Every year, the International Astronautical Federation with the support of the International Academy of Astronautics and the International Institute of Space Law (IISL), holds the International Astronautical Congress (IAC) which is hosted by one of the national society members of the IAF. They are an annual meeting of the actors in the discipline of space, and are generally held in late September or early October. They consist of plenary sessions, lectures and meetings. The IAC is attended by the agency heads and senior executives of the world's space agencies.