All open time proposals will be reviewed by the Observing Time Allocation Committee (OTAC). This committee is appointed by the Director of ESA's Scientific Programme. It is headed by an overall Chairman and consists of seven panels, one for each of the following scientific areas: Solar System, Interstellar Matter, Stellar Physics, Circumstellar Physics, Extragalactic (Normal and Starburst Galaxies), Extragalactic (Active Galaxies and Quasars) and Cosmology. Each panel consists of a Panel Chairman and, depending on the scientific area, between 3 and 5 members. Note that proposers in their proposal must specify which panel they consider should address their proposal. During their work, the panels will be assisted by SOC staff.