New space telescope reaches final stop million miles out
The world's biggest and most powerful space telescope has reached its final destination 1 million miles away
CAPE CANAVERAL, Fla. -- The world’s biggest, most powerful space telescope arrived at its observation post 1 million miles from Earth on Monday, a month after it lifted off on a quest to behold the dawn of the universe.
On command, the James Webb Space Telescope fired its rocket thrusters for nearly five minutes to go into orbit around the sun at its designated location, and NASA confirmed the operation went as planned.
The mirrors on the $10 billion observatory still must be meticulously aligned, the infrared detectors sufficiently chilled and the scientific instruments calibrated before observations can begin in June.
But flight controllers in Baltimore were euphoric after chalking up another success.
"We’re one step closer to uncovering the mysteries of the universe. And I can’t wait to see Webb’s first new views of the universe this summer!” NASA Administrator Bill Nelson said in a statement.
The telescope will enable astronomers to peer back further in time than ever before, all the way back to when the first stars and galaxies were forming 13.7 billion years ago. That's a mere 100 million years from the Big Bang, when the universe was created.
Besides making stellar observations, Webb will scan the atmospheres of alien worlds for possible signs of life.
“Webb is officially on station," said Keith Parrish, a manager on the project. “This is just capping off just a remarkable 30 days."
The primary mirror has 18 hexagonal segments, each the size of a coffee table, that will have to be painstakingly aligned so that they see as one — a task that will take three months.
“We’re a month in and the baby hasn’t even opened its eyes yet,” Jane Rigby, the operations project scientist, said of the telescope's infrared instruments. "But that's the science that we’re looking forward to.”
Monday's thruster firing put the telescope in orbit around the sun at the so-called second Lagrange point, where the gravitational forces of the sun and Earth balance each other. The 7-ton spacecraft will loop-de-loop around that point while also circling the sun. It will always face Earth’s night side to keep its infrared detectors as frigid as possible.
At 1 million miles (1.6 million kilometers) away, Webb is more than four times as distant as the moon.
The Webb is expected to operate for well over a decade, maybe two.
Considered the successor to the Hubble Space Telescope, which orbits 330 miles (530 kilometers) up, Webb is too far away for emergency repairs. That makes the milestones over the past month — and the ones ahead — all the more critical.
Spacewalking astronauts performed surgery five times on Hubble. The first operation, in 1993, corrected the telescope's blurry vision, a flaw introduced during the mirror's construction on the ground.
Whether chasing optical and ultraviolet light like Hubble or infrared light like Webb, telescopes can see farther and more clearly when operating above Earth's distorting atmosphere. That's why NASA teamed up with the European and Canadian space agencies to get Webb and its mirror — the largest ever launched — into the cosmos.
James Webb telescope parked in observing position
Thirty days after it was launched, the James Webb telescope has arrived at the position in space where it will observe the Universe.
The Lagrange Point 2, as it's known, is a million miles (1.5 million km) from Earth on its nightside.
Webb was finally nudged into an orbit around this location thanks to a short, five-minute thruster burn.
Controllers back on Earth will now spend the coming months tuning the telescope to get it ready for science.
Key tasks include switching on the observatory's four instruments, and also focusing its mirrors - in particular, its 6.5m-wide segmented primary reflector.
"There's a pretty intensive effort to take all of those 18 segments from their current state and get them to act as one big mirror, and also to get the secondary mirror into its optimised condition," explained Charlie Atkinson, the chief engineer on Webb at Northrop Grumman, the American aerospace company that co-led the telescope's development with the US space agency (Nasa).
"We do this using the science images, which is why we need to get the science instruments activated and checked out with some initial calibration work," he told BBC News.
Webb, billed as the successor to the famous Hubble Space Telescope, was launched on 25 December by an Ariane-5 rocket from French Guiana.
Its overarching goals are to take pictures of the very first stars to shine in the Universe and to probe far-off planets to see if they might be habitable.
Europe's Ariane-5 gave the new observatory a near-perfect trajectory and velocity to get it out to L2. Even so, two course correction burns were necessary, with the third on Monday tipping Webb into its planned parking position.
The Lagrange Point 2 is one of five gravitational "sweet-spots" around the Sun and Earth where satellites can hold their position with few orbital adjustments, thus conserving fuel.
The other advantage is that Webb will not experience at L2 the big swings in temperature and light endured by space telescopes positioned much closer to Earth.
This is vital for the mission. It's designed to view the cosmos in infrared light and must maintain therefore constant super-cold conditions for its hardware.
Infrared light has waves that are just longer than those of visible light. "Seeing" in the infrared will allow the telescope to, for example, look through dust to image stars that would otherwise be obscured.
Webb will now circle L2, keeping the Earth and the Sun in a near-straight line.
"L2 is pseudo-stable," said Jean-Paul Pinaud, who leads the Northrop engineers that keep Webb on track.
"The flight operations team is preparing routine station-keeping burns. They'll be doing those every 20 days or so with the trajectory calculations provided by our flight dynamics team. We'll set them up in a similar way, and then fire the thruster. But the burns will be quite small."
Hidden behind a big sunshield, Webb's optics and instruments will soon cool to about -230C (some sections of the telescope are already there). When that happens, controllers will switch on Webb's Near Infrared Camera (NIRCam) to take a picture of a test star to begin the process of aligning the big mirror.