The first mirror segment has finally been installed on the James Webb Space Telescope (JWST), marking a milestone in the construction of the next generation telescope. All the 18 segments should be in place by early 2016.
The JWST is the successor to the Hubble Space Telescope and will be able to look farther than its predecessor. It will be capable of observing the first stars in the universe as well as detecting the atmosphere and potential traces of life on exoplanets.
This week, the engineering team is using a robot arm to lift and carefully position the mirror segments, each measuring 1.3 meters (4.2 feet) across and weighing 40 kilograms (88 pounds).
The entire 6.5-meter (21-foot) primary mirror is composed of the 18 different hexagonal segments, which will give the telescope a collecting area of 25 square meters (269 square feet), which is five times the collecting area of Hubble.
Comparison between Hubble and JWST. NASA.
Each mirror is made of beryllium, an ultra-lightweight material, and coated in gold. They will be able to unfold and precisely align when the telescope reaches its position 1.5 million kilometers (1 million miles) from the Earth.
The largest feature of JWST is a tennis court-sized, five-layer sunshield, which protects the telescope from intense solar radiation. The telescope will be capable of seeing both visible and infrared light, and to perform at its best, the instrumentation needs to be kept very cold – under 50 Kelvin (-220°C, -370°F).
“After a tremendous amount of work by an incredibly dedicated team across the country, it is very exciting to start the primary mirror segment installation process,” said Lee Feinberg, James Webb Space Telescope optical telescope element manager, in a statement. “This starts the final assembly phase of the telescope.”
The JWST is a joint project between NASA, the European Space Agency (ESA), and the Canadian Space Agency. It will be launched in October 2018 from French Guiana on an ESA Ariane V rocket.
You can follow the progress of the mirror installation via a live webcam feed.