The HST General Observer proposal process is divided into two Phases. Phase I proposals contain a scientific justification and abbreviated technical specifications for review by the Telescope Allocation Committee in a particular Cycle. Phase II proposals provide many more technical details for programs recommended by the TAC and approved by the STScI Director for implementation. The information required by proposers in Phases I and II is provided in several extensive documents which are linked by the left sidebar in the specific discussions of each Phase below. These discussions also provide links to key information from those documents, to facilitate rapid access to it by proposers.
Further links to information about HST proposing in general can be found on the HST Proposing Overview page. The Astronomers Proposal Tool is the main utility for creating HST programs.