When will the Webb telescope launch?

Webb is expected to launch in 2021.

What’s going on with Webb between now and launch?

Check out our timeline of events leading up to launch.

Will Webb replace Hubble?

No. Hubble will continue its mission until its parts give out to the point where it is no longer usable. The Webb and Hubble missions are expected to overlap, providing complementary science.

Will astronauts be able to repair Webb as they do Hubble?

Unlike Hubble, Webb is not designed to be serviced. Webb will be located at a much greater distance than Hubble, beyond the Moon instead of orbiting just above Earth. This is the reason that the nominal science mission length is 5 years with a 10-year goal. To insure the 5-year mission, NASA has engineered the observatory so that all critical subsystems are dual or will degrade gracefully with age. For instance, the Near Infrared Camera has two identical camera systems so that the optical quality can be maintained even if one were to fail.
Webb will also contain enough fuel for 10 years of maneuvers at its location. As with Hubble, Chandra, and Spitzer, the Webb science and operations center has the ability to change the operations of the observatory to maximize its scientific potential as it ages.

How long will Webb take to reach its location?

Webb will travel for about a month to reach its orbit at the Second Sun-Earth Lagrange Point.

When will we see the first images from Webb?

Webb will undergo science and calibration testing once it reaches its orbit, so regular science operations and the best images will begin to arrive around six months after launch. However, it’s normal to also take a series of “first light” images that may arrive slightly earlier.

What will Webb study?

Webb will study both the far and near universe, observing the infrared light emanating from its targets. It’ll look at planets and objects in our solar system, star clusters, nebulae, other galaxies, and the most distant reaches in the universe. Get a detailed look at what Webb will study.

Will Webb be able to see any visible light?

Yes. Although Webb’s focus is almost entirely on infrared light, it can also sense the red end of the visible spectrum (at wavelengths as short as 600 nanometers) — at better resolution than Hubble. Conversely, Hubble can see some infrared wavelengths, but Webb will see much more of the range of infrared light. Webb’s infrared vision will allow it to fill in the gaps in our knowledge of the universe caused by our limited ability to see infrared wavelengths.