James Webb Space Telescope nears completion

James Webb Space Telescope nears completion

On February 3 this year, technicians installed the 18th and final primary mirror segment on NASA's James Webb Space Telescope (JWST), an $8.8 billion observatory that's scheduled to launch in 2018 to investigate some of the biggest questions in astronomy.

The biggest-ever space telescope is now one major step closer to completion.

Each of the hexagon-shaped mirrors weighs 40 kg and spans 1.3 meters. After launch, the telescope will be flown to the second Lagrange point of the Earth-Sun system, about 1.5 million kilometers from Earth. From there, it will begin observations. When deployed in space, the telescope will have a 6.5-meter diameter.

Completing the assembly of the primary mirror is a very significant milestone and the culmination of over a decade of design, manufacturing, testing, and now assembly of the primary mirror system, said Lee Feinberg, optical telescope element manager at Goddard. There is a huge team across the country who contributed to this achievement.

Scientists and engineers have been working tirelessly to install these incredible, nearly perfect mirrors that will focus light from previously hidden realms of planetary atmospheres, star forming regions and the very beginnings of the universe, John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington, D.C., said in a statement.

JWST is billed as the successor to NASA's iconic Hubble Space Telescope. The new observatory features a much larger light-collecting surface than Hubble; with the 18 segments installed, JWST's primary mirror is 21.3 feet (6.5 meters) wide, compared to 7.9 feet (2.4 m) for Hubble.

Astronomers will also use JWST for a number of other purposes, including the search for possible signs of life in the atmospheres of relatively nearby alien planets.

James Webb Space Telescope nears completion