Engineers and researchers at the French South African Institute of Technology at the Cape Peninsula University of Technology (CPUT) are in an advanced stage of developing the institution’s second nanosatellite, designated ZACube-2. “CPUT has used CubeSat programmes to encourage students to train as engineers and even to remain at the institution after graduating,” explains CPUT Electrical Engineering Department senior engineer Nyameko Royi. “And we undertake outreach programmes to schools, at which CubeSats are featured.”
“The CPUT model of having postgraduate students build nanosatellites is a good one,” affirms South African National Space Agency (Sansa) CEO Dr Val Munsami. “When SunSpace and the University of Stellenbosch developed the Sumbandila small satellite, they had students working alongside the engineers. One of the students was responsible for mission control. Another was involved in integrating the satellite onto the [Russian] Soyuz launch vehicle. All have gone on to successful careers.” (SunSpace subsequently went insolvent and was taken over by the Denel group, becoming Denel Dynamics Spaceteq.)
“We’ve almost finished ZACube-2,” reports Royi. It is a 3U Cubesat, its dimensions being 10 cm × 10 cm × 30 cm. “It is undergoing environmental testing and should be launched during the second half of this year.”
The main payload for the new nanosatellite is an automatic identification system (AIS) tracker for shipping. This takes the form of a very high frequency software-defined radio (SDR), which was developed in conjunction with a partner institution. It will track AIS transponders on ships sailing in or through South African waters. Ships with a gross tonnage of 300 t or more, sailing on international voyages, or ships of 500 gross tons or more not engaged in international voyages, and passenger vessels of all sizes, are required by the International Maritime Organisation to be fitted with an AIS. This requirement came into effect on December 31, 2004.
ZACube-2’s primary mission is linked to the government’s Operation Phakisa initiative to develop the country’s maritime economy. It is intended to act as a precursor mission to test the SDR and its applicability to AIS tracking. If all goes well, it will be followed by a constellation of nanosatellites which will be used to track shipping in South African waters. It is possible that, if successful, the mission might be offered for use by other countries. (Such a constellation would complement, not replace, patrol aircraft or patrol vessels, allowing these other assets to be used more efficiently.)
“The secondary payload is a near-infrared camera with a 60 m resolution that will mainly be used for veld fire detection. This resolution is adequate to detect veld fires,” says Royi. “This camera has been developed in cooperation with the Council for Scientific and Industrial Research. We did the electronics – they did the optics.”
CPUT’s first nanosatellite, ZACube-1, also known as TshepisoSat, is a 1U CubeSat – that is, it is in the original CubeSat format, having dimensions of 10 cm × 10 cm × 10 cm. It was launched in November 2013 on board a Russian Dnepr rocket from the Yasny launch base, in the Orenburg region of Russia.
“It is still operating, although not fully, after more than four years in space,” highlights Royi. Its main payload was a high-frequency radio, which is no longer working. Associated with this radio was a 10-m-long antenna, which was deployed in orbit; the purpose, and the primary mission of the nanosatellite, was to characterise the SuperDARN antennas then being set up in Antarctica by Sansa. (SuperDARN stands for Super Dual Auroral Radar Network: these radars provide data on space plasma in near-earth space, its interactions with the earth’s atmosphere, and the effects of these on human infrastructure, especially communications and energy. The Sansa SuperDARN is part of an international network of such radars, located in the Arctic and Antarctic regions.)