NASA aced the most complicated, critical job on its newly launched space telescope Tuesday: unrolling and stretching a sunshade the size of a tennis court.

Ground controllers cheered and bumped fists once the fifth and final layer of the sunshield was tightly secured. It took just 1 1/2 days to tighten the ultra-thin layers using motor-driven cables, half the expected time.

The 7-ton James Webb Space Telescope is so big that the sunshield and the primary gold-plated mirror had to be folded for launch. The sunshield is especially unwieldly — it spans 70 feet by 46 feet (21 meters by 14 meters) to keep all the infrared, heat-sensing science instruments in constant subzero shadow.

FILE - In this April 13, 2017 photo provided by NASA, technicians lift the mirror of the James Webb Space Telescope using a crane at the Goddard Space Flight Center in Greenbelt, Md. (Laura Betz/NASA via AP, File) 

The mirrors are next up for release this weekend.

JAMES WEBB SPACE TELESCOPE UNFURLS SUNSHIELD IN MAJOR POST-LAUNCH MILESTONE 

The $10 billion telescope is more than halfway toward its destination 1 million miles (1.6 million kilometers) away, following its Christmas Day send-off. It is the biggest and most powerful observatory ever launched — 100 times more powerful than the Hubble Space Telescope — enabling it to peer back to almost the beginning of time.

FILE - This combination of images from a computer animation made available by NASA in December 2021 depicts the unfolding of the components of the James Webb Space Telescope. Webb is so big that it had to be folded origami-style to fit into the nose cone of the Ariane rocket. (NASA/Goddard Space Flight Center Conceptual Image Lab via AP)

Considered Hubble's successor, Webb will attempt to hunt down light from the universe's first stars and galaxies, created 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."

NASA'S JAMES WEBB SPACE TELESCOPE LAUNCHES DEEP INTO SPACE TO SEE 'DISTANT WORLDS' AND BACK IN TIME

Engineers spent years redoing and tweaking the shade. At one point, dozens of fasteners fell off during a vibration test. That made Tuesday's success all the sweeter, since nothing like this had ever been attempted before in space.

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