Cosmos
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By Cosmos
Work is progressing on the Giant Magellan Telescope, which, when built, will be the largest on Earth.
The latest progress report on the consortium’s website says the team has successfully installed the primary mirror into a support system prototype.
Barbara Fischer, the primary mirror subsystem manager for the Giant Magellan Telescope (GMT) says the primary mirror is potentially capable of delivering up to 200 times the power of today’s best telescopes, according to a press release issued by the not-for-profit GMT company.
The GMT is a collaboration between 14 different research institutions worldwide, including the Australian National University in Canberra, and is currently being constructed on the summit of Las Campanas mountain in Chile. It’s expected to be operational by the “early 2030s”.
The cost of the GMT is almost A$3.8bn (US$2.54bn). Consortium partners come from seven countries (Australia, Brazil, Chile, Israel, South Korea, Taiwan, and the United State) who have so far committed more than A$1.3bn (US$850m) with 60% coming from US-based members.
But the parts are being constructed and tested across 36 US states – with the primary mirror being installed at the University of Arizona’s Richard F. Caris Mirror Lab in Tucson – before it’s shipped to Chile.
The installation of the mirror, about half the size of a basketball court, will allow researchers to start a six-month “optical testing phase” to prove the capabilities of its light-collecting surface.
According to the website, the Giant Magellan Telescope (GMT) 368m2 light collecting surface is composed of seven of the world’s largest optical mirrors arranged in a flower pattern expected to provide “the highest image resolution over the widest field of view ever achieved”.
The support system prototype works with “nanometre precision” to adjust the mirror’s position, stabilise its temperature and maintain its shape by “mitigating mirror sagging from gravity as the telescope moves”.
“The Giant Magellan Telescope’s primary mirror active support system is the first of its kind,” says Trupti Ranka, a control systems engineer for the Giant Magellan Telescope.
“The active support system contains an array of approximately 200 actuators and sensors to control the position and shape of the 17-metric tons, 8.4-metre mirror within a fraction of a micron,” Ranka says, “the control system allows a harmonious operation between the sensor data and actuators to achieve this precision.”
The mirror will need to be carefully transported – each individual mirror component of the primary mirror weighs 17 tons and together contain three times the number of parts of a typical car – but once its installed, it’ll be protected by 300 static supports which lift the mirror against gravity, as well as dampers or shock absorbers, which mitigate movement of the glass.
There are about 6 earthquakes every month in Chile’s Atacama Desert. The mirror protection system will complement the GMT’s massive 65m tall earthquake-proof enclosure, which was greenlit for construction earlier this year.
Read more about the Magellan and other big telescopes
