BILSAT-1 communication subsystem

TUBITAK-BILTEN has initiated a project to develop and propagate small satellite technologies in Turkey. As part of this initiative, TUBITAK-BILTEN has worked with Surrey Satellite Technologies Limited (SSTL) to develop a 100 kg class enhanced microsatellite, BILSAT-1*. With the successful completion of this project, TUBITAK-BILTEN will be capable of producing its own satellites, covering all phases from design to production and in-orbit operation. The project was started in August 2001 and BILSAT-1, shown in Fig 1, was successfully launched from Plesetsk Cosmodrome, Russia in 27 September 2003. In this paper the communication subsystem of BILSAT-1 is presented. The primary uplink is the S-band receivers and the primary downlink is the S-band transmitters on-board BILSAT-1, whereas VHF and UHF systems are also present as back-up for uplink and downlink respectively, UHF/VHF system is currently being used for commissioning phase due to omni directional coverage requirements. S-band being the nominal operation system has relative directionality. The data rate of uplink is 9.6 kbps for both S-band and VHF. However, S-band is capable of 2 Mbps and UHF has 9.6 kbps, 38.4 kbps and 76.8 kbps opportunities for downlink.