One small step for Jeff Hoffman, one large step for NASA.

After more than 150 parachute jumps, a hike up New Hampshire's Mt. Washington on skis, three previous space flights and other experiences in free-fall, Dr. Jeffrey A. Hoffman, NASA astronaut and Harvard astrophysics Ph.D. (1971), was ready last week when he stepped into space to repair one of the world's most expensive telescopes.

The New York native was one of four mission specialists aboard Space Shuttle Endeavor's recent Hubble telescope rescue mission, which included a NASA record five "extra-vehicular activities," or spacewalks.

Hoffman's task was to participate in spacewalks to conduct servicing and repair activities on the Hubble. The telescope was launched in 1990 with a misshapen mirror, due to a manufacturing error, which prevented it from discerning the more remote objects in the cosmos.

Hoffman and four other crewmates embarked upon several spacewalks last week and successfully installed a set of corrective mirrors and a new camera with corrective optics, replaced two rate-sensing gyroscopes and two magnetic sensing systems used in orienting the telescope and carried out a host of other necessary repairs, according to a NASA spokesperson.

According to Giovanni G. Fazio, lecturer in astronomy and one of Hoffman's mentors while he was at Harvard, Hoffman exuded confidence prior to the mission.

"A lot of us were very worried whether this repair could come off," says Fazio. "But Jeff was always very positive about it."

Hoffman graduated summa cum laude from Amherst College in 1966, received his doctorate in astrophysics from Harvard in 1971 and obtained a masters degree in materials science from Rice University in 1988. His doctoral work at Harvard focused on the design, construction, testing and flight of a balloon-borne, low-energy, gamma ray telescope.

But according to Hoffman's fellow graduate students, the future astronaut was never without some idea for an adventure in travel.

"What was anybody doing in the late 60s?" asks Professor of Astronomy Jonathan E. Grindlay, a Ph.D. candidate with Hoffman. "We did lots of crazy things, like heading for the mountains in New Hampshire and skiing in Colorado."

And despite his adventurous nature, says Fazio, Hoffman's friends and colleagues expected him to keep a bit closer to terra firma.

"We never expected him to become an astronaut," Fazio says. "He never discussed it."

Grindlay, however, disagrees. "In our grad student days, at the time of the Apollo moon landing, Jeff was pretty excited about [the idea of becoming an astronaut]," he says. "I don't think he thought it was a realistic opportunity at that time, but we were both speculating about how exciting it would be to do astronomy from space."

And Walter H. G. Lewin, professor of physics at MIT and a personal friend of Hoffman's says that Hoffman's quest for a journey into space was not an easy one.

According to Lewin, who was invited by Harvard to sit on Hoffman's Ph.D. committee, Hoffman decided to apply for the NASA astronaut program even though his chance for admission was about 12 in several thousand.