/ 21 May 2015

Small is big in the realm of satellites

Nanosatellites are relatively small
Nanosatellites are relatively small

Cubes, slightly smaller than loaves of bread, are the new manna in heaven, and are being launched into orbit in increasing numbers.

CubeSats are box-shaped versions of nanosatellites but, weighing between 1kg and 10kg, they are much lighter than traditional satellites, which can weigh anything up to a few tonnes.

Pretty much in the vein of cellphone handsets, satellites have also become smaller and better. They cost less but have the capability of bigger, older satellites.

In their short existence, nanosatellites have seen a remarkable uptake globally among universities and recent business start-ups. The exciting era of nanosatellites has begun.

Since 2000, more than 300 CubeSats have been launched, with the American start-up, Planet Labs, accounting for a third. It is expected that 3 000 nano- and micro-satellites will be launched over the next five years.

The cost of a big satellite can run into hundreds of millions of dollars, whereas a CubeSat can be built for about $100 000 and launched for much the same, depending on the complexity of the mission.

For this reason, CubeSats were initially used to train students for the aerospace industry. But now these small spacecraft can be used to track and trace aircraft and vessels at sea.

They can be launched into low Earth orbit and they pass over a specific geographical area more frequently than single big satellites.

This makes it possible for nanosatellites to be used for rapid responses to disasters, or to gather timely information for tele-medicine, environmental management and asset tracking.

They will soon even reach other planets.

With so many satellites big and small in orbit, there is the possibility (although still extremely small) of collisions with pieces of used rockets and defunct satellites floating about. But even tiny pieces of space debris are tracked with radar and potential collisions can be predicted and avoided with appropriate technologies.

This has inspired cutting-edge research and innovation, such as making sure nanosatellites de-orbit (return to the atmosphere and burn out) when they reach the end of their lives.

Combined with evolving national and international regulatory frameworks, future generations will continue to benefit from this resource.

On November 21 2013, South Africa made history by becoming the first African country to launch its own CubeSat, TshepisoSAT, into space.

It was developed by students and staff of the French South African Institute of Technology at the Cape Peninsula University of Technology with funding from the department of science and technology and the National Research Foundation.

TshepisoSAT was the first in a series of CubeSats that will study the ionosphere above Africa in collaboration with scientists of the South African National Space Agency and others on the continent.

Nanosatellites support the African Union’s science and technology ambitions, which it believes could reap massive benefits for the continent.

The African Union Science, Technology and Innovation Strategy for Africa 2024 (Stisa-2024) has six priorities, at the heart of which is the pursuit of space-based applications supported by an indigenous satellite industry. The priorities include putting an end to hunger, bringing about food security, and preventing and controlling diseases.

But establishing a sustainable African space industry faces a number of challenges, notably that of funding. Furthermore, young people are generally not rushing to take up careers in science, technology, engineering and mathematics.

Capacity building for the space industry is constrained by the high cost of traditional satellites and supporting infrastructure compared with other technologies.

Training and research
But CubeSats are winning over the youth to the space sector. By being cheaper to build and launch into space, they provide a cost-effective platform for training and research, especially for countries where a heavy investment in a space industry has to be weighed against more immediate needs such as health and welfare.

Combining the vibrant ingenuity and creativity of this generation with an equally ingenious and cool space technology can no doubt have a profoundly positive socio-economic effect on Africa.

Africa is steadily moving towards a coherent space programme and nanosatellites should be part of this broader strategy.

Pan-African constellations of nanosatellites can be developed in partnership with existing communities of excellence in science, engineering and mathematics on the continent.

By ensuring that Africa produces its own engineers and scientists, and by playing our part on the global stage, the continent will have taken another step towards the democratisation of space for its people.

Robert van Zyl is the director of satellite engineering systems at the Cape Peninsula University of Technology. This article was first published in The Conversation Africa. The Conversation