South Africa is moving quickly to put itself (and Africa) among the nations routinely using satellites to extend their reach—scientifically, technologically, economically, environmentally and for humanitarian purposes. The recent launch of the government-commissioned SumbandilaSat satellite on September 17, 2009 is in many respects a demonstration intended to show South Africa’s commitment to building capacity in small and medium satellite design and construction. But the commitment goes beyond just building systems. In addition to its capacity building role, SumbandilaSat (a Venda word chosen by school children meaning ÛÏlead the wayÛ) will provide real-time data for the benefit of the South African people to achieve many objectives, among them disaster relief, agriculture and forest sustainability, malaria prevention, elephant tracking, and urban planning.
But in order to understand the significance of SumbandilaSat, we have to begin with SunSat, South Africa’s first satellite.
In 1991 at Stellenbosch University, a first-rate research institution in South Africa’s second oldest city on the Western Cape, the faculty of the Dept. of Electrical and Electronic Engineering, ÛÏdecided to build a university satellite as a vehicle to train our graduate students in a large collaborative project as you normally find in industry,Û recalls Prof. WH (Herman) Steyn, Group Head of Computer and Control Systems in the Department of Electrical and Electronic Engineering.
Their objectives were two-fold: to flex their intellectual and technical muscles by designing a South African satellite and to fulfill their Stellenbosch University mission by producing employable graduates. The historical background of both those objectives should not be over-simplified or glossed over. South Africa overturned apartheid and established its democracy in 1994. Recognizing the need to continue developing world-class graduates, they chose space engineering as one of their initiatives. The fact that South Africa’s six major research institutions are in the top 1% of universities worldwide would explain the drive of the Stellenbosch faculty and students to undertake such an ambitious project.
Says Steyn,ÛThe students that worked on the SunsSat-1 satellite from 1991 to 1999 were all engineering students from Stellenbosch University and other SA universities doing their masters and PhDs in satellite engineering. About 5% of these students were from previously disadvantaged communities. We did, however, also enroll 50+ black BSc students in a Department of Communication sponsored program for a master’s degree and National Diploma in engineering during this time.Û
So, in addition to making strides in achieving racial diversity, the SunSat project was on the right track to connect research to application as would soon be recommended by Dr. Philemon Mjwara, Director General of the Department of Science and Technology: ÛÏThe South African system of innovation, its excellent universities, science councils and private sector players, has focused on basic research. What we’ve not done extremely well is to link research done at the universities with the needs of industry. ..Û
Stellenbosch University engineers reached out effectively to industry, Steyn says. ÛÏThe SA industry was interested in such a venture and also gave the necessary [financial] sponsorships to the students and the satellite.Û
In 1999, SunSat became the very first South African satellite to reach orbit, with a mass of 64 kg. The payload was a small, multispectral imager with a 15 m resolution operating from an altitude of 600 km. It was launched in February 1999 by NASA, which assisted and advised the South African group during the satellite development.
Steyn confirms,ÛSunSat-1 was operational for 2 years in orbit, until its battery failed due to an increase in temperature when the orbit changed over time to be constantly exposed to the sun. The human capital development and in-orbit successes and experience gained definitely made the whole program a huge success.Û
SunSpace Is Spun Off From Stellenbosch University
The success of SunSat fired up the Stellenbosch engineering group’s entrepreneurial spirit.
ÛÏSunSpace was established in 2001 to commercially exploit the satellite technology and expertise developed during the SunSat project,Û Steyn says.
The principals of SunSpace, also located in the city of Stellenbosch, are the same engineering group that developed SunSat at the university. Herman Steyn is manager of product development at SunSpace. Other principals include: Executive Chairman: Themba Vilakazi, Managing: Bart Cilliers, Business Development: Ron Olivier; and Bongani Caga, Christo Viljoen, Sybrand Grobbelaar, and Stellenbosch University Investment Trust Member: Arnold van Zyl.
ÛÏAs our commitment to long-term research and development can only be sustained by commercial application of space-based services, Sun Space Information Systems (Pty) Ltd (SunSpace in short) was incorporated by Unistel Group Holdings (Pty) Ltd, which is a company wholly owned by the university and which provides the opportunity to commercialize intellectual capital developed at the universityÛ_ SunSpace is a prime example of the role a university can play as a catalyst for economic growth,Û declares the SunSpace website.
Since then, SunSpace has deepened and expanded its portfolio. Steyn explains, ÛÏSunSpace successfully developed an Earth Observation minisatellite of 200kg, launched in April 2007 for an international client; this satellite is still fully operational and taking images on a daily basis. The client, for agreement reasons, cannot be named. The second satellite SumbandilaSat was built in less than 15 months in 2005 and 2006 and was ready for launch in December 2006.Û This launch was delayed until 2009 when the SumbandilaSat went into orbit.
As a result of this success, ÛÏSunSpace [has become] one of the leading players in a revolution in the global Earth observation (EO) satellite industry,Û wrote the trade journal, Engineering News.
Bart Cilliers, SunSpace managing director, told Engineering News: ÛÏIt’s a paradigm shift in satellite designÛ_It is comparable to the shift from mainframe computers to PCs a couple of decades ago.
ÛÏThis revolution is based on the continuing miniaturization of both electronic and optronic systems, which means that small EO satellites now have capabilities that once were the preserve of large satellites. And small satellites are much cheaper to design, build and launch, than large satellites. (Communications satellites are a completely different matter: their size is determined by the number of transponders they have to carry.)
ÛÏCoupled with this is the use of commercial off-the-shelf (COTS) components in the design and construction of satellites. Traditionally, every component that went into a satellite was specially designed and built for use in space. This greatly increased the cost, and the time, needed to build and test a satellite. It could take up to 15 years to develop and test this space-specific technology, so it was often obsolete before it first flew. COTS components have proved, however, to be extremely resilient and perfectly capable of handling the stresses and strains of launch and operation in space.Û
SumbandilaSat Is Built, Tested, and Launched
SumbandilaSat is a LEO (Low Earth Orbit) observation microsat with an Earth observation multispectral imager and other payloads designed to operate at an altitude of 500 km. The launch vehicle placed the ZA-002 SumbandilaSat spacecraft into a slight elliptical orbit of 490-510 km altitude. The Dept. of Science and Technology built, launched and commissioned the craft for $3.5M.
The main payload is a multi-spectral imager which has a 6.25m Ground Sampling Distance (GSD) at 500 km with 6 spectral bands and is supported by an on-board storage of 6 Gigabyte, with a redundant 18 Gigabyte spare. It has the capacity to record images of vegetation, plant vigor and stress, biomass, water bodies, silt in the water, roads and bare soil, among others.
The SumbandilaSat uses a standardized modular microsatellite bus. An unusual feature of the satellite is that a ground station operator, when the satellite is in the station’s field of view, can use the onboard TV cameras to monitor the boresight location to pick out objects to photograph, and then correct the satellite’s attitude accordingly with a simple joystick control input. This makes it possible to use the satellite to collect imaging data during a national emergency, for instance during floods, as well as to program pre-selected ground targets to image. The SumbandilaSat design and assembly approach made completion in a 15 month timeline possible and, therefore, presents a more affordable satellite program for developing countries.
The project was carried out in partnership with the Satellite Application Centre (SAC) at Hartbeeshoek near Pretoria. For the first few months after launch, SunSpace utilized the ground station at the Engineering Department of the University of Stellenbosch to commission and control the satellite, until SAC takes over the normal operations, telemetry, tracking, control and image data capturing. The Council for Scientific and Industrial Research (CSIR) will be responsible for its mission control ÛÒ receiving image data from the satellite and monitoring and controlling it to perform its various functions in orbit. This information is streamed to the SAC, which carries out the command and communications functions by tracking the satellite with a large dish antenna.
(SunSpace and the University of Stellenbosch published two papers about SumbandilaSat for further technical information, available online and cited at the end of this article: ÛÏA view finder control system for an earth observation satelliteÛ; and ÛÏSumbandilaSat—an operational technology demonstrator.Û)
The satellite’s experimental payload was open for use by educational institutions e.g. schools, universities, and also to the general public. Engineering IT reported this payload finally to include:
Û¢ SA AMSAT ÛÒ 2 m/70 cm amateur radio transponder and digitalker. This payload will find not only use by the amateur radio fraternity, but also has a large educational aspect of bringing space science into the class room.
Û¢ Software defined radio (SDR) experiment
Û¢ Architectural radiation experiment for commercial off-the-shelf devices (ARECOTS)
Û¢ A forced vibrating string experiment from Nelson Mandela Metropolitan University
Û¢ Very low frequency (VLF) radio experiment from the University of KwaZulu Natal.
For testing, SunSpace used the Denel space facilities at Houwteq, near Grabouw. Some of the tests on SumbandilaSat that were executed at Houwteq include vibration testing of the satellite to simulate the rocket launch phase, vacuum hot and cold testing to simulate the space environment and hot and cold cycling to identify early component failure and to verify workmanship in the manufacture of the satellite. To those in the business, this is known as ÛÏshake and bakeÛ.
The launch took place on September 17, 2009 at the Baikonur Cosmodrome in Kazakhstan. The satellite reached space on a Soyuz launch vehicle supplied by the Russian Roscosmos agency, and shared the launch vehicle with a primary payload, a Meteor-M weather satellite for Russia.
SA’s Next Generation of Satellite Engineers Also Launched
ÛÏThe technical component of the SunSpace workforce covers the complete required skill range from program management and systems engineering to detail design capabilities in electronics, software and mechanics,Û the company reports.
Diversity is still in the Stellenbosch/SunSpace mission. Steyn says, ÛÏSunSpace trained eight black engineering interns during the SumbandilaSat project and currently four of these engineers are employed by SunSpace.
A Reuter’s story gives a glimpse into the satellite’s daily operation. According to Microsatellite venture turns Soweto-born student into rocket engineer,
“The satellite passes over our ground station here in Stellenbosch about 4 to 5 times a day, and during each of those passes we have an opportunity to communicate with the satellite and during more or less a 10 minute window and during that 10 minute window we have to send up new commands to the satellite to program the satellite for specific modes or tasks that it has to execute and also have the opportunity to download telemetry data from the satellite during those same passes to make sure the health of the satellite is still ok,” explained Jan-Albert Koekemoer, the chief systems engineer at SunSpaceÛ_
“SumbandilaSat started off as a technology demonstrator but also at the same time, it had an internship running to build the space engineering and applications capacity in the disadvantaged and the black communities. Our goal for the SumbandilaSat is an ÛÏoutreach program where we are trying to get as many young black professionals, young black engineers, students, and not only black but also the entire South Africa, get them excited about this and also show them that we can work together towards making space a reality in our country,” added Khalid Manjoo, who helped to assemble SumbandilaSat.
ÛÏFor Jesse Ndaba, an electrical engineer at SunSpace, working on the project was a dream-come-true.
“It was just my interest, my dream, but I never thought it will materialize one day so when I saw an ad in the newspaper about the space internship, I just said well, this is designed for me, this is me, it’s just meant for me because this is what I’ve always wanted,” she said.
Waiting for SumbandilaSat Imagery in 2010
Meanwhile, SumbandilaSat is making two passes over South Africa every day. ÛÏSumbandila is currently being commissioned and many hi-res (6.25m GSD @ 6 spectral bands) have already been downloaded and analyzed for further calibration and performance improvement,Û says Steyn.
ÛÏNo images will be released, until the owner of the satellite, DST, has officially presented these to the media, only after the commissioning phase has been completed in early 2010,Û he adds.
1. Prof. WH Steyn interview December 10, 2009
2. Keith Campbell. SA space firm positions itself as low-cost, small satellite hub. Engineering News. 5th September 2008.
3. Willem H. Steyn, ÛÏA view finder control system for an earth observation satellite.Û Available online at www.sciencedirect.com
4. Silas Mosterta, Herman Steyn, Hendrik Burger, Helena Bosman. ÛÏSumbandilaSat—an operational technology demonstrator.Û Available online at www.sciencedirect.com
5. Sun Space and Information Systems (Pty) Ltd. http://www.sunspace.co.za/home/?url=/home
6. South African SmallSat SumbandilaSat Shipshape. SatNews. 10th December 2008.