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

Friday 14 August 2009 9.00am EDT

During the last week Chandra completed the observing schedule as planned.

A real-time procedure was conducted on August 10 to uplink a flight software patch to the OBC grating insertion/retraction code to avoid using the state of the faulty HETG retract limit switch. This patch is to resolve the July 7 anomaly in which the OBC grating "move failed" flag was set. The real-time procedure also cleared the flag. Completion of this procedure re-enables the use of the gratings for observations. A follow-on real-time procedure was conducted on August 13 to perform a routine dump of the OBC memory to maintain a ground record of the on-board version.

In response to the ongoing MUPS tank anomaly investigation, a real-time procedure was conducted on August 12 to enable automatic momentum unloads if the spacecraft angular momentum exceeds 40 ft-lb-s. The step was taken as a precautionary measure in the event that the pressure drop is due to a leak, and provides an auto unloading capability as an early level of protection against a leak-induced momentum disturbance instead of relying on safe-mode.

The investigation into the cause of the MUPS tank pressure reading drop has continued with the prime candidate for the root cause thought to be faulty sensor readings but with a leak not ruled out. Since the drop in readings appeared to increase with temperature of the MUPS, spacecraft attitudes have been restricted to those that minimize the temperatures of the MUPS tank and fill panel. This restriction of attitudes has necessitated modification of the planned long-term schedule and resulted in the earlier than expected use of cycle 11 targets, requiring extensive coordination with observers. The engineering team is developing detailed plans and products for performing a firing of the MUPS thrusters in order to measure the impulse that they generate as a secondary determination of the MUPS tank pressure.

A Chandra image release was issued on August 12 of Cepheus B. The composite image, combining data from the Chandra X-ray Observatory and the Spitzer Space Telescope shows the molecular cloud Cepheus B, located in our Galaxy about 2,400 light years from the Earth, a place where stars are known to form. For further details see:

On August 13 the CXC launched a redesigned version of the top-level science web page:

The schedule of targets for the next week is shown below

ESO243-49HLX-1         HRC-I        Aug 17
Radiation Belts
Abell2631              ACIS-I       Aug 18
A2645                  ACIS-S
Abell2627              ACIS-S
PSRJ1907+06            ACIS-S       Aug 19
4U1901+03              ACIS-I
NGC6868                ACIS-I
Radiation Belts                     Aug 20
ES1-351                ACIS-S
UGC408                 ACIS-S       Aug 21
SN2001em               ACIS-S       Aug 22
Radiation Belts                     Aug 23
IRAS00397-1312         ACIS-S


All spacecraft subsystems continued to support nominal operations.

Return to Status Reports