Lesson learned from FORMOSAT-2 mission operations

Abstract

The mission operations (MO) of FORMOSAT-2 (formerly called ROCSAT-2) started from 17:47:03 UTC on 20 May 2004 after the satellite had been launch from Vandenberg, California. It took 3 days to check the performance and function of all subsystems of satellite bus, and 11 days to raise the satellite from 723 km parking orbit to 888 km mission orbit. Then the primary payload, a remote sensing instrument (RSI), was turned on and the first image was taken on 4 June 2004. In June and July of 2004, the acceptance criteria verification for bus and RSI was performed using the pre-programmed maneuver and images taken. Started from late June 2004, the secondary payload was turned on. It is an imager for sprites and upper atmospheric lightning (ISUAL). A red sprite was captured on 4 July 2004. This is the first time to observe the upward lightning phenomena between thundercloud and ionoshpere from space. The verification and validation of FORMOSAT-2 satellite including bus and payloads were completed in early August 2004. It follows the normal MO phase. During the 1 year 4 months MO from May 2004 to September 2005, a couple hundreds of anomalies (in both satellite and ground systems) and several automatic reconfiguration orders (AROs) (in satellite system) occurred. Shortly after satellite launch, the number of anomalies increases drastically. Also, the planning and scheduling system (PSS) for the RSI operation is not very efficient, and is not compatible with the very unique and advantageous capability of daily revisit of FORMOSAT-2. Some of the AROs were caused by the improper MO timeline design and results in violating satellite constraint. Almost all problems have been solved or avoided by the MO team of the National Space Organization (NSPO). In June 2005, NSPO organized a working group to review the status of health (SOH). It has been concluded that FORMOSAT-2 is in good condition except there is some shift in its orbit. We have learned many lessons from this practice. It is the purpose of this paper to share our experiences.