Does the Hubble Telescope Matter?

by George F. McClure

The Hubble space telescope has vastly improved the understanding of astronomy since its launch in 1990 by the crew of the Space Shuttle Discovery. Since then, it has been serviced four times by astronauts who conducted maintenance and installed upgraded components critical to its continued operation. However, in the aftermath of the loss of the Space Shuttle Columbia in 2003, NASA has declined to schedule any further use of astronauts on the Hubble, claiming it is too risky for the astronauts. There is no current budget for another mission to upgrade the Hubble. Already, the unmanned Russian supply ship Progress is conducting resupply missions to the International Space Station, rather than shuttle missions. If no action is taken, the Hubble will likely fail catastrophically by 2008.

Without Hubble, astronomers’ most valuable window on the universe could be closed for five years or more. NASA’s plan for now is to remove Hubble from orbit so that its atmospheric reentry is controlled and it crashes safely in the ocean.

Is NASA making the right decision?

NASA is working on a successor space telescope, the James Webb (named for a past NASA administrator), originally scheduled to be ready in 2007, but now planned for 2011. The James Webb will see only infrared wavelengths; the Hubble covers the visible light spectrum and ultraviolet bands with precision. Other instruments have provided indicators that led to more detailed discoveries by the Hubble. For example, the orbiting Compton Gamma Ray Observatory found thousands of gamma-ray bursts in the 1990, but it took Hubble to discover what was causing them. The Spitzer infrared observatory, launched in 2003, is expected to become inoperative after 2008.

The Cosmic Origins Spectrograph and the Wide Field Camera 3 are two new instruments built and awaiting installation in the Hubble. They would further expand the telescope's existing capability.

What's wrong with the Hubble?

Gyroscope and battery failure are the most serious threats to the Hubble's survival. Launched with six functioning gyroscopes, the space telescope is down to three, and there are plans for continuing its mission with only two. Imminent battery failure is a more serious problem, spelling certain doom for the telescope unless its power source is replaced.

Limited options for Hubble

NASA had estimated the cost of a Hubble rescue mission, utilizing a space shuttle and crew of astronauts, at $1.7 billion to $2.4 billion. But the Government Accountability Office, after reviewing the estimate, concluded that the estimates were not fully developed and were based on insufficient supporting documentation [www.gao.gov/highlights/d0534high.pdf and www.spacetoday.net/Summary/2708].

NASA’s Administrator, Sean O’Keefe, had stated earlier that a robotic mission to repair the Hubble could be acceptable, since it would not risk astronaut’s lives. The centerpiece for such a mission would be use of a Canadian-built robot nicknamed “Dextre.”

But a report by the independent National Research Council (NRC), a division of the National Academies of Science, doubted that such an ambitious and complex rescue project, involving a robot working from an unmanned spacecraft, could be completed in the time required. The report said that such a rescue posed technical challenges so complex that they will be "unlikely" to be resolved in time to prevent Hubble from shutting down; and that a realistic schedule would include roughly 65 months development time, with the work completed by 2010. The panel concluded that a manned mission should be used instead, and that it could do the job without posing unacceptable risks to shuttle astronauts. NRC's report reopened debate over O'Keefe's January decision to cancel a scheduled shuttle servicing mission because of the risks to astronauts.

The President’s Fiscal Year 2006 budget does not include funding for NASA to develop the robotic capability to save the Hubble. The funding is instead being shifted to manned space exploration.

IEEE-USA urges full study of the alternatives to save the Hubble

NASA should "strive to develop procedures, technology and equipment that would allow the safe servicing of the Hubble Space Telescope, including the possible use of tele-operated robots," according to an IEEE-USA policy position statement adopted last year [read full IEEE-USA position statement].

IEEE-USA's position states that "NASA should continue planning and preparing for the [space shuttle] SM-4 [servicing] mission, while expert panels and the National Academy of Science develop their reports and the [servicing] issue is thoroughly reviewed." IEEE-USA stressed that it "supports exploring all possible avenues to prolong the useful life of the telescope for the benefit of science and humanity."

In an earlier letter to Congress on the Hubble Space Telescope, IEEE-USA 2004 President John Steadman strongly supported NASA's decision and the recommendations in the National Academies report to "commit to a servicing mission to the Hubble that accomplishes the objectives of the originally planned SM-4 mission, including both the replacement of the present instruments with the two instruments already developed for flight...and the engineering objectives, such as gyroscope and battery replacements."

In his letter, Dr. Steadman noted that the Hubble telescope has provided fundamental new results in planetary science; led to the discovery of the most distant object in the solar system; provided more accurate estimates of the age of the universe; offered better measurements of the universe's rate of expansion; provided the deepest portrait of the visible universe; led to the discovery of new stars and dynamic phenomena in space; and offered new views of comets and black holes.

The House Science Committee held hearings on the Hubble in February. IEEE-USA submitted a statement for that hearing, urging that all options be explored to save the space telescope [see related IEEE-USA news release].

IEEE-USA not alone in supporting Hubble

Senator Barbara Mikulski (D-Md.) became a champion for saving the Hubble. Much of the work to save the Hubble would be done at Goddard Spaceflight Center, in Greenbelt, Md. [www.thesentinel.com]. Other supporters formed a Web site [www.savethehubble.org], where more than 40,000 supporters have signed a petition and where concerned parties can make financial donations to the cause.

George McClure is chair IEEE-USA's Communications Committee, a member of the IEEE-USA Career & Workforce Policy Committee, and technology policy editor for IEEE-USA Today’s Engineer. Comments may be submitted to todaysengineer@ieee.org. Opinions expressed are the author's.