TITLE:   GCN CIRCULAR
NUMBER:  31500
SUBJECT: Swift currently in safe hold with science slews disabled
DATE:    22/01/19 21:29:50 GMT
FROM:    Brad Cenko at NASA/GSFC  <brad.cenko@nasa.gov>

On the evening of Tuesday, January 18, NASA's Neil Gehrels Swift Observatory entered into a safe hold, temporarily suspending pointed science observations. The mission team is investigating a possible failure of one of the spacecraft’s six reaction wheels as the cause.

The team has powered off the suspected wheel. The observatory and all its instruments are otherwise operating as anticipated. The observatory will remain in safe hold as a precaution while the team further investigates the issue.

Swift has a total of six reaction wheels onboard. The team is working to restore science operations using the five remaining wheels, which are all behaving as expected. The time scale for implementing this change to operations is currently unknown, and so we are disabling target-of-opportunity submission for the time being. 

We will do our best to provide updates to the community as soon as is practical as the observatory returns to science operations, via GCN and/or Swift's website (swift.gsfc.nasa.gov).

If you have further questions, please feel free to reach out to the Swift PI, Brad Cenko, at brad.cenko@nasa.gov