The Giant Magellanic telescope (GMT) has just received a big slice of change to help develop and test advanced technologies that will give the future observatory such a clear view.
The National Science Foundation (NSF) of the United States awarded a $ 17.5 million grant to the GMTO Corporation, which is developing the GMT and will manage the large scope once it is up and running in the Chilean Andes in the late 1920s.
The money, the first to be awarded to the GMT project by NSF, “means the observatory will be important to the entire American astronomical community,” GMTO president Robert Shelton told Space.com.
“This award really allows us to accelerate our progress on critical components,”
The GMT will integrate seven 8.4-meter (27.6-foot) wide primary mirrors into a single light-collecting surface 80 feet (24.5 m) in diameter, three times wider than any optical telescope currently in operation. The large scope will also contain seven “adaptive secondary mirrors” (ASMs), each of which will be 3.3 feet (1m) wide and only 2mm thick, with hundreds of actuators attached to the rear.
“With those [actuators], we are able to bend this thin glass surface about 1,000 times per second, “GMTO project manager James Fanson told Space.com.” This is what we use to compensate for the distortion introduced by Earth’s atmosphere. Millisecond by millisecond, we measure the distortion and correct it, so that we can essentially remove the atmosphere above the telescope and get very sharp images. “
These extreme optics will give the GMT 10 times the resolving power of the famous NASA Hubble Space TelescopeGMT team members said. Astronomers will use GMT for a variety of high-impact projects, from hunting signs of life in the atmospheres of nearby exoplanets to probe the nature of dark matter and dark energy, which dominate the universe but remain largely mysterious.
However, doing all of this won’t be a walk in the park. For example, no other one-piece telescopic mirror is larger than a GMT primary segment. And the surface of all seven GMT primaries must be modeled almost to perfection: the margin of error is only 25 nanometers (1 millionth of an inch), about the width of a single glass molecule.
The seven segments also need to be “in phase” so that they align precisely and function as a single piece of hardware. The newly awarded NSF funds will help the GMT team demonstrate and practice just this way in two custom phased test benches, one at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, and the other at the University of Arizona in Tucson. . The grant will also allow the team to build and partially test an ASM.
The grant-funded work will take place over three years and will keep GMT on track for the “first light” in 2029, team members said. And the benefits will extend beyond GMT, Fanson said, noting that the technologies demonstrated will also be used by other telescopes in the future.
GMT development is going well overall, Shelton said, adding that the team hasn’t seen any major impact yet due to coronavirus pandemic.
Primary mirror segments 1 and 2 are completely finished and segment 3 is being polished at the University of Arizona’s Richard F. Caris Mirror Lab. Segments 4 and 5 are waiting to be refined and segment 6 will be launched in the coming months, Shelton said. (The Mirror Lab is doing all of this work, from casting to final polishing.)
In October 2019, the GMTO announced it had done so signed a $ 135 million contract with MT Mechatronics and Ingersoll Machine Tools to build and install the telescope mount, the 1,800-ton precision steel structure that will be the backbone of the GMT.
The mount is going through preliminary design review now, Shelton said.
“This is what we really need to focus on now, making sure the design meets our needs, because literally everything interfaces with the mount: the instruments, the mirrors, everything,” he said. “So that’s really the key right now.”
Mike Wall is the author of “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.