The 26m diameter radio telescope at the South Africa's Hartebeesthoek Radio Astronomy Observatory (HartRAO) has been recommissioned following a major repair project. Built in 1960 as part of NASA's Deep Space Programme, the main bearing in the telescope's polar shaft failed in October 2008 and the telescope had to be shut down.
27 May 2010: HartRAO Associate Director for Space Geodesy Ludwig Combrinck surveying the 26m polar shaft before work begins, to determine its shift during the repair.
20 July 2010: The HartRAO 26m telescope drives for the first time with its new bearing, closely watched by technical staff.
The process to replace the bearing commenced in March 2010 and was successfully completed in July 2010. It involved building a structure to lift and stabilise the 200 ton telescope so that the old bearing, which lasted 48 years, could be replaced. All this had to be done about 12m above the ground. This was a significant engineering feat since it had only been done once before, on a sister NASA antenna in Spain.
"We are pleased that the HartRAO telescope is functional again. For many years this telescope has helped the South African and international astronomy community conduct world class research. In many ways it has been the pathfinder for our efforts to host the SKA through training South African radio astronomers, and it remains an important tool in our efforts to exploit South Africa's geographic position as an ideal place from which to conduct astronomy research. The fact that we successfully completed such a complex engineering project underwrites our ability to build and maintain the SKA." commented the Minister of Science and Technology, Ms Naledi Pandor.
The repaired Hartebeesthoek telescope was first driven on the new bearing on 20 July 2010, and the first test observations were made on 22 July 2010. This was followed by the first spectroscopic and pulsar observations on 23 July 2010, followed by the first operational 24-hour Very Long Baseline Interferometry (VLBI) observation session, linked with telescopes on other continents on 11 August 2010.
On 26 August 2010 HartRAO successfully re-joined the world of e-VLBI and contributed real-time e-VLBI fringes towards the electronic European VLBI Network (e-EVN). Thanks to a much higher data-rate connection, it was also the highest-rate real-time e-VLBI fringes ever from HartRAO. Data from the 26m antenna were fed at 896 Mbps to a VLBI correlator at the Joint Institute for VLBI in Europe (JIVE) at Dwingeloo in the Netherlands.
"It was a great moment for HartRAO when the telescope drove again on July 20. However, the real value of the repair has been shown by the previous users queuing up to use it as each observing capability has been tested, validated and made available in the recommissioning process," said Dr Mike Gaylard, Acting Managing Director at HartRAO.
"It's good to have you back! Congrats!"
- Dirk Behrend, Coordinating Centre Director, International VLBI Service for Astrometry and Geodesy (IVS), NASA
"Congratulations to HartRAO on fringes on their first IVS experiment with their new bearing! Welcome back."
- Ed Himwich, Network Coordinator, IVS Analysis Centre, NASA