SumbandilaSat

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SumbandilaSat
Mission type Technology
Operator University of Stellenbosch
COSPAR ID 2009-049F
SATCAT № 35870
Spacecraft properties
Manufacturer SunSpace
Launch mass 81 kilograms (179 lb)
Start of mission
Launch date September 17, 2009, 15:55:07 (2009-09-17UTC15:55:07Z) UTC
Rocket Soyuz-2-1b/Fregat
Launch site Baikonur 31/6
End of mission
Deactivated June 2011 (2011-07)
Orbital parameters
Reference system Geocentric
Regime Low Earth
Perigee 467 kilometres (290 mi)[1]
Apogee 472 kilometres (293 mi)[1]
Inclination 97.16 degrees[1]
Period 93.85 minutes[1]
Epoch 21 September 2014, 02:35:28 UTC[1]

SumbandilaSat (formerly ZASAT-002, AMSAT designation SO-67[2]), is a South African micro earth observation satellite, launched 2009-09-17 on a Soyuz-2 launch vehicle from the Baikonur Cosmodrome.[3] 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) will be responsible for operations, telemetry, tracking, control as well as data capturing.

SumbandilaSat is part of a closely integrated South African space programme and will serve as a research tool to investigate the viability of affordable space technology. Furthermore, the data will be 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 has been written off as a loss by SunSpace, its builder.[4]

Launch site[edit]

The launch site at the Baikonur Cosmodrome is known as LC-31/6, and can be found in at the following coordinates:

Satellite specifications[edit]

General satellite specifications
Item Specification
Imager NER < 0.6% with a forward motion compensation (FMC) factor of 4:1
Operational MTF: >= 5% over the full field (excluding orbit motion effects)
GSD = 6.25m @ an orbit altitude of 500 km
6 spectral band (visible range) line scanner
Matrix sensor included for "snapshot" pictures
Image quantisation: 12-bit (data for each pixel stored as 2 bytes)
Image modes Default scan mode with FMC = 4:1 but system can operate with FMC = 1:1 with consequent degradation in NER
In FMC = 4:1 mode, non-contiguous scenes of 45 km x 45 km can be imaged (max 10 scenes in 6 spectral bands before data downloading is required)
In FMC = 1:1 mode, a contiguous strip with 45 km swath can be imaged (max track length of 450 km can be imaged in 6 spectral bands before data downloading is required)
Imager data store 24 Gbyte
Image data downlink Expected frequency to be implemented on satellite exploration S-band
Link margin: 3dB @ 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 passes
No real-time downloading of images (all images stored on board the satellite)
Viewfinder Live downlinking of PAL video images during TT&C ground station passes
PAL images selectable between B&W (narrow FOV) and two wider FOV colour PAL cameras
Satellite bore-sight steerable with "joystick" interface
Viewfinder mode can be interrupted with either image snapshot or image linescan modes upon ground command
The bore-sight direction of the viewfinder is the same as the main imager
ADCS system The satellite is 3-axis stabilised
System performance is sufficient to maintain pointing accuracy for image downloading
ADCS performance shall not degrade image quality
The satellite bore-sight can be controlled to within 3 km on the ground
The intended system implementation will use 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 torquers
A satellite slew manoeuvre from one stabilised position to another stabilised position, through an angle of 30°, can be completed in less than 1 minute
Propulsion System Sufficient propellant included to maintain a satisfactory orbit for 3–4 years
System will demonstrate orbit constellation deployment as well as orbit maintenance
TT&C Communication Link Expected frequencies to be implemented on commercial VHF uplink and UHF downlink
Link margin: 6dB @ 5° (calculated with -12dBi satellite antenna null; 5W Tx power and 12dBi GS antenna gain)
Satellite Housekeeping One TT&C GS pass per 24h will be sufficient for the purpose of monitoring telemetry and uploading of new command sets and SW
Power Energy source: solar panel with 65W (EOL) capacity
Mission planning will dictate energy requirements per orbit
Experiments Provision is made for two 1-kg experiments
SU will certify the space environmental readiness of the experiments at MC level prior to integration
Average power available per experiment: 1.2W (TBC)
Peak power available per experiment: 10W (TBC)
Orbit lifetime Design 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 can vary from the design lifetime

* Courtesy of SunSpace

On-board experiments[edit]

It has a number of secondary experimental payloads on board:[5]

See also[edit]

  • SUNSAT, first South African satellite

References[edit]

External links[edit]