Webb Telescope Program Does Well; Hubble Spots Likely Dark Matter
The James Webb Space Telescope (JWST) is proceeding well, with some components ahead of schedule, and the next-generation eye in the sky is set for a 2013 launch on a mission to see if there may be other planets supporting life in the universe.
JWST may be able to spot the birth of stars and planetary systems similar to ours, witnessing events billions of years ago.
All 10 new technologies for JWST are sufficiently mature so they can move into detailed engineering, space journalists were told.
That was the message from leaders of NASA and Northrop Grumman Corp. [NOC], the JWST prime contractor, in a briefing beneath a full-scale model of the JWST on the National Mall in Washington, where briefers explained how JWST will push the boundaries of astronomy.
Briefing were Edward Weiler, director of Goddard Space Flight Center in Greenbelt, Md.; Matt Mountain, director of the Space Telescope Science Institute in Baltimore; and Martin Mohan, the Northrop Webb Telescope program manager.
That briefing came as the predecessor to the JWST, the Hubble Space Telescope, found further evidence that dark matter exists. NASA experts are expected to brief on the finding at 1 p.m. ET tomorrow. To tune in, please go to http://www.nasa.gov/newsaudio on the Web. At the start of the briefing, images and supporting graphics will be posted at: http://www.nasa.gov/mission_pages/hubble/news/dark_matter_ring.html on the Web.
NASA termed the Hubble findings “the strongest evidence to date that dark matter exists.
“This evidence was found in a ghostly ring of dark matter in the cluster CL0024+17, discovered using NASA’s Hubble Space Telescope. The ring is the first detection of dark matter with a unique structure different from the distribution of both the galaxies and the hot gas in the cluster.”
For more on this, see the June 20 issue of Astrophysical Journal.
At the JWST news conference, briefers described how the JWST mirror is so large, several Hubble mirrors could fit inside it. The folding mirror, 20 feet wide, boasts 18 hexagonal segments made of beryllium to save pounds. Otherwise, the mirror would be stupendously heavy.
The surface of the mirror must be so smooth it can’t vary by even 1/2000th the thickness of a human hair, so that pictures won’t be blurry.
A multi-layered shield, looking like so many parallel canvas tarps stretched taut, will shade the JWST from the heating rays of the sun, so that the telescope can keep its cool and operate at a temperature that keeps its infrared sensors in working shape: a brisk 370 degrees below zero. Cryocoolers will help keep the heat down, as well.
The sunshielding layers will keep all but about 1 millionth of the light from the sun from striking the JWST.
It will be well beyond any problematical light radiance from Earth, hovering 940,000 miles out. That’s about four times the distance from Earth to the moon, though it is only about 1 percent the distance from Earth to the sun.
But the long trip is worth it. JWST will be able to see far fainter light than other telescopes.
Aside from NASA and Northrop, Other participants in the JWST program include Lockheed Martin Corp. [LMT], the Jet Propulsion Laboratory, and the University of Arizona.
While astronauts won’t be able to service the JWST as they can the Hubble, the JWST will have a small ring attached to it, so that astronauts on the next-generation spaceship, Orion, will be able to go to the JWST if it needs minor adjustments.