[FPSPACE] NASA told to use Shuttle for Hubble repair
zirconic1 at earthlink.net
Wed Dec 8 22:47:52 EST 2004
Use Shuttle To Fix Hubble, NASA Is Told
Risks to Astronauts Acceptable, Panel Says
By Guy Gugliotta
Washington Post Staff Writer
Thursday, December 9, 2004; Page A01
A panel of experts handed NASA's leadership a sharp reproof yesterday, concluding that the space shuttle should be used to service the Hubble Space Telescope and can do the job without posing unacceptable risks to the astronauts.
The experts also said NASA's plan to service the telescope with a robot working from an unmanned spacecraft was unrealistic, posing technical challenges too complex to be resolved by 2007 -- when Hubble's machinery could start to wear out.
The long-awaited report, prepared for NASA by the National Research Council, a division of the independent National Academies of Science, directly challenged NASA Administrator Sean O'Keefe's decision to cancel a planned shuttle servicing mission because of unacceptable risks to the astronauts and to mount the robotic mission instead. O'Keefe asked for the academy's review after a storm of criticism over his decision.
The report was certain to reignite the debate. Sen. Barbara A. Mikulski (D-Md.), whose state is home to the facility that maintains the telescope and oversees its scientific agenda, issued a statement commending the panel for "this outstanding report" and promised to hold hearings in February on its findings.
Also sure to resurface are arguments over the costs of keeping the Hubble going. O'Keefe has put the price of a robotic mission at between $1 billion and $1.6 billion, and NASA suggested in a letter cited in the council report that a shuttle mission would cost between $1.7 billion and $2.4 billion. The report, however, predicted "substantially lower actual costs" for shuttle servicing with "careful planning."
"We find . . . it highly unlikely that the design life of the Hubble will be extended through robotic servicing," summed up panel chairman Louis J. Lanzerotti, a research physicist at the New Jersey Institute of Technology. "A shuttle servicing mission . . . is highly likely to succeed."
O'Keefe's January decision to cancel further servicing missions essentially condemned the Hubble to death sometime around 2008, provoking national outrage. A few months later, the agency announced it would mount a robotic mission to fly by the end of 2007 to replace the Hubble's gyroscopes and batteries, add new two instruments and possibly replace a key piece of machinery.
NASA officials did not respond directly to the council report yesterday, but the agency issued a statement saying it "appreciates the thoughtful assessment, and we are grateful the Academy was able to provide this study in an expeditious manner. The thorough nature of the report is such that NASA will require some time to study the recommendations."
The Hubble telescope, launched in 1990 into an orbit 360 miles above Earth, has been serviced four times by shuttle astronauts, who have replaced or enhanced almost every piece of equipment on board, adding new capabilities on each trip.
"When I started, I wasn't necessarily an advocate for saving the Hubble," said retired aerospace executive Roger E. Tetrault, a member of both the council panel and the Columbia Accident Investigation Board, whose report on the disintegration of the space shuttle Columbia last year prompted O'Keefe to cancel the shuttle servicing mission.
But Tetrault became a convert, as did the rest of the panel, saying that Hubble is "the most powerful optical astronomical facility in history," and, if given a fresh lease on life, would have the same potential for new discoveries that it had when it was launched.
"We had to save Hubble," Tetrault said at a news conference called by the academy to announce the panel's findings. "So how do you do it?"
Engineers at the Goddard Space Flight Center in Greenbelt, charged with developing the robotic repair mission, have acknowledged that the mission is one of the most complex space endeavors ever attempted but have grown increasingly optimistic about their ability to accomplish it, largely because of the skills of a Canadian-built robot nicknamed Dextre.
The council, however, reviewed all the tasks associated with the mission and concluded that "the likelihood of successful development of the [Hubble] robotic servicing mission [by December 2007] is remote."
Instead, the report said, the council agreed with a private Aerospace Corp. analysis prepared for NASA that suggested "that a successful mission of this level of complexity would require a nominal development time of the order of 65 months" -- no sooner than 2010.
By that time, Lanzerotti said at the news conference, gyroscope failures will likely have forced scientists to discontinue observations for more than two years, and the Hubble's batteries would be dangerously close to wearing out, causing a fatal breakdown within hours. Should a robotic mission arrive in 2010, "one might not find a usable vehicle," Lanzerotti said.
The council also sharply disagreed with O'Keefe's assessment that the space shuttle could not fly to the Hubble and still comply with the risk reduction recommendations of the Columbia accident investigators -- that the astronauts be able to perform onboard damage inspection and repair.
NASA decided that the shuttle should travel only to the international space station, whose crew could assist with damage inspections and tools, and provide a "safe haven" for the shuttle astronauts if they had to abandon a wounded spacecraft.
The council, however, said that by the time a mission to Hubble is mounted in 2006 or 2007, the shuttle would have the ability to do its own inspection and repair with the aid of sensors and spacewalks, and, if necessary, could "power down" in a cocoon-like safe-haven mode for as long as 30 days while awaiting a rescue mission.
This, said panel member Richard H. Truly, a retired Navy vice admiral, astronaut and NASA administrator, would be a safe, "viable approach."
The panel agreed that NASA needs to replenish and refit the space station with the first few trips after the shuttle returns to flight -- now planned for next May. But by late 2006 or 2007, a Hubble mission would "balance quite nicely" with the Hubble's needs, Truly said.
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