James Webb Space Telescope (JWST or “Webb”)
The James Webb Space Telescope (JWST or “Webb”) is a joint NASA–ESA–CSA space telescope that is planned to succeed the Hubble Space Telescope as NASA’s flagship astrophysics mission. The JWST will provide improved infrared resolution and sensitivity over Hubble1, and will enable a broad range of investigations across the fields of astronomy and cosmology, including observing some of the most distant events and objects in the universe, such as the formation of the first galaxies.
Webb will be the largest, most powerful telescope ever launched into space. It follows in the footsteps of the Hubble Space Telescope as the next great space science observatory, designed to answer outstanding questions about the Universe and to make breakthrough discoveries in all fields of astronomy.
In this lifetime, we are entering another era of learning more about the Universe. The Hubble changed how we saw and understand the Universe around us. The Webb telescope will bring in the next unprecedented wave of information, and we are ready to blow our minds.
On Dec 25, 2021, the telescope is being launched on an Ariane 5 rocket from Europe’s Spaceport in French Guiana. From there it embarks on a month-long journey to its destination orbit around the second Lagrange point (L2), about 1,500,000 kilometres from Earth. In the first month after launch, Webb will unfold its sunshield, and then deploy its 6.5-metre primary mirror that can detect the faint light of distant stars and galaxies with a sensitivity a hundred times greater than that of Hubble.
Objects near this point can orbit the Sun synchronously with the Earth, allowing Webb to remain at a roughly constant distance and use a single sun-shield to block heat and light from the Sun and Earth. Unfortunately, the distance makes it impossible to do post-launch repair or upgrades. In the case of Hubble, the mirror had to be repaired later as it was wrongly fixed on launch.
ESA2 has a nicely done Webb Launch Kit (pdf) that details the telescope and the launch.
Hubble Space Telescope (Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA’s Great Observatories, along with the Compton Gamma Ray Observatory (1991–2000), the Chandra X-ray Observatory, and the Spitzer Space Telescope (2003–2020). The Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. ↩