan has successfully completed the development of Formosa satellites (FORMOSATs or FSs) 1 (FS1), 2 (FS2), and 3 (FS3). The international space community has given very positive comments on NSPO's contribution. Currently, NSPO is planning the future programs and designates FORMOSAT-7 (FS7) to be the follow-on of FS3. This paper presents the preliminary study results on the advantage of using formation flying for FS7 compared with the constellation flying of FS3. Due to the fact that the attitude control is not a major factor to affect the number of occultation data collected, it could be concluded that the formation flying is helpful but not mandatory in FS7. This conclusion is obtained by trading-off the complexity, cost, and development time of the program. We need to do is to design the orbits of the planned 12 micro-satellites to ensure the maximum number of data collection. However, during the deployment phase of FS3, it has been found that the formation flying immediately after the separation of the 6 satellites from the launch vehicle is a very important time period for instrument calibration onboard each individual satellite. Fortunately the 6 satellites of FS3 formed a formation immediately after separation from the launch vehicle without much extra effort. Therefore, no design change of the micro-satellite is required to accommodate the requirement. This experience can be duplicated in FS7 program.