News by Date
News by Category
Solar System
White Dwarfs
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Galaxy Clusters
Cosmology/Deep Field
Press Resources
Status Reports
Press Advisories
Image Releases
Release Guidelines
Image Use Policy
Web Shortcuts
Chandra Blog
RSS Feed
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
Chandra @ NASA
Visit the Chandra pages at the NASA portal (opens in new window)
Image Use
Image Use Policy & Request Form
Guidelines for utilizing images, applets, movies, and animations featured in this Web Site.
Operations CXO Status Report

Sunday 15 August 1999 7.00am EST

The following is an overview of the events that occurred over the last 24 hours

Offline System (OFLS) scheduling of mission loads. - Started performing maneuvers and test observations controlled from onboard Real Time Sequences (RTS) derived in the OFLS instead of real time ground commands. This load was to control the Chandra until about midnight Sunday. During maneuvers experienced problems acquiring FID lights and stars. During one maneuver Chandra did not acquire scheduled guide stars, and as designed dropped into bright start hold mode, by locking onto bright stars in the Aspect Camera field of view. As expected, on-board mission Stored Command Sequences (SCS) were also terminated. Further analysis indicated that the logic in the On Board Computer (OBC) needs to be corrected to allow the Aspect Camera to release and reacquire guide stars based on maneuver requirements. Activities are underway to correct these problems, and re-enter the OFLS mission scheduling within 24 hours. In the meantime, Chandra activities are being be performed via real time commands.

ACIS focusing activities are in progress. As part of this activity the Science Instrument Module (SIM) underwent successful movements in the focus direction. This is the first time this mechanism was exercised since launch. Movement of the SIM Translation mechanism is planned in a few days.

Activities for next 24 hours
  • Continue on-board RTS directed Chandra operations.

Return to Status Reports