James Webb Space Telescope
The telescope's mirror is 6.5-meters in diameter, compared to Hubble's 2.4-meter mirror. It will observe from the Earth–Sun L2 Lagrange point, which is 1.5 million kilometers above the Earth. This point is well beyond orbit of the moon, which is 400,000 kilometers from the Earth.
A shield will allow the telescope to observe the infrared spectrum free from the interference of radiation from the Earth and Sun. The further away a galaxy is, the more redshifted its light becomes by the time it arrives. Webb's infrared capability means that it will be able to detect far older galaxies than Hubble is able to. It also allows the telescope to see threw dust clouds that obscured Hubble's view.
While the Hubble telescope was upgraded with a corrective lens in 1993 and additional cameras in 1997 and in 2009, the Webb telescope will be too far from Earth for repairs or upgrades.
The project's goals include study of the early universe, the life cycle of stars, the life cycle of galaxies, and planets beyond the solar system. The launch date has been delayed several times, but is currently scheduled for October 2021.
Unfolding the golden mirror wings of the Webb telescope.
- ↑ Webb Telescope Science Themes, NASA.