This page describes several "Special Initiatives" which highlight the unique capabilities possessed by JWST. STScI especially seeks proposal that fall into one of these initiatives.

Long-Term Monitoring (LTM) initiative

Time-domain astronomy was highlighted as a key priority in the Astro2020 Decadal Survey. While much attention focuses on short-term transients, JWST’s projected 20-year lifetime provides an opportunity for investigations on substantially longer timescales. With that in mind, STScI constituted a Working Group to explore options for how JWST can better support science in this area. The Working Group’s report highlights a number of areas where JWST can make significant contributions.

The community is encouraged to submit proposals that:

• Capitalize on past JWST observations by providing later-epoch observations that are designed to probe long-term astrometric, photometric, and/or spectroscopic variations.
• Propose first-epoch observations to lay the foundation for future time-domain work with either JWST or HST, including a justification of the expected cadence. The TAC will be instructed to assess the science impact of the full program, not just the current cycle observations. Proposers may submit joint JWST-HST proposals that request either or both JWST and HST observations in current and future cycles.
• Request observations beyond the 3-cycle limit for Future Cycles programs, up to 5 cycles.

LTM programs will be regularly monitored to ensure appropriate progress on scientific objectives, but if approved, they will not be subject to TAC review for future observations.

LTM programs may be GO, Survey, or AR proposals.

No extra time is made available for LTM Initiative proposals, and no additional weight is given in grading. However, setting the LTM flag serves to highlight JWST's projected longevity and its importance for time-domain astronomy during the review. Proposals must still justify why JWST is required to achieve the program's science goals, as described under the JWST How Your Proposal is Evaluated. LTM proposals recommended for acceptance must meet the usual requirement of high scientific quality set for all successful JWST proposals.

Additional APT requirements

Proposers must check the "Long-Term Monitoring" box on the APT Proposal Information form to identify that their proposal qualifies for this initiative. GO proposers must then also fill in the appropriate information under the Future Cycles pull-down menu in APT.

Additional PDF attachment requirements

Proposers must specify the required cadence of observations in the "Special Requirements" section of the PDF attachment.

How these proposals are reviewed

LTM proposals are subject to the same review process as regular proposals of the same type or size category. For Future Cycle GO LTM programs, the sum of all hours requested in all cycles determines whether the proposal is Very Small, Small, Medium, or Large. GO LTM proposals have the same default Exclusive Access Period as regular GO programs of the same size.

JWST-Roman Science (JRS) initiative

The Nancy Grace Roman Space Telescope (Roman) is planned to launch on August 30, 2026. Roman will provide wide-field survey data including imaging and slitless spectroscopy spanning the wavelength range 0.5 to 2.3 μm, and direct imaging data from 0.5 to 0.8 μm of exoplanets using the high-contrast coronagraph instrument.
 
The JRS Initiative is designed to encourage observations with JWST that complement and enhance the scientific impact of Roman observations, or that are essential to achieving critical science goals of Roman programs.

The connection between the proposed JWST and Roman observations will be considered as part of the review process. Where the JWST observations are deemed essential to achieving the overall science goals, the proposal will be assessed based on the science expectations for the full program including both the JWST and Roman observations. Requests for non-zero Exclusive Access Period data will also be assessed by the TAC.

JRS programs may be GO, Survey or AR.

No extra time will be made available for JRS Initiative proposals, proposals cannot request Roman time, and no additional weight will be given in grading. However, setting the JRS flag serves to highlight JWST's broad impact and its importance for future science with Roman during the review. Proposals must still justify why JWST is required to achieve the program's science goals, as described under the JWST How Your Proposal is Evaluated. JRS Initiative proposals recommended for acceptance must meet the usual requirement of high scientific quality set for all successful JWST proposals.

Additional APT requirements

Proposers must check the "JWST-Roman Science (JRS)" box on the APT proposal information page to be included in this initiative.

Additional PDF attachment requirements

Proposers should use the "Special Requirements" section of the PDF attachment to describe the connection with specific Roman observations.

If the JWST observations are critical to the success of a Roman program, the science goals of the full program should be described in the "Scientific Justification," including an explanation as to why JWST observations are deemed essential to achieve those goals.

By default, JRS proposal data will not have an Exclusive Access Period. A non-zero Exclusive Access Period may be requested, and should be justified in the "Special Requirements" section of the PDF attachment. 

How these proposals are reviewed

JRS proposals are subject to the same review process as regular proposals of the same type or size category.

Habitable Worlds Observatory Precursor Science (HPS) initiative 

The Habitable Worlds Observatory (HWO) is a large infrared/optical/ultraviolet space telescope recommended by the National Academies’ Pathways to Discovery in Astronomy and Astrophysics for the 2020s. HWO will be the first telescope designed specifically to search for signs of life outside our solar system, however its powerful capabilities will transform a broad range of fields across astrophysics, as reflected in the HWO Community Science Case Development Documents.

The HPS Initiative is intended for investigations with JWST that will support HWO science planning to inform mission architectures and trades, with the goal of reducing the cost and risk of HWO’s future design and development. Leveraging JWST's capabilities now is therefore essential to inform key aspects of HWO science planning and maximize the eventual return of the mission.

HPS programs are expected to generate knowledge, methods, or data that:

• constrain astrophysical parameters critical for HWO target selection, instrument design, or observational strategies,
• provide essential empirical inputs for science programs that HWO aims to address, or
• develop analysis techniques and data products that can be applied or scaled to HWO observations.

HPS programs may be GO, Survey, or AR proposals.

Additional APT requirements

Proposers must check the “HWO Precursor Science (HPS)” box on the APT proposal information page to be included in this initiative.

Additional PDF attachment requirements

The "Special Requirements" section of the PDF attachment should explicitly describe the link to specific HWO precursor studies, Science Case Development Documents, anticipated HWO observations, or technical trades.

If JWST observations are critical to HWO planning or its future success, the "Scientific Justification" section should describe the relevant HWO science goals and explain why JWST data are essential for de-risking or enabling those goals.

By default, HPS proposal data will not have an Exclusive Access Period. A non-zero Exclusive Access Period may be requested, and should be justified in the "Special Requirements" section of the PDF attachment. 

How these proposals are reviewed

HPS proposals are subject to the same review process as regular proposals of the same type or size category, with the additional selection criteria to be considered:

• The strength of the connection to HWO planning and development needs will be explicitly considered during the review. Where the JWST observations are deemed essential to achieving long-term HWO science goals, review panels will evaluate the proposal in the context of the combined JWST + HWO programmatic impact.

• Proposals must still demonstrate why JWST is required to achieve the program's science goals, as described under the JWST How Your Proposal is Evaluated.

• No extra time will be made available for HPS Initiative proposals, and no additional weight will be given in grading.

• Requests for non-zero EAP data will be assessed by the TAC.

HPS Initiative proposals recommended for acceptance must meet the same high standards of scientific excellence expected of all JWST programs. Highlighting them within the HPS framework will underscore JWST's unique role to inform planning, reduce risk, and maximize the eventual scientific return of HWO.

Next: JWST Observations Needing Special Requirements