NASA’s James Webb Space Telescope, designed to give the world an unprecedented view of the early stages of the universe, arrived at its gravitational destination point in orbit around the Sun on Monday. about 1.6 million kilometers from Earth.
With a final course correction maneuver, performed by the onboard rocket boosters, the Webb reached a position of orbital stability between the Earth and the Sun, known as Lagrange Point Two or L2, a month after launch, NASA said.
The thrusters were activated by mission control engineers on the Space Telescope Science Institute in Baltimore, and the ground team used radio signals to confirm that Webb had successfully “inserted” into an orbital loop around L2.
From its vantage point in space, Webb will follow a special “halo” path in constant alignment with Earth, as the planet and the telescope circle the Sun in tandem, allowing uninterrupted radio contact.
By comparison, Webb’s predecessor, Hubble Space Telescope, 30 years old, orbits the Earth 547 kilometers away, passing in and out of the planet’s shadow every 90 minutes.
The combined pull of the Sun and Earth on L2 will hold the telescope firmly in place, so little additional thrust from the rocket will be needed to keep Webb from drifting, said Eric Smith, NASA’s program scientist for Webb.
The mission operations center has also begun fine-tuning the telescope’s primary mirror, a set of 18 hexagonal segments of gold-coated beryllium metal that measures 6.5 meters across, much larger than Hubble’s primary mirror.
Its size and design to operate primarily in the infrared spectrum will allow Webb to peer through clouds of gas and dust and observe objects at greater distances, and thus further back in time, than Hubble or any other telescope.
Several more months of work will be needed to prepare Webb for its astronomical debut.