(By NASA’s James Webb Space Telescope – https://www.flickr.com/photos/nasawebbtelescope/51774831484/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=113644760)
Did you know today is Isaac Newton’s birthday? Happy Newtonmas!
The James Webb telescope is going to see galaxies so far away their light has been shifted into the infrared. This will enable us to view the universe at just a couple hundred million years after the Big Bang.
It will be launched to the L2 LaGrange point, a million miles farther from the sun from the Earth. This is one of the LaGrange points, positions where a satellite will “stay put” relative to Earth. It will cycle around that point, always staying the same distance and not wander off into an independent orbit. A sun-shield the size of a tennis court will keep the sensors cool. They have to be cooled to 7 degrees above absolute zero to keep the thermal noise down. Webb sees in the infrared while Hubble, which sees in visible light, does not need such cooling.
https://en.wikipedia.org/wiki/James_Webb_Space_Telescope
Webb will be so far out there is currently no capability to repair it. Hubble has been repaired by humans twice in its history. It is likely that some method could be improvised should it be needed but that depends on exactly what went wrong. Not everything can be repaired. The mission is expected to last 6 years. This observatory has been in development since 1996 and cost $10 billion to produce, not including launch and tracking costs. Even forgetting all that, given the science it will produce I think it would be a terrible shame not to do everything possible to keep it alive and extend the mission indefinitely.
In the meantime, just enjoy it for being the amazing thing that it is. When the world’s nations put their brightest minds to it there is nothing humans can’t do. It still has a long and perilous road ahead (“29 days on edge”) until it reaches station. Assuming no major glitches happen, it is probably our greatest space achievement since the Apollo landings.
December 27, 2021 at 05:16
He’ll yeah! Did some undergrad work in infrared with the FLAMINGOS K band detector on the Mayall 4 meter at Kitt Peak. Took a lot of processing and wasn’t great.
December 26, 2021 at 08:12
Another commentator was saying that Webb will not arrive at L2 until about Jan 24, 2022. Along the way, it must perform some very intricate unfolding and startups, most of them critical and beyond repair. Now the real nail biting begins!
https://jwst.nasa.gov/content/webbLaunch/deploymentExplorer.html
December 25, 2021 at 23:44
That is awesome to know.
December 25, 2021 at 11:22
L2 is located about four times further away from the Earth than the Moon ever gets, and it orbits the Sun at the same rate as the Earth. Lagrange discovered that there are 5 points, dotted around the two larger masses, in which all the forces acting on the small one would cancel out. These have become known as Lagrangian points L1 through L5.
December 25, 2021 at 11:10
In celestial mechanics, the Lagrange points are points near two large orbiting bodies. Normally, the two objects exert an unbalanced gravitational force at a point, altering the orbit of whatever is at that point. Lagrange points are positions in space which allow objects that are sent there, to stay put. At Lagrange points, the gravitational pull of two large masses precisely equals the centripetal force required for a small object to move with them. These points in space can be used by spacecraft to reduce fuel consumption needed to remain in position. The James Webb Space Telescope is being sent into a gravitationally stable position known as L2, where the telescope will orbit the sun and remain roughly a million miles from Earth on the opposite side of our planet from the sun. The L2 point of the Earth-Sun system was the home to the WMAP spacecraft, current home of Planck, and future home of the James Webb Space Telescope. L2 is ideal for astronomy because a spacecraft is close enough to readily communicate with Earth, can keep Sun, Earth and Moon behind the spacecraft for solar power and (with appropriate shielding) provides a clear view of deep space for our telescopes. The L1 and L2 points are unstable on a time scale of approximately 23 days, which requires satellites orbiting these positions to undergo regular course and attitude corrections.