The JSTUC has a membership of 10-14 scientists, chosen jointly by the STScI Director and JWST Senior Project Scientist. The composition initially consists of representatives of the JWST Guest Observer community (GOs - 10 members) and members of the JWST Instrument Definition teams (GTOs – 4 members). GTOs are represented on the JSTUC through the period where the bulk of their guaranteed observations are being executed. To allow for balance between continuity and new input, GO members are generally appointed for a three-year term starting on the date of the first meeting attended. The term is specified at the time of appointment. The Director and the Senior Project Scientist can together ask a member to serve for one more year if mutually agreeable. At least two of the GO representatives are astronomers from ESA nations and one is an astronomer from Canada; those members are appointed with ESA and CSA concurrence, respectively.

The JSTUC chair is a member of the JSTUC and is nominated and appointed by the Director and Senior Project Scientist. The term is specified at the time of appointment. The Director, with concurrence of the Senior Project Scientist, can ask the Chair to serve for an additional one-year period.

The JSTUC meets at least twice a year, with the meetings generally hosted by STScI. The STScI Director, the Head of Science Mission Office, the NASA Senior Project Scientist, the NASA Program Scientist, an ESA representative, and a CSA representative attend meetings of the group ex-officio (non-voting). The Associate Director for Science or their designate is the Executive Secretary of the JSTUC.

The scope of the Users Committee is broad. The JSTUC can:

• Set its own agenda
• Establish an ad-hoc subcommittee structure to perform in-depth studies of relevant subjects, if necessary
• Request support from STScI and GSFC for information and clarification

The product of the JWST Users Committee deliberations consists of written reports addressed to the STScI Director and the JWST Senior Project Scientist. These reports (together with an STScI or Project response, if warranted) are made available to Space Telescope Institute Council (STIC) and the Institute Visiting Committee, to NASA and ESA, and to the general community. [Updated June 8, 2020]