On March 11, NASA’s James Webb Space Telescope team completed the critical mirror alignment steps and expects Webb’s optical performance will meet or exceed its science goals. It’s now ready to gather light from distant objects and deliver it to its instruments.
Thanks to its first-of-its-kind optical system, Webb will soon deliver its view of the cosmos.
“More than 20 years ago, the Webb team set out to build the most powerful telescope anyone has ever put in space and came up with an audacious optical design to meet demanding science goals,” says Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, in a statement. “Today we can say this design is going to deliver.”
Many of the largest ground-based telescopes on Earth use segmented primary mirrors, but Webb is the first in space with this design. Its 6.5 m primary mirror is made of 18 hexagonal beryllium mirror segments—too large to fit inside a rocket fairing. It had to be folded up to get it to space, and then unfolded in space before each mirror could be adjusted (within nanometers) to form a single mirror surface.
Beyond enabling the incredible science Webb will achieve, “the teams that designed, built, tested, launched, and now operate this observatory have pioneered a new way to build space telescopes,” says Lee Feinberg, Webb optical telescope element manager at NASA’s Goddard Space Flight Center, in a statement.
