NASA’s James Webb telescope, the largest and the most powerful space telescope, unfolded its golden mirror for the last time on Earth. The $10 billion observatory successfully completed the pre-launch test and will be launched in October this year.

The telescope has a 21 feet 4 inches mirror that was fully expanded and locked as a part of the test, NASA said. The final test was to ensure that the telescope survives its 1.6 million kilometers-long journey to discover the origins of the cosmos.

“It’s like building a Swiss watch at 40-feet-tall… and getting it ready for this journey that we take into the vacuum at minus 400 degrees Fahrenheit (-240 Celsius), four times further than the Moon,” said Scott Willoughby of lead contractor Northrop Grumman.

Floating piece of origami

The giant mirror on the James Webb telescope is made of 18 hexagonal segments that have an ultra-thin layer of gold to improve its reflection of infrared light. It will have the ability to fold each mirror into a specific position, allowing it to fit in a 16-foot rocket fairing. These mirrors will come together to form a massive reflector and allow the telescope to look for places in the cosmos that were unexplored before.

Astronomers want to use the telescope to understand how the first star and galaxies were formed, a few hundred years after the Big Bang. For this, they will need to detect infrared, which is not possible with the Hubble telescope, which has limited infrared capacity.

Unraveling origins of the universe

This is important because by the time the light from the first objects reaches our telescopes, it shifts towards the red end of the electromagnetic spectrum. This happens due to the constant expansion of the universe.

The telescope will also aim to find alien life in the cosmos. For the first time in the 1990s, planets that orbit other stars were discovered. Now, there are more than 4,000 exoplanets that have been confirmed.

The new telescope “has instrumentation that will propel this new and exciting field into its next epic of discovery,” said Eric Smith, program scientist of the James Webb telescope. The space observatory will be available to scientists from 44 countries.