The South African National Space Agency (Sansa) and its Russian counterpart, Roscosmos, hope to sign the agreement on South Africa becoming a member of the Russian-led international space radio telescope Radioastron programme this month. In addition, Sansa has also proposed a comprehensive cooperation agreement to Roscosmos.

The conclusion of the Radioastron agreement has been delayed by various administrative obstacles, including changes in Russian regulations concerning space cooperation. These required a degree of renegotiation of the agreement. As this is a bilateral accord, it is likely to be signed before, and separately from, the upcoming Brazil Russia India China and South Africa (better known as BRICS) summit, being hosted by South Africa.

The Radioastron mission is led by the Astro Space Centre of the Lebedev Physical Institute of the Russian Academy of Sciences. The other participants in the programme are Australia’s Commonwealth Scientific and Industrial Research Organisation, the European Space Agency, Finland’s Helsinki University of Tech- nology, India’s Tata Institute for Fundamental Research and the US’ National Radio Astro- nomy Observatory.

The Radioastron spacecraft was launched in 2011 and is equipped with a 10 m diameter radio telescope dish. With a mass of 3.8 t, Radioastron is the biggest radio telescope in space. It has a highly elliptical orbit, with a perigee (point closest to the earth) of about 10 000 km and an apogee (point furthest from earth) of some 350 000 km, which takes it almost as far as the moon (the moon’s average distance from earth is 384 400 km). It takes eight days and seven hours to execute one orbit of the earth.

The Radioastron spacecraft was designed and built by the Lavochkin Association and is based on the company’s Spectr-R satellite. Lavochkin – which gained fame for its fighter aircraft for the Red Air Force during the Second World War – today specialises in satellites and interplanetary space probes and is also responsible for the Fregat upper stage rocket.

Radioastron is expected to have an operational life of at least five years and complements the American Hubble Space Telescope, which is an optical telescope.

Radioastron’s radio telescope will be operated in conjunction with ground-based radio telescopes in a space very long baseline interfero- metry (VLBI) programme that will focus on the centimetre and decimetre wavelength bands.

Interferometry is the use of several radio telescopes in different locations to simultaneously focus on and image the same object in the sky. The signals received by each dish are fed into a computer and because the dishes are not in exactly the same place, the distance travelled by the signals to each is not identical and combining them creates an interference pattern that can be analysed by computer to provide high-resolution images of celestial objects.

The baseline is the distance on the earth’s sur- face between the telescopes, and VLBI involves the use of telescopes in different continents and indeed in different hemispheres. The more telescopes involved and the longer the baseline, the greater the resolution that can be achieved. With space VLBI, a space telescope is connected with terrestrial instruments to create huge baselines.

Meanwhile, a proposal for South Africa to host a ground laser station for the Russian satellite navigation system, Glonass, has been postponed. This will be discussed at a later stage.

Currently, the only formal agreement in force between Sansa and Roscosmos covers remote sensing of the earth. This is why the South African agency would like to negotiate a comprehensive cooperation agreement, covering all aspects of space science and technology. In addition, it is known that the development of bilateral space cooperation between the two countries is being driven from the highest political level in each country.