Engineers grappling with SumbandilaSat glitches


Engineers at SunSpace are working to fix problems with South Africa’s second satellite, SumbandilaSat, which was damaged during a solar storm in early June. At the moment the satellite is not sending back images as it is in ‘safe mode’.

The power supply to SumbandilaSat’s onboard computer stopped responding to commands from the ground station, due to damage caused by solar radiation. According to Rob Olivier, Executive Director of Business Development at SunSpace, the power supply is still giving problems and the satellite is not sending back images. However, telemetry data is still coming through and engineers are trying to correct the satellite’s faults.

SunSpace engineer Niki Steenkamp could not say when the satellite would be functioning as normal but he hoped it would be sooner rather than later. One of the difficulties in fixing the satellite is that engineers are only able to reach it for 20-30 minutes a day due to its low Earth orbit (LOE), necessary for taking photos of Earth.

SumbandilaSat has been damaged by solar radiation before. Shortly after its launch in September 2009, radiation caused a power distribution failure that has rendered the Z-axis and Y-axis wheel permanently inoperable, meaning that the craft tumbles as it orbits and has lost the ability to capture imagery from the green, blue and xantrophyll spectral bands.

Olivier said that the reason for SumbandilaSat not having adequate radiation hardening was that there was not enough money for it and the satellite was built from commercial off-the-shelf (COTS) equipment. SumbandilaSat was, after all, intended only as a technology demonstrator. In this regard Steenkamp said the satellite has been an enormous success and has survived far longer than anticipated. ‘Priceless’ information and experience has been gained through the satellite, experience that can only comes from actually building and launching a satellite. Such experience will be utilised during the construction of future satellites.

Steenkamp said solar radiation is a real risk that is one of the leading causes of satellite failure. NASA has warned of future solar flares and other rough space ‘weather’, something that will create “further risks of anomalies” for SumbandilaSat.

Speaking about the most recent failure, Democratic Alliance’s Shadow Minister of Science and Technology Marian Shinn said, “What is disappointing about this [failure] is that it was not mentioned during the Science and Technology parliamentary portfolio committee’s oversight visit to the South African National Space Agency’s (SANSA’s) Space Operations at Hartebeeshoek on July 27.”

SumbandilaSat was developed by Sunspace at an estimated cost of R100 million. Earlier this year the Department of Science and Technology (DST) said that for every R1 invested in the SumbandilaSat programme, there has been a R6 return.

However, Raoul Hodges, centre manager at the Satellite Application Centre (SAC), said this is not a cash value, but it’s about the value for the social benefit of the country, considering the people involved, knowledge obtained and human capital investments. “You can’t really put a value to a picture. It’s the value taken from the picture in its use for disaster management, roads and transport. It’s not a physical, cash value.”

In response to a parliamentary question about the return on investment to the government for the costs associated with the SumbandilaSat, the DST said since the satellite is a technology demonstrator, the return on investment is in the form of human capital development in space science engineering; intellectual property and experience; and international cooperation in the field of space science and technology.

SumbandilaSat is South Africa’s second satellite, the first being SunSat, which was built by Stellenbosch University and launched by NASA in 1999. SumbandilaSat was built by local specialist company SunSpace at a cost of R26 million, and is owned by the DST. Although its imaging capacity is not has high as other satellites, it has succeeded in its primary stated mission of proving the viability of affordable micro-satellite technology, the DST says.

SumbandilaSat was launched from Kazakhstan in September 2009. It was originally scheduled for launch aboard a Russian naval submarine in 2007, but this fell through.

In March Cabinet approved the government’s move to acquire a majority stake in SunSpace. Minister of Science and Technology Naledi Pandor said the decision to buy shares in SunSpace is of strategic importance to the success of South Africa’s space programme.

According to Shin, Deloitte was to determine the size and cost of the shareholding by July this year. However, according to Bart Cilliers, Managing Director of SunSpace, the final report is due out at the end of this month, after which it will be presented to Cabinet.

Government’s shareholding in the company will be held by the South African National Space Agency (SANSA), which reports to the Department of Science and Technology.

The DST is planning to launch a constellation of satellites similar to SumbandilaSat in the next 10 to 15 years. One of these will be SumbandilaSat 2, which will be larger and more reliable than its predecessor.

More satellites will increase the availability of satellite data for a variety of applications, notably resource management and disaster monitoring. South Africa, Kenya, Nigeria and Algeria will participate in a joint venture and will eventually share in the data produced by the African Resource Management Constellation. In addition, South Africa hopes to build a space weather satellite with Brazil to monitor radiation over the southern Antarctic.

Olivier said that future satellites will benefit from experience gained from SumbandilaSat, especially with regard to radiation protection.