On the evening of October 24th during a real time contact in which the HRC-S was scheduled to be observing V1935 Cen, the HRC team noted that the HRC-S High Voltage Power Supply was OFF, when it should have been ON. This anomalous detector state led the team, in consultation with the Flight Director and Lead Systems Engineer, to manually command the HRC into a safe state. All other spacecraft and detector telemetry appeared nominal at the time. The HRC remains inactive while the instrument and operations teams diagnose the issue.

11/4/25

This upgrade includes the following items:

• ACIS T_GAIN file set covering 2022 through 2024
• HRC-S QE Uniformity file set version N0022

See the full announcement for more detail.

8/19/25

Lists of targets recommended by the Cycle 27 Peer Review are now posted.

This page includes separate lists of:

• recommended time on joint partner observatories,
• recommended programs that use Chandra time from multiple cycles,
• recommended Large Project and Very Large Project proposals, and
• overall statistics of the Cycle 27 program.

7/29/25