TWSAT - Mission Operations Plan
- Paper number
IAC-08.B4.3.9
- Author
Mr. T. Parimalarangan, Indian Space Research Organisation (ISRO), India
- Year
2008
- Abstract
India is playing a lead role in remote sensing technology and would like to extend this role by providing access to the remote sensing data from an Indian satellite to students/scientists in third world countries. Keeping this in view ISRO has developed a micro satellite called TWSAT carrying an optical camera to provide multi-spectral data (4 bands) to third world having a resolution of 37 ms with a swath of 151 Kms. It is also planned to have a Hyper spectral imager as an additional payload in TWSAT which will enhance the mission capability by providing data for ocean and atmospheric studies. This payload has a resolution of 500m with a swath of 130 Km. The spacecraft is a low earth orbit of 636 Km altitude with a mission life of two years. The mass of the satellite realized is around 75 Kg in the micro satellite category. ISTRAC is going to play a major role in TWSAT mission operations by tracking and controlling it through out mission life since launch using the network of ground stations optimally, in addition to the day-to day payload programming. As TWSAT uses S-band frequency for both TTC operations and payload downlink with a single transmitter in low/high power mode normal telemetry data will not be available during payload operations imposing a constraint in carrying out mission operations. Hence it is planned to strip the telemetry data embedded in payload data using stripper software developed in ISTRAC. This stripped telemetry data can be used to carry out mission operations at SCC during Real time. TWSAT is nominally a Sun pointing mission a continuous roll bias profile is provided to satisfy star sensor mounting requirement. Also a fixed latitude dependent yaw bias for one imaging session is planned for every HySI payload operation to minimize the swath reduction and to meet band-to-band registration. Nominally it is planned to operate HySI payload over Indian region and Multi spectral camera (Mx-T) over other regions. It is anticipated that around thirty user terminals from the third world developing countries will receive Mx-T data during its operational phase. During imaging satellite will be earth pointing realized through attitude maneuver by control system prior to image start. The intricacies involved in handling the TWSAT mission to reap the maximum benefit of the payloads are discussed in this paper.
- Abstract document
- Manuscript document
IAC-08.B4.3.9.pdf (🔒 authorized access only).
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