Hubble Space Telescope Call for Proposals for Cycle 29

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

  • April 2, 2021
    • Proposers are reminded that proposals will be assessed against the 3 primary criteria, with a separate grade given for each:
      • scientific merit within the field,
      • broader importance for astronomy & the strength of the data analysis plan (where applicable);
      • HST’s unique capabilities must also be required to achieve the scientific goals.
    • These three criteria are given equal weighting during the scoring that determines the initial ranking of proposals.
  • March 25, 2021
    • As always, proposers are encouraged to check the release notes for the HST ETC, and the known issues linked at the bottom of that page, when preparing their proposals.
  • January 21, 2021
    • Apple has recently released new Mac hardware based on Apple Silicon (M1). The APT team has discovered that the HST Orbit Planner and Visit Planner tools are not compatible with this new hardware. An upgrade is being investigated.

See also HST Cycle 29 New and Important Features.


We invite scientists to participate in Cycle 29 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 2700 orbits in this cycle, including 1400 orbits for Small Programs, 700 orbits for Medium Programs, and 600 for Large and Treasury Programs. An additional 1000 Snapshot observations and 500 Pure-Parallel observations may be allocated. 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 29. 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 29"). The links at the top of each page correspond to sections within that given page.

Proposing Calendar and Deadlines

Cycle 29 Dates: October 1, 2021 – September 30, 2022

Cycle 29 Phase I proposal deadline: April 9, 2021 at 8:00pm EDT

Cycle 29 Peer Review meeting: June 16-23, 2021

Cycle 29 Phase II proposal deadline: July 29, 2021

Cycle 29 Budget submission deadline: August 12, 2021 at 8:00pm EDT

Cycle 29 1st Mid-Cycle deadline: September 30, 2021

Cycle 29 2nd Mid-Cycle deadline: January 31, 2022

Notification of the outcome of the Phase I selection process will be sent to all proposers in early July 2021.

What's New for Cycle 29

See HST Cycle 29 New and Important Features

Where to Get Help

Who's Responsible

The HST Call for Proposals and related materials for Cycle 29 were edited by 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 Science Policies Group), Katey Alatalo, Christine Chen, Andrew Fruchter, Amaya Moro-Martin, Molly Peeples, Laura Watkins, and Technical Manager Brett Blacker.

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 Cycle 29 New and Important Features