ハッブル宇宙天体観測所の寿命が切れると言う事で、次の宇宙天体観測所、ジェームス・ウエッブ宇宙天体観測所(JWST)が打ち上げられるという。その詳細は、
JWSTのWebサイトはこちら→JWST
しかし、その壮大さには驚かされる。地上150万Kmの軌道を周回という事なので、地球の大気による光や赤外線の吸収がないから、膨大な宇宙の新事実を明らかにしてくれることであろう。
otal payload mass: | Approx 6200 kg, including observatory, on-orbit consumables and launch vehicle adaptor. |
Diameter of primary Mirror: | 6.5 m (21.3 ft) approximately |
Clear aperture of primary Mirror: | 25 m2 |
Primary mirror material: | beryllium coated with gold |
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 - 28.5 microns |
Size of sun shield: | 21.197 m x 14.162 m (69.5 ft x 46.5 ft) |
Temp of sun shield layers: | Layer 1: Max temperature 383K = approx 231F Layer 5: Max temperature 221K = approx -80F Min temperature 36K = approx -394F |
Orbit: | 1.5 million km from Earth orbiting the 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 g/cm3), the coating is calculated to use 48.25g of gold, about equal to the mass of a golf ball. (A golf ball has a mass of 45.9 grams. Note mass does not equal size!) |