News by Date
News by Category
Solar System
Stars
White Dwarfs
Supernovas
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Quasars
Galaxy Clusters
Cosmology/Deep Field
Miscellaneous
Press Resources
Status Reports
Press Advisories
Image Releases
Release Guidelines
Image Use Policy
NASA TV
Biographies/Interviews
Web Shortcuts
Chandra Blog
RSS Feed
Chronicle
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
Related Links

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.
Chandra Resumes Science Operations

For Release: September 7, 2021

NASA/CXC

Chandra

NASA's Chandra X-ray Observatory has successfully resumed observations after recovery from a problem involving one of its science instruments, the Low Energy Transmission Grating (LETG). The LETG is used to measure the intensity of X-rays at different energies.

In preparation for an observing run Aug. 31 using the LETG, the movement of this instrument into its operating position — where it intercepts the path of X-rays — occurred faster than normal, by a fraction of a second. This unexpected timing change caused Chandra's flight software to report that the instrument's movement into operating position had failed. Further motion of the gratings was automatically prevented, resulting in several observations being carried out with the LETG in position, despite not requiring this instrument.

When the next regularly scheduled communication of Chandra with the Deep Space Network on Earth occurred several hours later, staff at the Operations Control Center at the Chandra X-ray Center in Massachusetts were alerted to the problem and stopped observations. Following analysis of the problem, the LETG was successfully moved back out of its operating position. Observations without the LETG resumed Sept. 2. The timing problem with the grating's motion is being investigated before further observations with the LETG or its companion instrument, the High Energy Transmission Grating, will be conducted.

Chandra has been in operation for 22 years, now well into its extended mission. NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science and flight operations from Cambridge and Burlington, Massachusetts.

Media Contacts:

Megan Watzke
Chandra X-ray Center, Cambridge, Massachusetts
617-496-7998
mwatzke@cfa.harvard.edu

Molly Porter
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
molly.a.porter@nasa.gov