The Next Generation Space Telescope is being planned to take up where the Hubble mission ends, with the search for the first light that appeared after the universe's creation.
NASA plans one last upgrade to the Hubble Space Telescope to keep the observatory equipped for cutting-edge research until 2010. After that, NASA said it would decommission the telescope and possibly dispatch a shuttle crew to return Hubble to Earth as a museum piece. By then, NASA hopes its follow-on to the Hubble program already will be in orbit.
The new space telescope, which is known by the acronym NGST, is scheduled for launch in 2009 aboard an unmanned Atlas booster. There will be no astronaut service calls to NGST, which will be hurled beyond Earth's moon to conduct its five- to 10-year mission.
From an orbital perch more than 1 million miles away, NGST will be able to use its night-vision imagers to pick up the faintest glow from the universe's first stars and galaxies without interference from Earth's heat and light and without the planet itself blocking the view. At the same time, NGST will be well positioned for communications with ground-based science and operations teams on Earth.
NASA considers the time and expense of a new telescope a good investment.
"Hubble is based on 1970s and 1980s technology," said NASA's space sciences chief Ed Weiler. "You reach a point where there is only so much more you can do. Besides, we have an agreement with the scientific community to fund NGST, which we can do by eventually eliminating funding for Hubble."
With a diameter of 26.9-feet, the new telescope's light-collecting mirror will be more than three times the size of Hubble's relatively modest 7.9-foot primary mirror.
"We hope to see back to when the first light turned on," said NGST project manager Bernard Seery, with NASA's Goddard Space Flight Center in Greenbelt, Md.
NASA and its contractor teams borrowed from declassified spy satellite technology to design a lightweight mirror that could unfurl in space like flower petals. The telescope's cost is expected to be about $900 million.
Hubble, in contrast, cost $2 billion to build. With corrective optics, upgrades, repairs, maintenance and ground operations over the telescope's 20-year lifetime the bill blossoms to $10 billion.
Astronomer and astronaut John Grunsfeld, who has participated in two Hubble servicing missions, said the telescope already has proven its worth.
Historians will see Hubble as "the most productive scientific instrument in human history -- it's had that big an impact on people's lives," he said.
"Personally, I would much rather have Hubble in orbit doing science than in the Smithsonian for people to see," he added. "I think the incredible discoveries that Hubble makes -- not just once, every five years, but it seems like every few months something comes from Hubble that nobody expected and it's earthshaking -- I think people would rather have those discoveries than have Hubble in the Smithsonian.
"I think the best thing that we could do with Hubble is at least to keep it going so that it has a fair overlap with Next Generation Space Telescope," Grunsfeld said. "That allows us to do simultaneous observations and to make sure that the new telescope works well."