The 20-metre telescope gets a new radome

On 12th August work began on replacing the radome which surrounds and protects the 20-metre telescope at the Onsala Space Observatory, Chalmers.
Two weeks on it was time for the exciting moment when the new cap, made up of 50 of the radome’s total 620 triangular panels, was installed.

The 20-metre telescope has been used for observations in radio astronomy and geoscience from as far back as 1976. It is still often used by scientists, but its 38 year old protective shell had begun to show signs of age.

A complicated operation
So it was time to renew the telescope’s protective covering, comprising 620 triangular panels of glass-fibre reinforced plastic. A complicated operation, and one dependent on favourable weather conditions.
The 50 panels positioned on the top of the big white football have now been successfully replaced. The total weight of these panels is two tons.
‘Over the next eight weeks the remaining 570 panels will be replaced one at a time,’ explained Hans Olofsson, professor of radio astronomy at Chalmers, supervising the radome replacement project.

Attracts thousands of visitors
Onsala Space Observatory lies in north Halland, 45 km south of Göteborg. The mysterious white ball is a familiar landmark in the area and attracts thousands of visitors each year.
The radome upgrade is the most visible change that has happened at the observatory since its part of the giant telescope Lofar was built here in 2011.
In two of these pictures, the Lofar station is visible beyond the open radome.

54 meter high crane
The panels were lifted into place with a green, 54 meter high crane. During this operation the dish of the 20 meter telescope was redirected in order to protect it when work was being carried out on the various parts of the radome.
Much of the work was done by a team from Essco, the same US company that installed the original radome when the telescope was first built. The work is expected to extend into October. Since 12th August, the team have been installing the new panels one at a time. Now the new cap is in position, they will continue this process until all 620 panels have been replaced.

Text: Robert Cumming and Michael Nystås
Photo: Peter Widing, Robert Cumming, Lars Wennerbäck and Roger Hammargren

To see more pictures of the radome replacement visit Flickr >>>

Facts about Onsala Space Observatory
Onsala Space Observatory, the Swedish National Facility for Radio Astronomy, provides scientists with equipment to study the Earth and the rest of the Universe. We operate several radio telescopes in Onsala, 45 km south of Göteborg, and take part in international projects. The observatory is a geodetic fundamental station.

Two radio telescopes are operated along with a station in the Lofar telescope network, along with equipment for GNSS, ocean level measuring, gravimetry, seismology and atmosphere research. The Observatory participates in several international projects. It is hosted by the department of Earth and Space Sciences at Chalmers and operated on behalf of the Swedish Research Council.

The observatory is now building a new tide gauge station to complement the observatory’s GNSS tide gauge, which measures ocean levels using signals from GPS satellites.

The Onsala Twin Telescope, two 12 meter antennas that will be used to measure the Earth’s movements, is to be built in 2015.
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