The James Webb Space Telescope (sometimes called JWST) is an orbiting infrared observatory that will
complement and extend the discoveries of the Hubble Space Telescope, with longer wavelength coverage and greatly improved sensitivity.
The longer wavelengths enable the Webb telescope to look much closer to the beginning of time and to hunt for the unobserved formation of the first galaxies,
as well as to look inside dust clouds where stars and planetary systems are forming today.
| Proposed Launch Date: |
The project is working to a 2018 launch date. |
| Launch Vehicle: |
Ariane 5 ECA |
| Mission Duration |
5 - 10 years |
| Total payload mass: |
Approx 6200 kg, including observatory, on-orbit consumables and launch
vehicle adaptor. |
| Diameter of primary Mirror: |
~6.5 m (21.3 ft) |
| Clear aperture of primary Mirror: |
25 m2 |
| Primary mirror material: |
beryllium |
| Mass of primary mirror: |
705 kg |
| Mass of a single primary mirror segment: |
20.1 kg for a single beryllium mirror, 39.48 kg for one entire primary mirror segment assembly (PMSA). |
| Focal length: |
131.4 meters |
| Number of primary mirror segments: |
18 |
| Optical resolution: |
~0.1 arc-seconds |
| Wavelength coverage: |
0.6 - 28 microns |
| Size of sun shield: |
21.197 m x 14.162 m (69.5 ft x 46.5 ft) |
| Orbit: |
1.5 million km from Earth at L2 Point |
| Operating Temperature: |
under 50 K (-370 °F) |
| Gold coating: |
Thickness of gold coating = 100 x 10-9 meters (1000 angstroms). Surface area = 25 m2. Using these numbers plus the density of gold at room temperature (19.3 x 10-6 g/m3), the coating is calculated to use 48.25g of gold, about equal to a golf ball. (A golf ball weighs 45.9 grams.) |
