CHEOPS  "Frequently Asked Questions" :  Discretionary programme


Below is a collection of Frequently Asked Questions (FAQs), together with answers, relating to the preparation and submission of proposals for CHEOPS Discretionary Programme. The page will be updated regularly to answer questions that come up relating specifically to the programme, including submission of proposals.

If you do not find an answer to the question you have, please review the documentation provided on the discretionary programme webpage. If you still cannot find the answer, then please send an email to

Please note that it may take a few days for questions to be answered, and to be put up onto this webpage.

Incase of problems with the email address noted above, please contact   kate dot isaak at esa dot int, replacing "dot" with "." and "at"  with "@".

Latest update:    16 May 2021


Q5 What is the latest point that an observation request can be submitted AND still included in the NEXT planning cycle?

An activity plan, or observing schedule, covering 1 week of observations is typically uplinked to the spacecraft on a Wednesday or Thursday, and will start to be executed on the Saturday a few days later. Generation of the activity plan itself typically takes a couple of days and starts already on Monday - it should be possible to include new observations requests (ORs) for consideration that have been completed AND have been submitted by the midnight GMT on the day before the planning starts (Sunday).


Q4 To what level of precision do I need to provide target coordinates?

The coordinates for targets for any CHEOPS observation need to be provided in degrees (J2000, icrs) with precision of a minimum of 6 (RA) and 5 (Dec) decimal places. The correct coordinates need to be provided as part of the PHT1 input - directly into the proposal handling tool that you use to submit yiour proposal - as this information is sent directly to the cScience Operations Centre on approval of a proposal, and cannot be updated when preparing observation requests. 


Q3 What is the turn-around time for a proposal submitted to the CHEOPS discretionary programme?

The objective of the discretionary programme (DP) is to enable targets that have been discovered/delared to be of high scientific interest since the close of AO-1 back in May 2019 to be both proposed and (if possible) observed. The earliest possible date that a target could be observed will depend on the turn-around time of proposal, which includes proposal evaluation and then (if successful) the preparation by the PI of the observation request (OR) for the observation(s) themselves AND inclusion in the weekly activity plan/observing schedule. In principle, this could be as short as c. 2-3 weeks, however this will depend on when, in relation to the preparation of the following week's activity plan, an OR can be prepared, submitted and validated.


Q2 What constraints are there on proposals that can be submitted to the Discretionary programme?

Full details, including constraints on the number and type of targets that can be proposed, are provided in the Policies and Procedures document which is available at this link.


Q1 When will the discretionary programme open?

The programme is foreseen to open by mid-July 2020. All details, including tools and documentation to support proposal preparation will be available from the discretionary programme webpage at this link.