James Webb Space Telescope successfully passed final thermal vacuum test

NASA’s $8.8-billionJames Webb Space Telescope, the world’s largest and most expensive one, has successfully passed final thermal vacuum test, making its parts cleared for use in space. 
The 6.5-meter diameter telescope has 18 gold-coated mirrors and a tennis court-sized sun-shield to gather light and protect its instruments. The telescope set to launch in 2021. It took 20 years to build.

James Webb Space Telescope (JWST):
Operators: NASA / ESA / CSA / STScI
Mission duration: 5 years (design), 10 years (goal)
Launch date: March 30, 2021 (planned)
Launch mass: 6,500 kg
It is planned to be the successor to the Hubble Space Telescope.
It will provide greatly improved resolution and sensitivity over the Hubble and will enable a broad range of investigations across the fields of astronomy and cosmology.