September 9, 2020

About This Article

STScI recognizes that the COVID-19 pandemic has been an extremely challenging time, especially for those directly impacted by the virus and for families caring for dependents. STScI set a new JWST Cycle 1 proposal deadline of November 24, 2020 – with more than 17 weeks advance notice to further help mitigate the effects of the pandemic. In response to feedback from the community, the JWST Users Committee recommended that STScI should also offer an opportunity for individuals to appeal for a later deadline on a case-by-case basis. This contingency mechanism is meant to alleviate the impact of hard-to-plan-for events, such as illness, changes in childcare status, or the sudden shut-down of in-person teaching. STScI has now released a new policy for deadline extension appeals. For more information, see the policy in the Call for Proposals.

What Happens after the Deadline?

The proposal deadline is bounded by the new JWST Target Launch Date on October 31, 2021 and by the time needed to accommodate the:

  1. Assignment of proposals to reviewers by STScI staff
  2. Scientific review of the proposals by members of the scientific community
  3. Technical review of the proposals by STScI staff

Here is more information about the technical process from proposal submission to Cycle 1 science operations, and how the timeline is constrained.

Scale of the Cycle 1 Program

The size of the Cycle 1 program is substantial. Up to 6,000 hours of JWST time are available to General Observers in Cycle 1. With 3,800 hours already allocated for already approved Guaranteed Time Observer (GTO) observations and 460 hours for the Director’s Discretionary Early Release Science (DD-ERS) observations, this totals more than 10,000 hours of science observations.1 STScI anticipates that approximately 300 individual GO proposals will be approved for Cycle 1. The GO, GTO, and ERS programs will begin executing right after commissioning, on equal terms to provide the widest possible section of the community with data before the GO Cycle 2 deadline.

Program Selection

The estimate of the time needed for the JWST GO Cycle 1 selection is based on experience with the Hubble Space Telescope, which follows a similar process. After the Cycle 1 deadline, STScI staff will assign proposals to panels in the JWST Time Allocation Committee (TAC) for scientific review. The proposals are verified as complete before being assigned to science review panels. Proposals are then assigned to individual reviewers, matching scientific experience and balancing work load. STScI anticipates that as much as 3 weeks is needed to classify and assign more than 1,000 submitted proposals.

Members of the TAC are also impacted by the COVID-19 pandemic. Consequently, STScI will distribute the proposals to reviewers before the winter holidays to provide them with as much time as possible for their preliminary evaluations. Reviewers will read all submitted proposals and write summary reports of science goals, strengths, and weaknesses on their assigned proposals prior to the panel meetings. STScI anticipates that each panel will evaluate approximately 60-90 proposals, with each reviewer grading approximately 50-60 proposals. For Hubble TACs, STScI typically provides panelists with at least 6 weeks to read and submit preliminary grades. STScI requires an additional 10 days prior to the TAC to produce a preliminary ranking for triage before the TAC meeting.

The TAC meeting will be virtual. It includes about 200 members of the JWST Observer community, who will meet in 20 panels over a two-week period. The super-TAC, comprised of the panel chairs, will convene in the third week. To minimize the impact on reviewers, as well as other major facilities that also organize proposals reviews, STScI avoids scheduling the TAC meeting at a time that overlaps with other proposal deadlines. For instance, the NOIRLab and ESO proposal deadlines typically fall at the end of March; the Chandra deadline typically falls in mid-March; and the Hubble deadline typically falls at the beginning of April. Therefore, the JWST GO Cycle 1 TAC has been scheduled for mid-February to early-March.

Once the TAC review is complete, a recommendation is sent to the STScI Director for formal selection. At this time, the selected proposals are checked for duplications and other programmatic issues. This process takes about 2 weeks, and STScI anticipates to announce the final Cycle 1 GO program in the second half of March.

Technical Reviews of Selected Proposals

In order to develop an executable science program for Cycle 1, STScI will conduct a technical review of each individual proposal. As a first step, proposers will resolve residual warnings and finalize the proposals. The subsequent reviews will ensure that the technical designs of the proposals use best practices, are adequately matched to the proposed science, and optimize observatory efficiency. JWST is a new observatory and the community is still learning how to use it; it is expected that almost all proposals will require some adjustments. STScI instrument experts will work closely with observers to implement any necessary changes.

The technical reviews represent a major effort by STScI staff. Allowing for adequate time to communicate and work through the revisions with the proposers is essential. STScI staff tasked with conducting technical reviews will also be needed for instrument commissioning after launch. Therefore, all of the technical reviews of the proposals must be completed before the Target Launch Date.

Based on experience reviewing GTO and ERS proposals, STScI anticipates that this process will take 4 months or more, depending on the nature and complexity of the selected program. Some instrument modes are particularly complex and may require more extensive review, including multi-object spectroscopy with NIRSpec, or observations with timing or orient constraints.

Once the science program has been finalized, STScI staff will review the Cycle 1 Calibration Plan to ensure that it adequately supports the selected science program, and implement any necessary changes. STScI estimates that it will take an additional 1 month to update the Calibration Plan.

Cycle 1 science timeline


1 It is necessary to oversubscribe JWST observations in order to ensure efficient scheduling. All programs not completed in Cycle 1 will carry over to Cycle 2.


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