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Publications and Public Affairs
ALUMNI KOHL AND GLENN REUNITED BY SHUTTLE FLIGHT
"We had a flawless execution," said NASA project leader Craig Tooley at a televised press conference from the Johnson Space Center in Houston immediately following recovery of the Spartan 201 satellite by the Discovery astronauts late on the afternoon of November 3.
The solar physics satellite, carrying an ultraviolet coronagraph spectrometer (UVCS) built by SAO, had been deployed two days earlier by the same astronauts for a 45-hour experiment to observe the Sun's hot outer atmosphere, or corona. Although the final results won't be known until the experiment is opened and its video tapes inspected on the ground, the quick-look data analysis has convinced John Kohl that he and his team of colleagues and collaborators at SAO have moved closer to solving one of solar physics' fundamental problems: What forces accelerate the solar wind?
For Kohl, the quest to answer this question goes back to 1962, when NASA's Mariner II spacecraft first observed a powerful stream of supercharged particles flowing out of the Sun at velocities many times higher than had been predicted by theory.
Since that year, when Kohl was an undergraduate at Muskingum College in New Concord, Ohio, much has been learned about the nature of the wind. No small part of that new understanding has come from Kohl's experiments aboard three previous Spartan flights, as well as a larger version of UVCS now flying aboard the international Solar and Heliospheric Observatory (SOHO). Indeed, thanks to the timely recovery and repair of SOHO only a month earlier, simultaneous observations of the same regions of the Sun were made with the two nearly identical SAO instruments aboard the two spacecraft, a scientific first that could have profound implications for understanding the origin and nature of the solar wind.
Of course, 1962 was also the year another former Muskingum College student became the first American in Earth orbit. Inspired by the exploits of his fellow alumnus, the young John Kohl went on to pursue a career in science, one which ultimately reunited Astronomer Kohl with Astronaut Glenn on Shuttle flight STS-95.
As Kohl related in the post-mission press conference: "Both the Mariner discovery and John Glenn's flight had a great influence on my life and career." Indeed, as he told the media, when Mrs. Glenn visited the Spartan Operations Center on November 2, Kohl could describe for her how his research had "common roots in both the space achievements of 1962--and in Muskingum College."
"To paraphrase Sammy Sosa," said Kohl. "NASA has been very good to me."
[In addition to John Kohl, the SAO UVCS/Spartan/SOHO team, which has had a banner year of scientific successes in space, includes: Lorraine Allen, Nigel Atkins, Brenda Bernard, Angela Ciaravella, Mario Cosmo, Steven Cranmer, Peter Daigneau, Edward Dennis, Danuta Dobrzycka, Ruth Esser, Silvano Fineschi, Elaine Fortin, Richard Frazin, Larry Gardner, Shadia Habbal, Chris Halas, Roger Hauck, Margarita Karovska-Neily, Yuan-Kuen Ko, Jing Li, Xing Li, Joseph Michels, Mari Paz Miralles, George Nystrom, Alexander Panasyuk, John Raymond, Frank Rivera, Peter Smith, Leonard Strachan, Raid Suleiman, and Chi-Rai Wu.]
With SAO's Wally Tucker (at podium) serving as moderator, the Shuttle crew that will take AXAF into space answered questions from SAO staff and their families. As seen here (from right), the crew includes Eileen Collins, mission commander; Jeffrey Ashby (Cmdr., USN), pilot; Steven Hawley, Ph.D., mission specialist; Catherine Cady Coleman, Ph.D. (Major, USAF), mission specialist; and Michel Tognini (col., French Air Force), mission specialist. (Photo by Mary Juliano)
NASA's Advanced X-ray Astrophysics Facility (AXAF) has been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel laureate, Subrahmanyan Chandrasekhar. The telescope is scheduled to be launched no earlier than April 8, 1999, aboard the Space Shuttle Columbia mission STS-93, commanded by astronaut Eileen Collins.
Chandrasekhar, known to the world as Chandra, which means "moon" or "luminous" in Sanskrit, was a popular entry in a recent NASA contest to name the spacecraft. The contest drew more than six thousand entries from fifty states and sixty-one countries. The co-winners were a tenth grade student in Laclede, Idaho, and a high school teacher in Camarillo, CA.
The Chandra X-ray Observatory Center (CXC), operated by the Smithsonian Astrophysical Observatory, will control science and flight operations of the Chandra X-ray Observatory for NASA from Cambridge, Mass.
"Chandra is a highly appropriate name," said Harvey Tananbaum, Director of the CXC. "Throughout his life Chandra worked tirelessly and with great precision to further our understanding of the universe. These same qualities characterize the many individuals who have devoted much of their careers to building this premier x-ray observatory."
"Chandra probably thought longer and deeper about our universe than anyone since Einstein," said Martin Rees, Great Britain's Astronomer Royal.
"Chandrasekhar made fundamental contributions to the theory of black holes and other phenomena that the Chandra X-ray Observatory will study. His life and work exemplify the excellence that we can hope to achieve with this great observatory," said NASA Administrator Dan Goldin.
Widely regarded as one of the foremost astrophysicists of the 20th century, Chandrasekhar won the Nobel Prize in 1983 for his theoretical studies of physical processes important to the structure and evolution of stars. He and his wife immigrated from India to the U.S. in 1935. Chandrasekhar served on the faculty of the University of Chicago until his death in 1995.
The Chandra X-ray Observatory will help astronomers worldwide better understand the structure and evolution of the universe by studying powerful sources of X rays such as exploding stars, matter falling into black holes and other exotic celestial objects. X-radiation is an invisible form of light produced by multimillion degree gas. Chandra will provide x-ray images that are fifty times more detailed than previous missions. At more than 45 feet in length and weighing more than five tons, it will be one of the largest objects ever placed in Earth orbit by the Space Shuttle.
Tyrel Johnson, a student at Priest River Lamanna High School in Priest River, Idaho, and Jatila van der Veen, a physics and astronomy teacher at Adolfo Camarillo High School in Camarillo, California, who submitted the winning name and essays, will receive a trip to the Kennedy Space Center in Florida to view the launch of the Chandra X-ray Observatory, a prize donated by TRW.
Members of the contest's selection committee were Timothy Hannemann, executive vice president and general manager, TRW Space & Electronics Group; the late CNN correspondent John Holliman; former Secretary of the Air Force Sheila Widnall, professor of aeronautics at MIT; Charles Petit, senior writer for U.S. News & World Report; Sidney Wolff, Director, National Optical Astronomy Observatories; Martin Weisskopf, Advanced X-ray Astrophysics Facility project scientist, Marshall Space Flight Center, Huntsville, AL.; and Harvey Tananbaum, director of the Advanced X-ray Astrophysics Facility Science Center, Smithsonian Astrophysical Observatory, Cambridge, MA.
The Chandra X-ray Observatory program is managed by the Marshall Center for the Office of Space Science, NASA Headquarters, Washington, DC. TRW Space and Electronics Group, Redondo Beach, CA, is NASA's prime contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations of the observatory for NASA from Cambridge, MA.
The process that will convert the Multiple Mirror Telescope (MMT) from an unusual instrument with six relatively small mirrors to one sporting a single 6.5-meter-diameter mirror continues apace in Arizona.
In July, staff from The University of Arizona's Steward Observatory, the Smithsonian Institution's Fred Lawrence Whipple Observatory (FLWO), and the jointly operated Multiple Mirror Telescope Observatory (MMTO) moved the new 6.5-meter primary from the UofA Mirror Lab in Tucson to the FLWO basecamp in Amado. In a separate operation the next month, the "cell" that will support the 9500-kilogram borosilicate mirror in the telescope assembly was successfully transported up the winding dirt road to the summit of Mt. Hopkins and installed in the building. Then, in mid-November, the huge vacuum dome to be used for re-aluminizing the mirror was successfully inserted into the telescope assembly and placed over the "dummy" mirror in a crucial test. (Once installed on the MMT the giant mirror will never leave the mountain again, so its reflective surface will need to be periodically recoated in place.)
For example, the MMT has been specifically redesigned to accommodate spectroscopy with multiple fibers. With a field of view more than 400 times as large as that viewed by the original telescope, the new MMT will be particularly well-suited to large-scale surveys of faint objects in deep space. And, Hectospec, an instrument being designed and built by SAO scientists and engineers, will be one of the most powerful tools available to study the evolution of large-scale structures in the universe.
"As a multi-object spectrograph, Hectospec will enable us to record the redshifts, a measure of recession velocity that can be translated into distance, of several thousand galaxies in one night," says Dan Fabricant, project head.
In essence, the device works by simultaneously collecting light from up to 300 galaxies during a single exposure, using optical fibers that are precisely placed at the telescope's focal plane by high-speed robots. The "robots" are not the humanoid variety, however. Rather they are two large arm-like machines, each with a palm-sized gripper capable of picking up and placing a magnetic-tipped optical fiber at those exact spots on the concave surface where light from the distant galaxies is to be focused.
The fibers serve as conduits for transmitting the light to the spectrograph. "In just 300 seconds, the robots can reposition 300 fibers to match a new set of galaxies in the sky," says Edward Hertz, project engineer for Hectospec.