HST Proposal Opportunities and Science Policies

Articles in this section comprise the traditional Call for Proposals.  These articles include information on observing and science policies, and details on the proposal submission process, including roadmaps.

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.

Current HST Proposal Opportunities


Release Notice: January 13, 2021

We are pleased to announce the Cycle 29 Call for Proposals for Hubble Space Telescope (HST) observations and funding for archival research programs.

Participation in this program is open to all categories of organizations, both domestic and foreign, including educational institutions, profit and nonprofit organizations, NASA Centers, and other Government agencies.

Cycle 29 will extend from  October 1, 2021 to September 30, 2022. We will accept proposals for the following instruments: ACS, COS, FGS, STIS, and WFC3.

We anticipate allocating up to 2700 orbits in this cycle. See Hubble Space Telescope Call for Proposals for Cycle 29 for further details.  

This solicitation for proposals will be open through April 9, 2021 at 8:00pm EDT. The Astronomer's Proposal Tool (APT), which is required for Phase I Proposal Submission, was made available for Cycle 29 Phase I use on December 18, 2020. Results of the selection will be announced by early July.

Questions can be addressed to the STScI HST Help Desk (https://hsthelp.stsci.edu or email help@stsci.edu).  We encourage the use of the new website where you can submit questions directly to the appropriate team of experts.

The Cycle 29 Call for Proposals

The Call for Proposals (CP) invites the astronomical community to propose for observing time on HST in a given cycle (nominally one year in duration). It summarizes the policies and procedures for proposing in that cycle of HST observing, including requests for research funding on archival HST data.  See Hubble Space Telescope Call for Proposals for Cycle 29 for more information.

The Hubble Space Telescope Primer for Cycle 29 provides an overview of the Hubble Space Telescope, with basic information about the telescope operations, instrument capabilities, and technical aspects of the proposal preparation process. 

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.

Science Justification Templates

Templates for HST Cycle 29 Proposal PDF attachments:

Note: the Word and LaTeX templates have intentionally different margins, to accommodate the same amount of text per page. See HST Cycle 29 Guidelines and Checklist for Phase I Proposal Preparation for information on page limits.

See HST Cycle 29 Preparation of the PDF Attachment for more information.

Download the PDF

Supporting Documents