Main Proposer Page

What's New in Cycle 21


New Chandra Proposal Software (CPS)

Proposers are required to use the new Chandra Proposal Software (CPS) for all GO proposal submissions in Cycle 21. CPS replaces the Remote Proposal Submission (RPS) used in previous cycles. Chandra proposers are strongly advised to sign up for a CPS account well in advance of the Cycle 21 deadline. Proposers for Director's Discretionary Time (DDT) should continue to use RPS until a DDT version of CPS is available.


Cool Attitude Targets (CATs)

There are significant restrictions on the duration of Chandra observations at many solar pitch angles (see Section 3.3 of the POG). In October 2018 the CXC issued a white paper call for lists of astrophysical objects (Cool Attitude Targets, CATs) that can be included in the schedule to provide spacecraft cooling. The mission planning team started using CATs for spacecraft cooling in December 2018. CAT data does not have associated proprietary time. There are no restrictions on GTO and GO proposers applying for accepted CAT targets. CATs are described in more detail in Section 2.7.5 of the POG and Section 3.11 of this document.


Observing Preferences

Observing preferences (e.g. time windows, roll angles etc) may be requested to enhance the science return of proposed observations (see Section 4.4 for details). Going forward into Cycle 21, the increasing complexity of keeping the spacecraft within acceptable thermal limits will likely result in a drop in the number of preferences that are met. Proposers should explicitly demonstrate that the science goals used to justify the observation will be attainable even if preferences are not met.


LPs and VLPs

A maximum of 1.5 Ms of observing time on targets situated above 60 deg or below -60 deg ecliptic latitude will be available to the BPP for allocation to LPs and VLPs.