University alumnus will travel to Hubble for repair mission

Four University astronomers who use the Hubble Space Telescope in their research are depending on astronaut-alumnus John Grunsfeld (S.M., ’84, Ph.D., ’88) to help put it back in working order during the space shuttle Discovery mission scheduled for launch at 12:10 a.m. CST Thursday, Dec. 9.

The Hubble Space Telescope’s observations were suspended Saturday, Nov. 13, when one of its three operational gyroscopes failed.

The telescope can still be controlled from the ground, but with only two working gyros, it cannot be aimed with the precision necessary to make scientific observations.

A veteran of two shuttle flights, the 41-year-old Grunsfeld will be among four spacewalkers who will replace the telescope’s six gyros and other key components during the servicing mission.

The telescope is named for Edwin Hubble (S.B., ’10, Ph.D., ’17), another Chicago alumnus.

Hubble’s discoveries form the cornerstone of the big-bang theory of the universe’s origin and opened the field of cosmology. In addition to receiving his bachelor’s and doctoral degrees from Chicago, Hubble conducted his student research at the University’s Yerkes Observatory in Williams Bay, Wis.

“After all the birthing troubles, the Hubble Space Telescope has been just a marvelous instrument,” said Lewis Hobbs, Professor in Astronomy & Astrophysics. Hobbs has conducted research with the telescope since its 1990 launch.

“I think it’s fair to say that the Hubble Space Telescope has exceeded expectations in the long run. It’s been a very, very productive instrument.”Hobbs, fellow Chicago astronomers Daniel Welty, Senior Research Associate in Astronomy & Astrophysics, and Donald York, the Horace B. Horton Professor in Astronomy & Astrophysics, and Donald Morton of the Herzberg Institute for Astrophysics in Ottawa, Canada, continue the study they began in the 1960s with ground-based telescopes.

For many years, this team collaborated with Princeton University’s Lyman Spitzer on a study of interstellar gas and dust clouds. Spitzer, who conceptualized the Hubble Space Telescope and was instrumental in its development, died in 1997.

If the repair mission goes well, next year the team will study the elemental abundance and physical conditions characterizing the interstellar gas and dust in the Small Magellanic Cloud, a small companion galaxy to the Milky Way in which heavy elements such as carbon, oxygen, silicon and iron are less abundant than in the Milky Way.

The properties determined for the interstellar matter in the Milky Way and Small Magellanic Cloud will be used to help interpret similar data obtained for gas clouds in the far-distant universe, where even lower amounts of heavy elements are often found.

In this way, Welty said, “we may be able to trace the buildup of heavy elements over much of the history of the universe––as they’re formed in stars and thrown out into the interstellar medium.”

With French astronomers, Hobbs continues a long-term Hubble study of the star Beta Pictoris. Astronomers suspect that one or more planets orbit the star, which is shrouded by a rich disk of gas and dust, though no one has been able to prove it.

“Beta Pictoris is much younger than the sun,” Hobbs said. “The hope is that by finding planets around enough other stars with a wide range of ages, we might get a glimpse of how planetary systems develop.”

In a separate study, Douglas Duncan, Associate Professor in Astronomy & Astrophysics, has trained the Hubble telescope on the oldest stars in the galaxy to trace the origin of certain light chemical elements. These elements, forged from the big bang, cosmic-ray collisions and exploding stars, ultimately became the stuff our bodies are made of, Duncan said.

For his next project, Duncan plans to use the Hubble Space Telescope to study a double-star system consisting of a huge, relatively cool star called a red giant and another star similar to the sun. He is especially interested in analyzing the sun-like star’s energy output. “It might very well represent a snapshot of what was going on here in the very early days of the solar system,” he said.

Editor’s note: The photo of astronaut John Grunsfeld and the background (Deep Field South) image documented by the Hubble Space Telescope were reproduced courtesy of NASA.