Retirement of CCD Module 4 confirmed

News article posted on by Geert Barentsen

As reported in detail in the latest Kepler Mission Manager Update, additional spacecraft telemetry appears to confirm the loss of CCD Module 4 during K2's current Campaign 10.

Module 4 is the third of the 21 science modules to have failed in-flight. Such hardware failures were foreseen in the initial mission planning, and the system design is robust and compartmentalized to minimize the impacts. After more than seven years in the harsh conditions of space, 85 percent of Kepler's original detectors are still operating.

Campaign 10 science observations were interrupted between July 20 and August 3 as a result of the anomaly. Observations have since returned to normal and no further interruptions are expected.

Impact on GO programs

For the K2 mission’s current Campaign 10, the targets that fell on Module 4 will yield no data beyond July 20. For all campaigns going forward, we will only allocate pixels to targets which fall on one of the remaining 18 operational modules.

On average 4% of the targets requested by selected GO programs fell on the retired Module, with no single program affected by more than 20%.

The pixel storage budget that would have been used by Module 4 during future Campaigns will be re-allocated to other Modules, allowing the total number of K2 targets to remain unchanged. The impact on science is expected to be small as a result.

None of the high-profile targets in future Campaigns, such as Trappist-1 or Comet Chiron, are known to be affected. Investigators who are concerned about a particular target are encouraged to contact us at

Where is Module 4?

The ill-fated Module is located on the outside of the focal plane, where both the pointing stability and the point spread function are less ideal. Its position is marked using a pen in the photograph below:

Module 4 contains channel numbers #9, #10, #11, and #12.

K2fov update required

The due date for K2 Cycle 5 proposals for targets to be observed in Campaigns 14, 15, and 16 is just over a month away. The K2fov target selection tool has been updated to version 5.1 to incorporate the loss of Module 4.

All candidate investigators must upgrade to this new version. Instructions for updating your installation of K2fov are provided on the proposal preparation page.