Posted on: Tuesday, March 16, 2004
COMMENTARY
Advancing science and safety
By Sean O'Keefe
Administrator of the National Aeronautics and Space Administration
Not a day goes by that the men and women of NASA are not mindful of the lessons of the Columbia accident. As we prepare to return the space shuttles to flight, we are determined to do everything necessary to reduce risk.
Because we are committed to complying with the safety recommendations of the Columbia Accident Investigation Board, I decided two months ago to cancel the final mission to maintain and repair the Hubble space telescope. In making my decision, I had to balance the world-class science that the Hubble has produced, and will continue to produce, against the risks to the shuttle and its crew.
The safety considerations tipped the scales. I welcome the decision of the National Academy of Sciences, announced last week, to review my conclusion.
In its report, the Columbia Accident Investigation Board called for the development of on-orbit inspection, repair and contingency rescue requirements for every shuttle flight. Those requirements bear on any decision to proceed with shuttle operations — especially on requirements for a maintenance mission to the Hubble.
A mission to the Hubble would be the sole remaining shuttle flight not directed to the International Space Station. It would also require us to develop a unique set of procedures, technologies and tools in the few years before the Hubble's batteries and other critical systems give out.
We are making steady progress in our efforts to meet the safety requirements for the shuttle's return to flight next year. But it is unlikely that we will be able to develop in time the safety and return-to-flight elements for a mission to the Hubble before it stops working in about 2007.
Accordingly, it may not make sense to devote time and energy to a mission to the Hubble — only to find that the safety actions and procedures required by the board could not be followed. This would place NASA in the untenable position of having to decide whether to undertake the Hubble mission without the required safety elements in place.
This is precisely the type of "schedule pressure" that the board quite correctly cited as undermining the future safe operation of the shuttle.
What has been lost in all the discussion about the Hubble is some very good news about this remarkable scientific instrument. First, even without a servicing mission, we expect the Hubble will continue to be scientifically useful for two to three more years, exceeding its planned 15-year life span by more than a year.
In addition, NASA has asked for ideas on how to extend the Hubble's service even more. There may be ways to keep the Hubble operating even if some of its batteries and gyroscopes fail. The International Ultraviolet Explorer, for example, a spacecraft intended to last three to five years when it was launched in 1978, kept operating for nearly 18 years. It may also be possible to maintain the Hubble robotically.
With the focus of our talented Hubble team, I am confident we will keep this magnificent telescope working for several years to come. We are also encouraged by preliminary assessments of alternative options for the instruments that would have flown on a Hubble mission.
In addition, NASA is proceeding as planned with three astronomy projects (the Kepler space telescope, the Space Interferometry Mission and the James Webb space telescope) that will help us peer ever farther into space.
America's space program is at a crossroads. Prompted by the tragic loss of Columbia and its crew last year, we are making important changes in the way we operate our missions. But we are also looking forward to new challenges.
As we develop new capacities, we must always work to improve the safety of our missions and our spacecraft. We are resolved that the legacy of Columbia will be with us not just today, but through all our journeys.
