The James Webb Space Telescope (JWST) is nearing its final destination. But where is the observatory right now, and when will it finally come?
A joint collaboration between NASA, the European Space Agency and the Canadian Space Agency, JWST is the largest and most powerful space observatory ever built, and promises to revolutionize our understanding of the universe.
Unlike the groundbreaking Hubble Space Telescope, JWST will insert itself into an orbit around the sun at a special location known as the second Lagrange point or L2.
This point is located approximately 930,000 miles away from Earth in the exact opposite direction from the sun.
There are five solar-Earth Lagrange points - areas where the gravity of the sun and the earth balances the orbital motion of a given satellite.
By placing a spacecraft at any of these points, it can remain in a fixed position relative to the Earth and the sun, while using a minimal amount of energy - in the form of rocket shocks - to help it stay in place. . In essence, Webb will be locked in almost perfect harmony with the Earth's orbit around the sun.
The journey from Earth to L2 will take a total of 29 days. The telescope is currently 23 days inside this trip, after launching on December 24, 2021 from Europe's spaceport in the South American area of French Guiana.
According to NASA's James Webb tracker, the observatory has completed just over 91 percent of the distance to L2 at the time of writing, meaning it is currently located more than 821,000 miles from Earth in the direction of the second Lagrange point. The telescope is scheduled to arrive at L2 on January 23rd.
JWST covered most of this distance early in its journey, as it traveled at much higher speeds - since the observatory was separated from its launch vehicle, it began to slow down rapidly.
After the rocket that propelled Webb into space used up all of its fuel, the spacecraft essentially kissed L2 while being slowed down by the gravity of the Earth and the sun.
"As it no longer pushes (accelerates) away from the sun, gravity, as Webb feels, is the greatest force affecting its velocity," said Eric Smith, Webb program scientist at NASA's headquarters in Washington, DC. Newsweek.
"We've given Webb just enough launch speed to reach L2 but not shoot beyond it. Once it arrives at L2, its speed around the sun will balance the inward pull of the sun's gravity, putting us in a cycle of the sun. "