You can apply more than once and to multiple ESA calls, if each proposal meets the eligibility criteria and fits within the objectives of the specific programme line or funding call. You may submit more than one proposal to ESA, either for different projects or at different development stages. ESA encourages continued participation; many successful missions evolve through sequential phases or multiple funding lines.
You can apply to different open Invitations to Tender (ITTs) under programmes, provided each proposal is distinct and relevant to that call’s scope. Proposals cannot duplicate previously funded ESA work unless clearly justified as an evolution or extension.