SumbandilaSat

SumbandilaSat (sometimes just Sumbandila, formerly ZASAT-002, AMSAT designation SO-67ANS-294 AMSAT News Service Special Bulletin SumbandilaSat Designated as SO-67, AMSAT News Service, bulletin ANS-294 of 2009-10-21 (naming as OSCAR), accessed 2009-10-25), was a South African micro Earth observation satellite, launched on 17 September 2009 on a Soyuz-2 launch vehicle from the Baikonur Cosmodrome. The first part of the name, Sumbandila, is from the Venda language and means "lead the way".

The University of Stellenbosch, SunSpace and the CSIR (Council for Scientific and Industrial Research) were key players in constructing SumbandilaSat. The CSIR's Satellite Application Centre (CSIR-SAC) was responsible for operations, telemetry, tracking, control as well as data capturing.

SumbandilaSat was part of a closely integrated South African space programme and served as a research tool to investigate the viability of affordable space technology. Furthermore, the data was used to, amongst others, monitor and manage disasters such as flooding, oil spills and fires within Southern Africa.

In June 2011 the satellite was damaged during a solar storm. The damage caused the on-board computer and the camera to stop functioning. This has caused it to stop fulfilling its primary objective and it has been written off as a loss by SunSpace, its builder. The final data packet from the satellite was received on 14 September 2011.

Launch site The launch site was the Baikonur Cosmodrome LC-31/6, which is located at the following coordinates:

Satellite specifications + General satellite specificationsItemSpecification ImagerNER < 0.6% with a forward motion compensation (FMC) factor of 4:1Operational MTF: >= 5% over the full field (excluding orbit motion effects)GSD = 6.25m @ an orbit altitude of 500 km6 spectral band (visible range) line scannerMatrix sensor included for "snapshot" picturesImage quantisation: 12-bit (data for each pixel stored as 2 bytes) Image modesDefault scan mode with FMC = 4:1 but system could operate with FMC = 1:1 with consequent degradation in NERIn FMC = 4:1 mode, non-contiguous scenes of 45 km x 45 km could be imaged (max 10 scenes in 6 spectral bands before data downloading was required)In FMC = 1:1 mode, a contiguous strip with 45 km swath could be imaged (max track length of 450 km could be imaged in 6 spectral bands before data downloading was required)Imager data store24 Gbyte Image data downlinkExpected frequency implemented on satellite exploration S-bandLink margin: 3 dB @ 10° (calculated with 0dBi satellite antenna; 5W Tx power and SAC GS parameters)Data rate sufficient to download full image data store during two night passesNo real-time downloading of images (all images stored on board the satellite) ViewfinderLive downlinking of PAL video images during TT&C ground station passesPAL images selectable between B&W (narrow FOV) and two wider FOV colour PAL camerasSatellite bore-sight steerable with "joystick" interfaceViewfinder mode could be interrupted with either image snapshot or image linescan modes upon ground commandThe bore-sight direction of the viewfinder was the same as the main imager ADCS systemThe satellite was 3-axis stabilisedSystem performance was sufficient to maintain pointing accuracy for image downloadingADCS performance did not degrade image qualityThe satellite bore-sight could be controlled to within 3 km on the groundThe intended system implementation used a combination of the following actuators and sensors: Horizon, fine-Sun, coarse-Sun sensors; star camera; magnetometer(s); fibre-optic gyros; reaction wheels and magneto torquersA satellite slew manoeuvre from one stabilised position to another stabilised position, through an angle of 30°, could be completed in less than 1 minute Propulsion SystemSufficient propellant included to maintain a satisfactory orbit for 3–4 yearsSystem was to demonstrate orbit constellation deployment as well as orbit maintenance TT&C Communication LinkExpected frequencies implemented on commercial VHF uplink and UHF downlinkLink margin: 6 dB @ 5° (calculated with -12dBi satellite antenna null; 5W Tx power and 12dBi GS antenna gain)Satellite HousekeepingOne TT&C GS pass per 24h was sufficient for the purpose of monitoring telemetry and uploading of new command sets and SW PowerEnergy source: solar panel with 65W (EOL) capacityMission planning dictated energy requirements per orbit ExperimentsProvision was made for two 1-kg experimentsSU certified the space environmental readiness of the experiments at MC level prior to integrationAverage power available per experiment: 1.2W (TBC)Peak power available per experiment: 10W (TBC) Orbit lifetimeDesign lifetime of 3 years at an orbit altitude of 500 km (subject to average Sun activity)Given the ultimate unpredictability of the space environment, the operational life varied from the design lifetime

* Courtesy of SunSpace

On-board experiments It had a number of secondary experimental payloads on board:

Stellenbosch University — Architectural radiation experiment for commercial off the shelf devices and a software defined radio project. Nelson Mandela Metropolitan University — A forced vibrating string experiment. University of KwaZulu-Natal — Very low frequency (VLF) radio experiment. SA AMSAT — 2m/70 cm amateur radio transponder, parrot repeater and a voice beacon. The AMSAT designation of this payload is SO-67.

SumbandilaSat

Bron en licentie