Going Ballistic

  • Huge and formidably powerful, the Russian Delta Class IV nuclear submarine will play a major role in the SumbandilaSat project.
  • Almost ready for launch. Having been thoroughly tested, the satellite is closed up and readied for its trip into space.
  • Propulsion unit
  • A reaction wheel, which helps to make adjustments to the satellite"â„¢s orientation.
  • Having consumed their best brains for a long time, SunSpace are ready to send their SumbandilaSat to Russia for launch. According to SunSpace"â„¢s Hendrik Burger, it"â„¢s been a labour of love. The R26 million microsatellite will orbit Earth at an altitude of 500 km.
Date:31 October 2006 Tags:, , , ,

It’s midnight, somewhere north of Murmansk. And something big is stirring…

Time: Nearly midnight, and counting the seconds. Place: An undisclosed location somewhere in the icy Barents Sea, north of Murmansk. Present: A Russian Delta Class IV nuclear-powered submarine extending the length of 1 football fields, and a Shtil 2.1 modified intercontinental ballistic missile. Event: The launch of South Africa’s second satellite into low-Earth orbit.

The R26 million SumbandilaSat (from “lead the way” in Venda) project has consumed a dedicated team of South African scientists, engineers and government officials for the best part of two years. The launch of the Department of Science and Technology’s 81 kg satellite, designed and built by Stellenbosch-based company SunSpace, will be a thoroughly satisfying finale to countless hours of intensive development and old-fashioned hard work.

It also represents the fruition of extraordinarily complex negotiations involving SunSpace, the Russian navy, the Russian space agency, South Africa’s Department of Science and Technology, various authorities in the United States, and countries along the flight path.

Think about it: a South African-built satellite is launched from a Russian nuclear submarine and carried halfway around the world aboard an ICBM before being released into low-Earth orbit over California. Twenty years ago, the very idea would have been preposterous. Today it’s simply another sign of changing times.

In essence, the sun synchronous satellite will give South Africa “affordable” access to space technology. Its 6-band onboard multispectral line-scan camera and video sensors, equipped with three different lenses, will scan the Earth at varying angles – 0,6 degrees (covering a 5 km area), 6 degrees (50 km view) and 50 degrees (about 500 km) – and transmit high-resolution images to a ground tracking station at the Hartbeeshoek Satellite Application Centre in Gauteng, with backup stations at Overberg Test Range, Bredasdorp and Stellenbosch University.

The satellite is equipped with 24 gigabytes of non-volatile memory, allowing it to stream about 6 GB of image data every day per unique located ground station. The images will enable scientists to monitor disasters such as fires, floods and oil spills, and deliver useful data on climate, dam levels, population density, crop yield and vegetation.

The SunSpace team will be very active in the first year, monitoring the performance of the satellite and ensuring the maintenance of its orbit, thereafter handing over control to the Satellite Application Centre at Hartbeeshoek.

Says Hendrik Burger, systems engineer in charge of SumbandilaSat: “There are so many factors to take into consideration for a project of this nature. For example, the drop zones for the launch debris – fuel tanks, cylinders, rocket motors – have to be calculated very carefully to avoid any risk of impacting built-up areas. The final stage (third stage rocket) will remain in orbit for a while before burning up on re-entry into the atmosphere.”

If all goes according to plan, SumbandilaSat will take to the sky during a 5-day launch “window” starting on December 20.

Why launch from a Russian submarine?

“Because their launch system is affordable and reliable. In this instance the Russian navy is providing a service for the Makeyev State Rocket Centre. They’re very professional… they know what they’re doing. That said, we’re pushing them in terms of the satellite release altitude of 500 km. They also had to adapt the submarine’s launch silo to accommodate our satellite.

“Of course, all agencies experience failures at some time or another – there is always a risk when you’re working with delicate equipment and small tolerances – but we are confident that we have done everything we can to achieve a successful orbit insertion. Once the craft is up there, we’ll be able to tweak its orbit with tiny, carefully calculated pulses from the onboard propulsion system – basically, a tank of butane with a valve and a nozzle – to ensure that it remains in place for at least the three-year lifespan of the project.”

The SunSpace team have enjoyed “excellent” co-operation from the Russians, according to Burger. “They’re friendly and helpful, and it’s obvious they want this to succeed just as much as we do.”

Exciting though it is, the new satellite is by no means the sole preoccupation of the SunSpace team. Says Burger: “We’re technical advisors to the South African government, which is collaborating with other countries on an African Resource Management (ARM) constellation of satellites that would include a 240 kg satellite, and perhaps an even bigger one. There are many facets to this work… expanding the benefits of space across the African continent, capacity-building, education, and much more. We’re taking the South African ‘can do’ mindset to a different level.”

Burger says their “baby” had to be built tough to withstand the rigours of launch, with its attendant vibration and formidable g-forces – not to mention the dramatic variations in temperature.

“In anticipation of this, we’ve designed and engineered the satellite with sufficient margin, duplicated critical circuits – for example, power and communications – and placed the various components in the most logical spots. Micrometeoroid or space junk impacts? There’s no way we can prevent that from happening. It’s just a question of odds.”

To maximise its chances of survival “out there”, the satellite is tested for the expected space environment. Vibration testing, thermal vacuum testing, electromagnetic compatibility testing and thermal cycling tests are carried out at the Institute for Space and Software Applications (formerly known as Houwteq) of the Department of Communications. Their testing facilities at Grabouw simulate the myriad stresses of launch and the final environmental conditions expected in space.

SunSpace is a privately owned company with extraordinarily good connections. Stakeholders include SunSat, the University of Stellenbosch, engineers and former Stellenbosch students, as well as a BEE component that helped to make it a leader in its field. Customers include organisations from Australasia, Europe, South America, South East Asia, the Middle East, and the governments of several developing countries – including South Africa. The University of Stellenbosch will be responsible for associated post-graduate training and scientific research in all aspects of satellite engineering.

Says managing director Bart Cilliers: “We at SunSpace are excited and grateful for the opportunity to partner with the South African government through DST to put our country in the lead in space in the African continent, while at the same time being able to train and excite nine gifted young people for the fledgling space industry.

“We see a strong partnership with government as the key to success in helping to meet its growth objectives for South Africa and Africa, as well as the key to lucrative exports to the rest of the developing world.”

Martin Jacobs, who handles new product definition and mission analysis at SunSpace, reckons South Africa’s long political and technological isolation helped to create a special breed of scientist. “We learned to think on our feet, to work within small tim

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