STScI especially seeks proposals that fall into one of several "Special Initiatives," described below. These initiatives highlight the unique science capabilities possessed by JWST.

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. Consequently, STScI is inaugurating the LTM Initiative.

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 Cycle programs, up to 5 cycles. Proposers must specify the required cadence of observations in the "Special Requirements" section of the PDF attachment.

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.

Proposers must check the "Long-Term Monitoring" box on the APT Proposal Information form to identify that their proposal qualifies for this initiative.

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 Proposal Selection Procedures. LTM proposals recommended for acceptance must meet the usual requirement of high scientific quality set for all successful JWST proposals.

Roman Preparatory Science (RPS) Initiative

The Nancy Grace Roman Space Telescope (Roman) will launch no later than May 2027, with a first call for proposals in Fall 2025. Roman will provide wide-field survey data including imaging and slitless spectroscopy spanning the wavelength range 0.5 to 2.3 microns and direct imaging data from 0.5 to 0.8 microns of exoplanets using the high-contrast coronagraph instrument.
 
The RPS 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 future Roman programs.
 
RPS Initiative proposals should comply with the following guidelines:

• Proposers must check the “Roman Preparatory Science” box on the APT proposal information page to be included in this initiative.
• 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 the future 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, RPS proposal data will not have an Exclusive Access Period (EAP, a default of zero months). A non-zero EAP may be requested, and should be justified in the "Special Requirements" section of the PDF attachment. 

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 EAP data will also be assessed by the TAC.
 
No extra time will be made available for RPS Initiative proposals, and no additional weight will be given in grading. However, setting the RPS 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 Proposal Selection Procedures. RPS Initiative proposals recommended for acceptance must meet the usual requirement of high scientific quality set for all successful JWST proposals.

Next: JWST Observation Types