The James Webb Space Telescope is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about three months for the spacecraft to reach its destination, an orbit 940,000 miles or 1.5 million kilometers in space, called the second Lagrange Point or L2, where the spacecraft is balanced between the gravity of the Sun and the Earth.
Unlike Hubble, space shuttle astronauts will not service the James Webb Space Telescope because it will be too far away.
The most important advantage of this L2 orbit is that a single-sided sun shield on only one side of the observatory can protect Webb from the light and heat of both the Sun and Earth. As a result, the observatory can be cooled to very low temperatures without the use of complicated refrigeration equipment. These low temperatures are required to prevent the Webb's own heat radiation from exceeding the brightness of the distant cool astronomical objects.
Before and during launch, the mirror will be folded up. Once the telescope is placed in its orbit, ground controllers will send a message telling the telescope to unfold its high-tech mirror petals.
To see into the depths of space, the James Webb Space Telescope is currently planned to carry instruments that are sensitive to the infrared wavelengths of the electromagnetic spectrum. The new telescope will carry a near-infrared camera, a multi-object spectrometer and a mid-infrared camera/spectrometer.
The James Webb Space Telescope will be able to look deeper into the universe than Hubble because of the increased light-collecting power of its larger mirror and the extraordinary sensitivity of its instruments to infrared light. Webb's primary mirror will be at least 20 feet in diameter, providing much more light gathering capability than Hubble's eight-foot primary mirror.
The telescope's infrared capabilities are required to help astronomers understand how galaxies first emerged out of the darkness that followed the rapid expansion and cooling of the universe just a few hundred million years after the big bang. The light from the youngest galaxies is seen in the infrared due to the universe's expansion.
Looking closer to home, the James Webb Space Telescope will probe the formation of planets in disks around young stars, and study supermassive black holes in other galaxies.
Under the terms of the contract valued at $824.8 million, Northrop will design and fabricate the observatory's primary mirror and spacecraft. Northrop also will be responsible for integrating the science instrument module into the spacecraft as well as performing the pre-flight testing and on-orbit checkout of the observatory.
The Goddard Space Flight Center, Greenbelt, Md., manages the James Webb Space Telescope for the Office of Space Science at NASA Headquarters in Washington. The program has a number of industry, academic and government partners, as well as the European Space Agency and the Canadian Space Agency.
More information on James Webb Space Telescope is available at http://www.ngst.nasa.gov
