The Hubble Space Telescope Primer for Cycle 30

The HST Primer provides an introduction to the Hubble Space Telescope for Phase I proposers.

About This Document

The Hubble Space Telescope (HST) Primer for Cycle 30 is a companion document to the Hubble Space Telescope Call for Proposals for Cycle 30. It provides an overview of HST, with basic information about telescope operations, instrument capabilities, and technical aspects of the proposal preparation process. A thorough understanding of the material in this document is essential for the preparation of a competitive proposal. The Call for Proposals discusses the policies and procedures for submitting a Phase I proposal for HST observing or archival research. Technical documentation on the instruments are available in their respective handbooks, available on the HST Document overview site.

Late Breaking News

    • Jan 6, 2023: HST Cycle 30 is extended by 2 months (through November 30, 2023). Correspondingly, HST Cycle 31 will be shortened by 2 months (running December 1, 2023 through September 30, 2024). We anticipate releasing the HST Cycle 31 Call for Proposals on March 1, 2023, with a Phase I proposal deadline of Wednesday May 24, 2023 at 8pm EDT.
    • Feb 15, 2022: To avoid clashes between HST Cycle 31 activities and JWST Cycle 2 activities, it is likely that HST Cycle 30 will be extended by 2 months (through to November 30, 2023), and the orbit allocation for Cycle 30 increased by up to 500 orbits. A final decision will be made towards the end of JWST commissioning, prior to the HST Proposal Review. As usual, the orbits will be distributed proportionately among the proposal categories. For more information, see the February 2022 JSTUC presentation.
    • Feb 14, 2022: APT 2022.1 was released on Feb 11. Cycle 30 proposers should use this version to submit their proposals. Submissions started in earlier versions can be transferred to 2022.1.
    • Jan 20, 2022: APT 2022.1 or later must be used for Cycle 30 proposal submissions. This will be released by mid-February. We will alert the community as soon as it is available.
    • Jan 11, 2022: Long-term GO programs may only include non-disruptive ToOs for execution in future cycles.

See also HST New and Important Features.

Proposing Calendar and Deadlines

  • Cycle 30 Phase I proposal deadline: March 25, 2022 at 8:00pm EDT

  • Cycle 30 Peer Review: June 1-8, 2022

  • Cycle 30 Phase II proposal deadline: July 14, 2022

  • Cycle 30 Budget deadline: August 4, 2022 at 8:00pm EDT

  • Cycle 30 1st Mid-Cycle Deadline: October 21, 2022 at 11:59pm EDT

  • Cycle 30 2nd Mid-Cycle Deadline: February 17, 2023 at 11:59pm EST

Where to Get Help

Submit questions to the HST Help Desk at See for additional tools and resources.

Who's Responsible

The HST Call for Proposals and related materials for Cycle 30 were edited by John Debes and Laura Watkins. The Associate Director for Science, Neill Reid, and the Science Mission Office at STScI are responsible for the oversight of the HST science program selection process, whose members include Alessandra Aloisi (Head of Science Mission Office), John Debes (Deputy Head of Science Mission Office), Claus Leitherer (Head of Hubble Space Telescope Science Policies Group), Katey Alatalo, Christine Chen, Andrew Fruchter, Amaya Moro-Martin, Molly Peeples, Jamila Pegues, Linda Smith, Laura Watkins, and Technical Manager Brett Blacker.

Next: HST Primer: Resources, Tools, and Other Documentation