HAMSAT - SMALL SATELLITE OPERATIONS, A CASE STUDY

摘要

HAMSAT is a micro-satellite, launched as an auxiliary payload onboard the Indian Launcher, PSLV-C6, on 5 May 2005. The mission was driven by an objective of developing and operating a micro-satellite, flying a payload for the benefit of the radio amateur community and testing of various new elements / technologies, such as onboard autonomy for attitude and spin control through a miniature Bus Management Unit, high efficiency GaAs solar cells, Li-Ion battery, miniature magnetometers, indigenous RF components etc. Thus, all the new elements / technologies have provided the much-required input from the space environment and endowed with confidence for the high-tech, future operational micro satellites of ISRO. The satellite was designed to be a passive spinner, with no redundancy onboard, but for the payload transponder. The TTC operation is in VHF, while the payload is operating in UHF&VHF for uplink and downlink, respectively. Thus, the mission needs to be supported in VHF-TTC, for the purpose of telemetry, telecommand and tracking. To match the onboard autonomy, ISTRAC has installed an automated, low-cost and state-of-the-art VHF TTC ground system. The major challenge was to integrate various modules that will serve the mission specifications and the mission itself. This design has set the tone for low-cost ground systems for micro satellites of ISRO. Thus a new era has dawned in TTC operations of ISTRAC/ISRO, wherein, the tracking is carried out and TM downlinked in autonomous mode, liberating the valuable technical manpower. The normal phase operations continued to be carried out through this automated ground system, with uninterrupted services to the user community. This paper brings out the HAMSAT mission operations, design and establishment of a low cost ground system and facilitating automated operations of the tracking hardware.