A key part of the James Webb Space Telescope passed a „health test,” the National Aeronautics and Space Administration said, a day after a camera failed aboard Hubble, the orbiting instrument it's slated to replace in 2013.
The „backplane,” a rigid structure that will form the spine of the James Webb Space Telescope (JWST), was tested in a vacuum in temperatures as low as minus 405 degrees Fahrenheit (minus 243 Celsius) for periods lasting two to three days from June to September, NASA said today in a statement. „We need it to hold steady while we're observing,” John Mather, senior project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in the statement. „These tests show that it will do that.”
The JWST will replace Hubble, the Earth-orbiting telescope whose launch in 1990 was dubbed by NASA as the most significant advance in astronomy since the 17th-century Italian astronomer Galileo Galilei's telescope. NASA said yesterday that Hubble's newest camera, which produced the deepest-ever view of the universe, has failed a month shy of its predicted lifespan.
Hubble's advanced camera for surveys (ACS), installed in 2002, produced the Ultra Deep Field images in 2003 and 2004 that showed multitudes of stars, including light from some that formed about 13 billion years ago, or just after the „big bang” many scientists say created the universe. Other Hubble lenses still work and can produce images. NASA vowed last year to upgrade Hubble's lenses and gyroscopes during a space shuttle mission in 2008 that will extend the telescope's life until 2013. Hubble is jointly operated by NASA and the European Space Agency.
„Until a solution, at least in part, can be found, Hubble will be returned to work with the remaining instruments,” ESA said today in an e-mailed statement. „At this time, it is expected that the main part of ACS will most likely not be restored.” NASA yesterday set up a so-called anomaly review board to investigate the failed camera. That board is scheduled to report findings and recommendations by March 2.
NASA and ESA are working with the Canadian Space Agency on Hubble's successor. The $825 million James Webb telescope, which is being built by Northrop Grumman Corp., is named for a former NASA administrator who ran the agency 1961 to 1968, helping guide US astronauts to the first moon landing in 1969. At 22 meters (72 feet) long, and the size of a two-story house, the JWST is bigger than Hubble.
Its main mirror is about seven times the size of Hubble's, enabling it to gather more light and look farther back in time. The JWST will operate mainly in the infrared light wavelength which can penetrate clouds of dust, while Hubble's observations have primarily been made in the ultra-violet and visible light portions of the spectrum.
„From the first light after the Big Bang to the formation of star systems that can support life on planets like Earth, the JWST will give scientists clues about the formation of the universe and the evolution of our own solar system,” NASA said. It „will explore many wonders in space - from distant galaxies to nearby planets and stars.” The new telescope won't orbit Earth as Hubble does; instead, it will occupy a so-called Lagrange point, a position in space 1.5 million kilometers from Earth where the instrument can remain fixed relative to Earth and the sun.
Its distance from Earth means that it won't be serviceable by shuttle flights, unlike Hubble, which is just 570 kilometers above the planet. The backplane of the telescope that was tested in freezing conditions is the largest structure ever to undergo such tests, NASA said. All of the JWST's parts - both structural components and software - will be „thoroughly tested” by engineers prior to launch, according to the agency. (Bloomberg)