Due to heavy demand and the need for scheduling flexibility in Cycle 22, Large GO
programs requesting 75 orbits or more must use the shorter orbital visibility values from Table 6.1
; this will be enforced for such programs approved for Phase II.
By the start of Cycle 22, COS FUV spectroscopy is expected to have moved from the
second COS Lifetime Position (LP2) to the third (LP3) in order to ameliorate the continuing effects of gain sag. While the exact change in performance is not yet known, typical spectral resolution (λ/Δλ) may decline by about 15%. Depending on the details of the LP3 implementation, it is possible that the resolution decline for the COS FUV G140L grating may be somewhat larger. The resolution values, quoted in Section 4.4
include an approximately 15% resolution degradation. Instrument performance is otherwise expected to be similar to that seen during Cycle 21. Updated information will be provided to the community as it becomes available.