The James Webb Space Telescope has fully deployed its sunshield on Tuesday, marking a critical milestone for the success of its mission to study every phase of cosmic history, NASA said in a statement.

The telescope's kite-shaped apparatus is 21 meters long and acts like a parasol; this ensures that the telescope's instruments are kept in the shade, allowing it to detect faint infrared signals from deep within the universe.

"This is the first time anyone has ever attempted to put a telescope this large into space," Thomas Zurbuchen, associate administrator for NASA's science mission directorate, said in a statement.

The telescope, being too large to fit into a rocket's nose cone, had to be transported folded. Its unfurling was a complex and challenging task, one of the most daunting NASA had attempted.

The James Webb is the successor to the Hubble. It blasted off on December 25, and is now more than halfway to its orbital point, which is 1.5 million kilometers from Earth.

Its infrared technology will allow it to study every phase of cosmic history and see the first stars and galaxies that formed 13.5 billion years ago.