The majority of the ISO observing time (called Open Time) will be made available to the community via the traditional process of proposal submission and peer review. Observing time will be allocated on a ``per observation'' basis as was the case for EXOSAT, and not on a ``per shift'' basis as it is the case for many ground-based observatories and for IUE.
The Call for ISO Observing Proposals will be issued in April this year, about 18 months before launch. With the Call, observers will receive a number of documents which describe the policies and procedures of the observatory, the Guaranteed Time programme and which give detailed information about the satellite and the instruments, including the various operating modes.
The Call will solicit proposals for the entire mission. To give the possibility to modify, extend or re-direct existing Open Time programmes, a Supplemental Call is planned to be issued during the mission.
There will be two phases of proposal submission:
Prior to submitting a proposal, astronomers will be asked to submit a Letter of Intent, with a due date of early June. This should include the scientific area(s) and brief description of the scientific case(s) and observations envisaged. Only astronomers who submit such a letter will receive IRPSS (by ftp) and any updates on the observing facilities. At the Science Operations Centre, the information provided in the Letters of Intent will be used to refine the procedures of handling proposals during the two phases and those concerning the review.
The application procedure will be slightly different for proposals originating in Japan or the USA. For example, IPAC will host phase 2 data entry for US proposals.
All who received a copy of this newsletter directly addressed to them will automatically receive the full Call for ISO Observing Proposals, with all documentation.