The Hubble Space Telescope is considered one of astronomy's most important instruments. As Hubble marks its 15th anniversary in orbit, VOA's Jim Bertel reports its future hangs in the balance.
Fifteen years ago, the U.S. space agency, NASA, launched a new era in astronomy. After overcoming a few early problems, the Hubble Space Telescope has changed the way man views the universe.
David Leckrone says, "It's very hard to pick up an astronomy textbook today that isn't just permeated by both Hubble imagery and the discoveries that have come from Hubble."
Mr. Leckrone is the telescope's chief scientist, and has been with the program since its beginning. He says many of the greatest discoveries made by the telescope were complete surprises.
"It answers questions we didn't even know how to ask prior to Hubble being launched," Mr. Leckrone says.
Over the years Hubble's steady flow of scientific breakthroughs and spectacular images were made possible by regular visits by shuttle astronauts, to make repairs and upgrade its instruments. Without another servicing mission, the telescope's mechanical components are expected to wear out in 2007.
After the 2003 loss of the space shuttle Columbia, however, a final visit to extend the life of Hubble was cancelled. Astronomers, the public and Congress argued vehemently that Hubble was worth saving. At the request of Congress, the National Research Council of the National Academies conducted an independent review of two servicing options: reinstating the shuttle flight or developing a robotic servicing mission.
"The committee concluded -- with regret -- that the robotic servicing option was probably not feasible within the remaining, limited life span of Hubble prior to servicing," says Sandra Graham, who is with the National Academies.
Ms. Graham was the study director. Her committee, consisting of engineers, astronomers and many former NASA officials, concluded a shuttle mission was the best option. Among their considerations was the danger associated with flying astronauts to Hubble. The panel concluded the primary risk of catastrophic damage to the space shuttle occurs during the launch and reentry.
"So the amount of risk, or the difference in risk between going to the Hubble space telescope and the International Space Station, even given the possibilities that the International Space Station provides for safe haven, the difference in the risk is still very small," she says.
Supporters of a Hubble servicing mission were given renewed hope with the arrival of new NASA Administrator Michael Griffin who promises to reconsider his predecessor's decision to cancel the manned servicing mission once the shuttles resume flying.
"Immediately after the first is launched, we are going to undertake an internal review to weigh the pros and cons of reinstituting SM4 Hubble - Shuttle servicing mission 4," said Administrator Griffin.
Mr. Griffin has ruled out a robotic servicing mission as being unfeasible. Even if a decision is made not to send a shuttle to Hubble, Sandra Graham says there will be at least one more mission, a robotic flight to safely de-orbit Hubble into a pre-selected patch of ocean.
"It will land somewhere and it will land hard. And if we want to guarantee that it lands in the ocean rather than on Paris or New York City, a de-orbit mission is required," says Sandra Graham.
No matter the fate of Hubble, Chief Scientist David Leckrone believes the telescope's place in history is assured, and a century from now people will still be talking about what Hubble achieved.