These contracts, to run for about five months, were to include the several companies' proposals for accomplishing the payload integration effort for all AES flights and would form the basis for NASA's final choice e of integration contractors. Current plans, Gray said, were based on selection of two such payload integration contractors, one at MSC and the second at MSFC, each responsible for about half of all AES Rights. (During the integration definition phase contracts, however, MSC had lead responsibility for competition and selection of study contractors, with participation by MSFC and KSC. Gray authorized MSC to supplement the existing AES study contracts with North American and Grumman to assist in the payload integration definition effort.)