
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, July 22, 1990                   TAG: 9007220121
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-4   EDITION: METRO 
SOURCE: The Hartford Courant
DATELINE:                                 LENGTH: Medium

HUBBLE DEFECTIVE AT OUTSET

The flaw in the Hubble Space Telescope almost certainly occurred in a part of the manufacturing process so basic that everyone assumed it would be done right, several key scientists said in interviews last week.

The scientists, some of whom worked directly on the $1.5 billion telescope project, suggest that the measuring instruments made and used by a Connecticut company to create the Hubble's two mirrors were either faulty or improperly used. The instruments are optical devices called null correctors and are used to guide the grinding and polishing of telescope mirrors. The same instruments were then used to test the mirrors after they were completed.

Because one or both mirrors were shaped incorrectly, the Hubble cannot properly focus the light from distant stars as it orbits 380 miles above the Earth. About half of its eagerly anticipated astronomical research must be delayed until a solution is found, and the telescope's partial failure has led to renewed questions about the ability of U.S. technology and the space agency to take on big projects.

The complex technical requirements of making the telescope were only one aspect of the challenge faced by NASA and Perkin-Elmer Corp., which manufactured the mirrors in Danbury, Conn. Perkin-Elmer last year sold the division to Hughes Aircraft Co., which renamed it Hughes Danbury Optical Systems Inc.

Critics say that the telescope was built under the pressures caused by management troubles, missed deadlines and cost overruns. Because of those problems and overconfidence in Perkin-Elmer's technical abilities, the critics say, not enough tests were performed on the telescope before it was launched into space April 24.

Although investigators have performed no tests yet on the null correctors, the scientists said that other possibilities appear to be remote. They said they have verified the mathematical "prescription" for the telescope's mirrors and have determined that its focusing equipment is functioning properly.

"The question is, was the null corrector manufactured as it was supposed to be so that the mirror was built to the correct shape?" said Abe Offner, a retired scientist who designed the null system in the 1970s for Perkin-Elmer Corp.

Offner said he was almost certain that the null corrector was flawed.

Offner is among several scientists scheduled to meet Wednesday and Thursday in Danbury with a special six-member NASA review team that is investigating the cause of the Hubble's troubles.

Awaiting the investigation team are boxes of documents, enough to fill a school bus, and several rooms of Hubble equipment, some untouched since the mirrors left the factory nearly six years ago. Since the disclosure of the telescope's problem on June 27, the company has been collecting and categorizing the documents.

by CNB