Chandra X-ray Observatory

Monday, March 1, 1999

Dave Drachlis
Media Relations Office
NASA Marshall Space Flight Center
(256) 544-6538

George Diller
Kennedy Space Center Media Relations
(407) 867-2468
george.diller-l@ksc.nasa.gov

In the Vertical Processing Facility at NASA's Kennedy Space Center, Fla., work continues on schedule toward the launch of the Chandra X-ray Observatory aboard Space Shuttle Columbia on July 9 on mission STS-93. The component rework of the Command and Telemetry Unit is being completed this week. The unit will arrive from the vendor Tuesday, March 2, and be re-installed into Chandra on Wednesday, March 3. The Interface Unit was removed from Chandra on Feb. 14 for rework and will be returned to Kennedy and re-installed on March 7 or 8. The Command and Telemetry Unit and Interface Unit then will undergo five days of testing.

A full state-of-health test for the telescope is scheduled to occur March 18. The attitude control thrusters will be helium flow-tested the following day.

Planning is under way for the arrival of the solar arrays. They are being transported by C-17 aircraft to the Shuttle Landing Facility with arrival currently scheduled for March 9. Operations to mate the arrays to Chandra are scheduled for the week of March 23 and they will be fully deployed for testing on March 27.

On March 31, Chandra will be hoisted from its test stand onto a fueling stand. Loading of fuel into the spacecraft is currently planned to begin on April 5 and will take 10 days to complete. These bi-propellant hydrazine and nitrogen tetroxide fuels will be used by the telescope to achieve its final orbit. Hydrazine also will be used by one of the telescope's subsystems associated with pointing of the telescope.

Finally, the spacecraft's batteries will be installed on April 17. Chandra then will be ready for the arrival at the Vertical Processing Facility of the Inertial Upper Stage booster on April 19.

Chandra arrived at Kennedy's Shuttle Landing Facility aboard an Air Force C-5 transport aircraft on Feb. 4. It was offloaded and transported to the Vertical Processing Facility on Feb. 6. The telescope was removed from the shipping container on Feb. 8. It was rotated to the vertical position and placed in a test stand on Feb. 10.