Webb Telescope preps for deep-space research
The James Webb Space Telescope is set to peer further into space than Hubble ever could
The biggest space telescope ever created has captured its first photons of starlight. NASA officials last Friday announced that all 18 segments of the James Webb Space Telescope’s giant mirror seemed to be functioning properly. The massive observatory also snapped a selfie to send back to Earth, along with light signals from the constellation Ursa Major.
“That was just a real wow moment,” said Marshall Perrin of the Space Telescope Science Institute in Baltimore.
The Webb Telescope is moving into the final stages of preparation before it is scheduled to begin regular observation in June, sending batches of galactic photographs back to Earth. The large spacecraft represents a new phase in space exploration: NASA has dubbed it a successor to the long-operating Hubble Space Telescope. Webb’s cutting-edge technology could open a window into deep space, but the team operating the telescope still has obstacles to overcome before the mission comes fully into its own.
The telescope was launched from French Guiana on Christmas Day 2021 and reached its orbit around the sun 1 million miles from Earth in January. The $10 billion project started two decades earlier, the culmination of the work of hundreds of scientists and organizations, thousands of engineers, and three international space agencies. NASA partnered with the European Space Agency and Canadian Space Agency to build the telescope, named after former NASA administrator James E. Webb, who led the U.S. space agency through the Apollo program.
The Hubble Telescope, closely orbiting Earth, launched more than three decades ago and has contributed to thousands of scientific papers. The smaller, aging Hubble likely still has years of research left in it—astronauts can carry out regular maintenance—but it won’t last forever.
Webb isn’t a mere replacement of Hubble, whose famous photographs capture the universe in optical and ultraviolet wavelengths. The new telescope’s much-larger mirrors can look deeper into space and will primarily collect infrared data, allowing it to observe the interior of nebulae more closely. Webb will be able to study formations astronomers say formed early in the universe’s history: early stars, black holes, and more. Scientists hope the images will lead to greater understanding of the origins of our solar system, according to NASA.
Webb’s 21-foot, gold-plated mirror is the largest ever launched into space. It is made up of 18 hexagons that were folded up for launch and have spent the past few weeks carefully opening, cooling down, and aligning. That process is precise and tricky: Now that Webb has captured its first image, the team on the ground can use it to ensure the observatory’s mirrors are aligned properly. Additionally, the team has to confirm the mirrors don’t contain flaws that could affect the images the telescope returns to Earth.
After Hubble launched in 1990, NASA identified a problem with its mirrors that caused it to return blurry images. The agency sent astronauts on a spacewalk three years later to fix the issue, but that won’t be possible if something goes wrong with Webb: Because it orbits the sun, not the Earth, it is 1 million miles away, and any adjustments will need to be made by relaying instructions from Earth. Engineers should be able to rule out any flaws by next month, said Lee Feinberg, Webb’s optical telescope element manager at NASA’s Goddard Space Flight Center.
The team carefully chose the telescope’s orbit, which keeps it almost in line with the Earth and the sun, allowing constant communication with the observatory. A solar array powers the observatory with 2,000 watts of energy, and a supply of propellant serves for course correction and other needs. NASA officials say the observatory has enough fuel to keep at its job for up to 20 years. It could release test images from Webb as soon as this spring.
“We are planning a series of ‘wow’ images to be released at the end of commissioning when we start normal science operations that are designed to showcase what this telescope can do,” said Jane Rigby, a Webb mission scientist at Goddard, said at a January news conference. “They will really knock everybody’s socks off.”