Endeavour's difficulties jeopardize UA research

By Zach Thomas

Arizona Daily Wildcat

University of Arizona experiments aboard the currently orbiting space shuttle Endeavour (STS-69) were to usher in new knowledge of both the Earth's upper atmosphere and Jupiter's moon Io.

However, half of Endeavour's 11-day mission is now in jeopardy as technical problems are preventing the full-function of UVSTAR (Ultraviolet Spectrograph Telescope for Astronomical Research), one of two UA projects aboard the shuttle.

Designed for long-range spectral observations in space, UVSTAR is being hampered by the loss of motion in certain directions, severely limiting the range of its observations.

"We are able to move on one axis," said A. Lyle Broadfoot from the Payload Operations Command Center in Maryland. Broadfoot is a UVSTAR principal investigator and UA Lunar and Planetary Laboratory researcher.

"However, the other axis is frozen up," he said. "We'll still get some data, but we will not be able to hold a target for long."

The vacuum pumps, designed to maintain a "hard vacuum" inside the instrument, also are not functioning. Sunday, the UA team in Maryland successfully pumped the mechanism naturally by exposing it to the vacuum of space. UVSTAR is now activated, and the team is receiving limited data from the instrument.

A joint operation between the LPL and Italy's University of Trieste, UVSTAR was initially designed in Italy and constructed at the LPL in Tucson for long-range UV observations. Its planned examinations of the UV emissions of Jupiter's moon, Io, as well as other galactic and extragalactic objects are now in jeopardy.

"It is unfortunate," Broadfoot said. "It is a new experiment, and someplace there is a problem."

Arizona Airglow (GLO-3), the second UA experiment aboard the shuttle, is functioning as expected. Able to observe a much broader range of light at a lesser magnification than UVSTAR, the GLO-3 experiment will focus on the shuttle's interaction with the atmosphere during routine spacecraft operations, as well as studying the Earth's upper atmosphere.

"Up until today, we have had very limited data of the atmosphere at a very high altitude and theories have built upon themselves," said Mark Jacobs, a graduate research assistant associated with the project at LPL.

"We hope to validate or change current models of upper atmosphere," said Jesus Ramirez, an LPL draftsman.

Now on its third trip to space, the GLO project was developed as a joint project between the UA's LPL and the U.S. Air Force. The instrument contains a set of imaging spectrographs able to simultaneously observe wavelengths from infrared to ultraviolet, an operation never before possible. The mechanism also is automated to the point that observations can be made while the astronauts are asleep.

The UA's LPL maintains a continuously updated World Wide Web page for the projects at http://vega.lpl.arizona.edu/~ramirez/sts-69.html. The page provides technical schematics, project overviews and up-to-date experiment status as well as links to other projects aboard STS-69.

Flandrau Science Center and Planetarium is also providing coverage of the shuttle mission during business hours. For more information about hours and coverage interruptions, call 621-STAR or the Flandrau Administration Offices at 621-4515.

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