The Next Generation

The James Webb Space Telescope is the next chapter in spaced-based telescope astronomy. The Webb mission builds on the legacy of the Hubble Space Telescope’s powerful imaging capability and the Spitzer Space Telescope’s ability to detect light beyond the visible spectrum, into the mid-infrared range. Because infrared light travels through dense gas clouds that block visible light, Webb will reveal previously hidden regions of the universe: early galaxies, forming planets, brown dwarfs, and much more.

The largest telescope ever sent into space,

Webb’s innovative design tackles the two main challenges for an infrared telescope: it has to have a large mirror to best capture enough light; and it has to be kept cold to keep unwanted sources of infrared from interfering with the light being observed. Webb’s tennis court-sized sunshields protect it from stray heat and light from the Sun, while its large segmented mirror—18 segments covering 6.6 meters (21.6 feet) at its widest point—enables it to effectively capture infrared light.

The spectacular views of the heavens to be provided by this telescope and a deeper understanding of our universe and its origin are a worthy destination for this complex and challenging journey.

Forward, Report of the Next Generation Space Telescope Workshop, 1989

Launching such a large mirror into space was another huge challenge. The creative engineering answer? An origami-inspired folding telescope. Both the sunshield and the mirrors are designed to unfold after the telescope separates from its launch vehicle. This video simulates Webb’s journey to its orbiting position beyond the Moon, approximately 1 million miles from Earth.

…the scientific work feeds the technology and the engineers begin to make better spacecraft. That gives you better instruments and a better chance to go out to learn more.

James Webb, NASA Administrator, 1962

James Webb Space Telescope

Webb’s actual scientific observations are performed by four instruments, each specially designed to study different aspects of infrared light: the Near-Infrared Camera (NIRCam); Near-Infrared Spectrograph (NIRSpec); a Mid-Infrared Instrument (MIRI) with camera and spectrograph; and the Near-Infrared Image and Slitless Spectrograph (NIRISS).


These instruments include new technologies, like the microshutter array, that were developed for Webb to increase the telescope’s scientific capability and efficient operations throughout its mission. Both aspects are essential to Webb’s usefulness—efficiency allows more astronomers to make use of Webb while it is operational, and the best possible science capacity will help those astronomers investigate some of our most fundamental questions: How did we get here? How does the universe work?

Webb’s groundbreaking engineering will facilitate groundbreaking science. Learn more about the design and instruments that will enable the next generation of astrophysics discoveries.

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