Hubble Space Telescope Call for Proposals for Cycle 32

STScI solicits proposals for HST Observing, Archival, and Theoretical Research. The full details are made available through two documents, the Call for Proposals, and the HST Primer. Downloadable PDF collections of these articles are provided as a courtesy, made available and updated when feasible. The online documentation is the authority, and will be updated with the latest information.

Late Breaking News

  • Wednesday March 6, 2024:
    • Duplications of Carry-Over ToOs: Where new ToO requests duplicate ToOs in programs from previous cycles, triggers from the previous-cycle ToOs have priority over the newly-proposed ToOs.  Proposers must identify and justify any requests for duplicate ToOs.  For more information, see Carry-Over ToOs. 
  • Tuesday March 5, 2024
    • The Hubble Advanced Spectral Products (HASP) initiative transforms the accessibility and utility of archival Hubble Space Telescope (HST) data by automating the coaddition and abutment of one-dimensional spectra from the Cosmic Origins Spectrograph (COS) and Space Telescope Imaging Spectrograph (STIS). HASP provides data products at both visit and program levels, covering all COS and STIS spectra, for each CENWAVE and grating. This service is regularly updated with the latest calibrations and new data from over 3200 programs and 64000 datasets. Additionally, HASP enables users to perform custom coadditions through interactive Jupyter Notebooks. For more details, visit the HASP webpage or Instrument Science Report.
  • Monday February 5, 2024:
    • Consecutive Observations: If your observations require a string of more than 6 consecutive orbits, that string will execute at shared risk (i.e., it will not be eligible for repeat if impacted by observatory problems).  Please consider alternative observational approaches to achieve your science goals.
    • Special Requirements: Given the current performance of the Hubble pointing control system, we remind proposers that all special requirements (such as timing and orientation constraints) not requested and justified in Phase I are implemented only under exceptional circumstances.  If this renders a science program infeasible, the program risks termination.
    • HST-JWST Joint Programs: New this cycle, we require JWST APT files to be submitted for joint HST-JWST programs. Failure to do so will result in disqualification of the proposal. See Joint HST-JWST Observing Programs and Joint HST-JWST Observations for more information.

See also HST New and Important Features.


We invite scientists to participate in Cycle 32 of the Hubble Space Telescope (HST). The telescope and its instruments were built under the auspices of the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). Management of HST’s scientific program is carried out by the Space Telescope Science Institute (STScI). We anticipate allocating up to 3200 orbits in this cycle, including approximately 1600 orbits for Small Programs, 800 orbits for Medium Programs, and 800 for Large and Treasury Programs. An additional 1000 Snapshot observations and 500 Pure-Parallel observations may be allocated. Additionally, up to 1500 orbits may be awarded for Multi-Cycle Treasury programs. Abstracts of previously accepted programs can be found on the HST proposal catalogs webpage.

This document establishes the goals, requirements, and policies for General Observer (GO) and Archival Research (AR) programs in Cycle 32. The table of contents for the web version of this document is on the right side of the page, and links there can take you to any page from any other page (click the arrow to expand the entire table of contents under "Hubble Space Telescope Call for Proposals for Cycle 32"). The links at the top of each page correspond to sections within that given page.

Proposing Calendar and Deadlines

Cycle 32 Dates: October 1, 2024 – September 30, 2025

Cycle 32 Phase I proposal deadline: Tuesday March 26, 2024 at 8:00pm EDT

Cycle 32 Peer Review meeting: May 28 - June 5, 2024

Cycle 32 Phase II proposal deadline: Wednesday July 17, 2024

Cycle 32 Budget submission deadline: ~August 1, 2024 at 5:00pm EDT

Cycle 32 Mid-Cycle deadline: TBD

Notification of the outcome of the Phase I selection process will be sent to all proposers in mid-late June 2024.

What's New for Cycle 32

See HST New and Important Features.

Where to Get Help

Who's Responsible

The HST Call for Proposals and related materials for Cycle 32 were edited by Jamila Pegues. The Associate Director for Science, Neill Reid, and the Science Mission Office (SMO) at STScI are responsible for the oversight of the HST science program selection process. SMO members include Alessandra Aloisi (SMO Mission Head), Elena Sabbi (SMO Deputy Mission Head), Laura Watkins (SMO Deputy Mission Head), Claus Leitherer (Hubble Science Policies Lead), Katey Alatalo, Christine Chen, Andrew Fruchter, Amaya Moro-Martin, Jamila Pegues, Linda Smith, and Technical Managers Brett Blacker and Aleksandra Hamanowicz.

Download the PDF

This PDF is provided as a courtesy, made available and updated when feasible. The online documentation is the authority, and will be updated with the latest information.

Next: HST New and Important Features