Like your backyard telescope, just MUCH more powerful
In 2018, we’re launching the world’s biggest space telescope ever – the James Webb Space Telescope. Webb will look back in time, studying the very first galaxies ever formed. While Webb doesn’t have a tube like your typical backyard telescope, because it’s also a reflector telescope it has many of the same parts! Webb has mirrors (including a primary and a secondary) just like a small reflector telescope, only its mirrors are massive (6.5 meters across) and coated in gold (which helps us reflect infrared light).
How does a reflector telescope work? Light is bounced from the primary to the smaller secondary mirror, and then directed to your eye:
Webb works pretty much the same way!
Taking the place of your eye to the eyepiece is a package of science instruments, including cameras and spectrographs, which will capture the light directed into them by the telescope’s mirrors.
In order to install these instruments, we had to move the telescope structure upside down… an impressive sight!
Once Webb was in place on the assembly stand in the cleanroom, the team at Goddard Space Flight Center installed the instrument module (which we call the ISIM, or Integrated Science Instrument Module), with surgical precision. ISIM has four instruments, three of which were contributed by our partners, the European Space Agency and the Canadian Space Agency.
All four will detect infrared light from stars and galaxies as far away as 13.6 billion light years. In addition to seeing these first sources of light in the early Universe, Webb will look at stars and planetary systems being formed in clouds of dust and gas. It will also examine the atmospheres of planets around other stars – perhaps we will find an atmosphere similar to Earth’s!
Here is an image with the science instruments being lowered into their spot behind the primary mirror. You can see the golden mirror is face-down.
Here’s another perspective of the instruments being fit into the telescope.
What you’ve seen come together above is just the telescope part of the James Webb Space Telescope mission – next comes putting together the rest of the observatory. This includes our massive tennis court-sized sunshield (which acts like the tube-part of your backyard telescope, protecting the mirrors from stray light and heat), as well as the parts that do things like power the telescope and let us communicate with it.
It actually takes several weeks for Webb to completely unfold into its full deployment!
