Grunsfeld’s last trip to repair the hubble space telescope

To say that he was excited would be an understatement. As an astronaut, Dr. Grunsfeld had twice journeyed to space to make repairs on humanity’s most vaunted eye on the cosmos, experiences he had described to a high-level panel pondering Hubble’s fate only a few months before as the most meaningful in his life. He was looking forward to leading the third and final servicing mission, which had been delayed by the loss of the shuttle Columbia and its crew the year before.

Thinking that the mission was now being scheduled, Dr. Grunsfeld raced to Washington, only to learn that Sean O’Keefe, NASA’s administrator, had canceled it on the ground that it was too risky. Wearing his other hat as NASA’s chief scientist, Dr. Grunsfeld now had the job of telling the world that the space agency was basically abandoning its greatest scientific instrument at the same time that it was laying plans for the even riskier and more expensive effort to return humans to the Moon.

He said he felt as if he had been hit by a two-by-four.

“Being an astronaut, there are not a lot of things that have really shocked me in my life,” Dr. Grunsfeld said in a recent interview. But, he added, “I don’t think anybody could ever prepare themselves for, you know, trying to bury something that they have said, âHey, this is worth risking my life for.’ ”

He went home that January night and wondered whether he should resign.

On May 12, he and six other astronauts commanded by Scott Altman are scheduled to ride to the telescope’s rescue one last time aboard the shuttle Atlantis. This will be the fifth and last time astronauts visit Hubble. When the telescope’s batteries and gyros finally run out of juice sometime in the middle of the next decade, NASA plans to send a rocket and drop it into the ocean.

If all goes well in what Dr. Grunsfeld described as “brain surgery” in space, Hubble will be left at the apex of its scientific capability. As chief Hubble repairman for the past 18 years, he has been intertwined with the Hubble telescope physically, as well as intellectually and emotionally. “He might be the only person on Earth who has observed with Hubble and touched Hubble,” said Bruce Margon, an astronomer at the University of California, Santa Cruz, and former deputy director of the Space Telescope Science Institute .