Trickiest task on newly launched James Webb Space Telescope nailed by NASA

On Tuesday, NASA completed the most difficult and crucial task on its freshly launched space telescope: unrolling and stretching a tennis-court-sized sunshade.

Once the fifth and final layer of the sunshield was properly secured, ground controllers applauded and bumped fists. The ultra-thin layers were tightened in just 1 1/2 days using motor-driven wires, which was half the time expected.

The sunshield and primary gold-plated mirror of the 7-ton James Webb Space Telescope had to be folded for launch due to their size. The sunshield is particularly cumbersome, measuring 70 feet by 46 feet (21 metres by 14 metres) in order to keep all of the infrared, heat-sensing research instruments in permanent subzero darkness.

This weekend will see the release of the mirrors.

Following its Christmas Day launch, the $10 billion telescope is more than halfway to its 1 million-mile (1.6-million-kilometer) objective. It is the world's largest and most powerful observatory, 100 times more powerful than the Hubble Space Telescope and capable of seeing back to practically the beginning of time.

Webb, who is seen as Hubble's successor, will seek out light from the universe's first stars and galaxies, which formed 3.7 billion years ago.

"This is a really big moment," project manager Bill Ochs told the control team in Baltimore. "We've still got a lot of work to do, but getting the sunshield out and deployed is really, really big."

Engineers reworked and tweaked the shade for years. During one vibration test, dozens of fasteners came loose. That made Tuesday's triumph more sweeter, because nothing like this had ever been attempted in space before.

"First time and we nailed it," engineer Alphonso Stewart told reporters.