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About COS Calibration Programs

Calibration programs will monitor COS performance and will provide information needed to calibrate supported observing modes. Each cycle, a set of calibration programs will be assembled and approved by the Director. The following is a table of all the calibration plans.

The summary tables contain the list of all the calibration programs for each cycle. The final calibration plans describe briefly the purpose, accuracies, and resources for each of these programs. The results and status of the calibration programs at the end of each cycle will be documented in the closeout reports.

Calibration Program Summaries

Cycle Summary Calibration Plans Closeout Reports
Cycle 31

Cycle 31 Final Plans (No Changes)

Cycle 31 Final Plans (Changes)

Cycle 30

Cycle 30 Final Plans (No Changes)

Cycle 30 Final Plans (Changes)

Cycle 29

Cycle 29 Final Plans (No Changes)

Cycle 29 Final Plans (Changes)

Cycle 28 Cycle 28 Final Plans (All Programs)  
Cycle 27 Cycle 27 Final Plans (All Programs)

ISR 2021-04

Cycle 26

Cycle 26 Final Plan (All Programs) ISR 2020-01
Cycle 25 Cycle 25 Final Plan (No Changes)
Cycle 25 Final Plan (All Programs)
ISR 2019-20
Cycle 24 Cycle 24 Final Plan (Changes)
Cycle 24 Final Plan (All Programs)
ISR 2020-10
Cycle 23 Cycle 23 Final Plan ISR 2016-04
Cycle 22 Cycle 22 Final Plan ISR 2016-03
Cycle 21 Cycle 21 Final Plan ISR 2015-06
Cycle 20 Cycle 20 Final Plan ISR 2015-02
Cycle 19 Cycle 19 Final Plan ISR 2014-01
Cycle 18 Cycle 18 Final Plan ISR 2013-04
Cycle 17 Cycle 17 Final Plan 
Cycle 17 Final Supplemental Plan
ISR 2012-02


COS Airglow Observations

The COS team has provided high-S/N observations of the geocoronal Lyman-alpha line profile observed with the G130M and G140L gratings in previous calibration cycles. These observations allow users to model and subtract the line wings from their spectra.

These programs were discontinued after Cycle 24 in accordance with the COS 2025 policy, which aims to protect and extend the lifetime of COS in part my severly limiting the instrument's exposure to Lyman-alpha airglow. 

We provide a listing of both deliberate and accidental airglow observations on the COS Airglow page. You can also find community generated observational templates for four geocoronal emission lines at the bottom of the page. If you discover any others, please let us know. In addition, we have posted a list of airglow lines observed in FUSE and HUT data which may be present in COS observations.

Last Updated: 06/07/2024


HST Help Desk 

Please contact the HST Help Desk with any questions.