The most prolific space telescope in history is heading toward a final curtain call.
Earlier this month, NASA announced its replacement for the successful Hubble Space Telescope, which is scheduled to end its mission in 2010 when its successor, the James Webb Space Telescope, is slated to launch. Its mission'like Hubble's'is to help answer humanity's largest questions about our universe.
The Webb Telescope, named after NASA's second administrator, will be about half the size of the 24,000-pound Hubble, but is armed with significantly more capabilities.
Its primary light-gathering mirror will be 20 feet in diameter, compared with Hubble's eight, and will detect visible light at one 100th the brightness of its predecessor and four 100ths the brightness of infrared light. The improved infrared capabilities will allow astronomers to examine light from the first emerging galaxies that formed from the rapid expansion and cooling of the universe just a few hundred million years after the \big bang.""
Dr. Sanjay Limaye, director of the UW-Madison Office of Space Science, said the infrared improvements on the Webb Telescope will give astronomers gain new insight.
""With Hubble, when they wanted to look at faint stars, the visible light could be blocked by dust,"" Limaye said. ""The new telescope will be able to penetrate through interstellar dust, just like looking clearly at objects through smoke.""
The Webb Telescope will also search for planet formations in disks around young stars, as well as study massive black holes in distant galaxies. According to NASA, it will last from five to 10 years and cost approximately $1.2 billion.
In an interview with The New York Times, Dr. Alan Dressler, astronomer with the Observatories of the Carnegie Institution in Pasadena, Calif., said the Hubble's successor has a tough act to follow.
""The Hubble Space Telescope raised the ante,"" Dressler said. ""The desire was to make a huge leap, to go for something bold that would really be a breakthrough. So the goal became to see the first light of stars and the emerging of galaxies.""
Designed in the 1970s and launched in 1990, Hubble orbits the earth at a distance of 375 miles, circling about once every 97 minutes. Every day the spacecraft sends between 10-15 gigabytes of information back to astronomers around the world. Hubble has observed more than 25,000 astronomical targets and traveled well over 1.5 million miles.
Dr. Jim Lattis, Director of UW Space Place, said perhaps Hubble's main contribution to science was the determination of the ""Hubble Constant"", a formula which estimates the rate at which the universe is expanding from a ""big bang"" some billions of years ago, providing a more accurate idea of the age of the universe.
""[HST] was able to provide astronomers with data that reconciled conflicting values,"" Lattis said. ""so that now we can say with some confidence that the ""Big Bang"" occurred about 14 billion years ago.""
Lattis said the Webb Telescope will allow astronomers to carry on their search to understand some of the largest questions scientists have been asking for years.
""We build space telescopes and other instruments because we want to know about the universe,"" Lattis said. How big is it? How old? How did it develop? How did it produce us? Did it produce any other life? How will it develop in the future? These are big questions, and only answerable by our best efforts.\
