Background on the GLAST Guest Investigator Program

As for other NASA missions, the GLAST Guest Investigator (GI) program will determine the mission's observing plan after the first year of science operations and will fund GLAST-related research.

GIs May Propose Observations After the First Cycle, But Funding Proposals Will (Probably) Predominate:

While observations may be proposed through the GI program, the typical GI proposal will most likely be for funding only. The LAT's field-of-view is very large and, while the LAT's effective area is much larger than earlier gamma-ray missions, the flux of astrophysical gamma rays is low enough that the detection of all but the strongest sources will require very long observations. GLAST's default observing plan is a survey mode where the LAT's pointing is offset 35 degrees from the zenith perpendicular to the orbital plane; once per orbit the pointing is rocked to the opposite side of the orbital plane. Between the rocking once per orbit and the ~55 day precession of the orbit, the sky is observed uniformly. Thus survey mode will satisfy the needs of most scientific investigations while the utility of pointed observations will usually be small, and the GI program is very unlikely to fill GLAST's observing plan with traditional pointed observations.

However, observations may be proposed, although the justification must be compelling. Some sources will benefit from the more rapid accumulation of exposure resulting from a pointed observation. Deep exposures of the Galactic Poles or Center might extend the AGN luminosity function or improve pulsar detectability. Special survey modes, e.g., 'sliding' along the Galactic Plane, might be efficient.

Mission Phases and GI Program Cycles:

The mission is required to last 5 years with a goal of 10 or more years (there are no expendables). It will consist of three phases:

Phase 0—the 60 days during which the spacecraft and instruments are turned on and checked.
Phase 1—the first year of science observations. During this year the instrument teams verify the operation of their instruments while the LAT surveys the sky. The LAT event data are proprietary to the LAT instrument team and the Interdisciplinary Scientists (see the GLAST data policy). GIs may not propose to alter the observing plan. The LAT team will post the lightcurves of ~20 bright sources, as well as information on bright transients (see the summary of the data the LAT instrument team will release during the first year). GBM burst data will become public as soon as processed.
Phase 2—the rest of the mission until the spacecraft is de-orbited. During Phase 2 the data are not proprietary, and are released as soon as processed. The observing plan is driven by the GI program. The LAT team will continue to monitor and post the lightcurves of ~20 bright sources, and information on bright transients.

During Phases 1 and 2 there will be annual GI program cycles. Only ~50 GI proposals will be accepted in Cycle 1, which will coincide with Phase 1, while ~100 proposals will be accepted in subsequent cycles (Phase 2).

The Mechanics of the GI Program:

The NASA Research Announcement (NRA) for GLAST will be part of NASA's yearly Research Opportunities in Space and Earth Sciences (ROSES). The ROSES is usually released at the end of January, with the deadlines for the different programs covered by the ROSES staggered throughout the year. The deadline for the Notice of Intent (NOI), which is strongly recommended but not absolutely required, is ~2 months before the deadline for the actual proposal. The ROSES itself will include general instructions for all programs and a brief description of the GLAST GI program and its requirements. The ROSES is a legally binding document.

About 3 months before the proposal deadline additional materials will be posted on the GSSC website. These will include descriptions of the instruments, analysis tools and proposal preparation tools, as well as detailed instructions for proposal submission.

A two stage proposal process is planned. The first stage proposal will provide the observing request (if any), the scientific justification and an estimate of the desired funding. The second stage proposal will justify the funding request and will be solicited and submitted only if the first proposal is accepted.

There will always be a webpage for the upcoming cycle.

Questions about the use of these tools to simulate GLAST observations or prepare GI proposals should be submitted through the GSSC help desk.