For instance, the usage of the satellite’s limited onboard resources, especially the SSR (Solid State Recorder) and the power status, needs to be fully cross-checked before a command load generation for either mission objective of payload. To meet both mission objectives and to accomplish conflict-free planning and scheduling, the mission operations have been more complicated than traditional dedicated Earth remote sensing satellites. The RSI instrument is operated in the daytime (sunlit period), while the ISUAL is active during the nighttime (eclipse period) of the orbit. Fall 2013: The FormoSat-2 satellite has been operated on orbit for more than 9 years (design life of 5 years).The spacecraft experienced malfunctions of one gyro and one reaction wheel. FormoSat-2 is currently in a good state of health, as investigations of the trending data of each subsystem verified (including RSI, C&DH, TT&C, Power, Thermal, Propulsion, and AOCS).
The remaining on-board propellant is 27 kg, which is sufficient for orbit maintenance of another 10 years. On May 21, 2014, FormoSat-2 will have been on-orbit for 10 years, with continuous monitoring for Taiwan and the world (the design life of 5 years has been doubled).
2014: The FormoSat-2 mission is operating nominally.
2) 3) 4) 5) 6)įigure 10: Schematic for mission operations during various orbital phases (image credit: NSPO) The spacecraft wet mass is about 760 kg including 81 kg of propellant (N 2H 4) mass. The S/C provides a body-pointing capability of ±45º in roll and pitch (45º pitch in 60 s, 10º roll in 25 s, 30º roll in 60 s, respectively). The entire S/C architecture is designed in such a way as to provide a low roll inertia, a key factor for satellite agility and instrument line-of-sight stability. The fixed solar array uses GaAs cells and consists of two deployable flaps. The pointing accuracy is < 0.7 km (0.12º) the position knowledge is < 70 m (0.02º). The lower deck carries the four reaction wheels and the autonomous propulsion module. The upper deck of the platform carries the payload (RSI and ISUAL) and also part of AOCS (Attitude and Orbit Control Subsystem), namely the star sensors, gyroscopes and an IRU (Inertial Reference Unit). The S/C structure consists basically of a hexagonal body of 1.6 m side length (diameter), 2.4 m in height. There were also contributions from Taiwanese industry (including satellite computers, S-band antennas, and sun sensors). The spacecraft bus has been built by EADS Astrium SAS (prime contractor) of Vélizy, France, based on the Leostar 500 XO family. Note 2: In 2005, the National Space Program Office was renamed to “National Space Organization”, keeping the same acronym, NSPO.įigure 1: Artist's view of the FormoSat-2 spacecraft in orbit (image credit: NSPO) 1) At the end of this contest, the ROCSat program was given the new name of FormoSat in December 2004. Note1: A public naming competition took place in Taiwan in 2004 with regard to the ROCSat satellite program. The ROCSat program is part of a long-term effort in Taiwan to develop an autonomous space capability. Quick approval of the export of ROCSat-2 was provided by the French government. 1999 when NSPO signed a new contract with MMS (now Astrium SAS of France). However, the German government refused to give DASA/DSS an export licence for the S/C (the People's Republic of China was protesting the deal). Daily image coverage of Taiwan and the surrounding region is required.īackground: A contract was signed in May 1999 between NSPO and DASA/DSS (Dornier Satelliten Systeme GmbH) of Germany to build a high-resolution optical imaging satellite. ROCSat-2 is an NSPO (National Space Program Office) of Taiwan Earth imaging satellite with the objective to collect high-resolution panchromatic (2 m) and multispectral (8 m) imagery for a great variety of applications such as in land use, agriculture and forestry, environmental monitoring, natural disaster evaluation, and in support of research interests, in particular with the ISUAL instrument. FormoSat-2 / ROCSat-2 (Republic of China Satellite-2)