The Hubble Space Telescope Primer for Cycle 34
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 34 is a companion document to the Hubble Space Telescope Call for Proposals for Cycle 34. 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
- December 18, 2025:
- APT Released: APT version 2025.7.2 is now available. Any HST proposals started in earlier APT versions should now be edited and submitted in this version.
- January 16, 2026:
- Word templates updated: Make sure to use the most recent version of the PDF attachment templates. Using an older template could cause the proposal to be disqualified.
See also HST New and Important Features.
Proposing Calendar and Deadlines
Cycle 34 Phase I proposal deadline: Thursday, April 16, 2026 at 8:00pm EDT
Cycle 34 Peer Review: June 22 - July 1, 2026
Cycle 34 Phase II proposal deadline: anticipated August 13, 2026 at 5:00pm EDT
Cycle 34 Budget deadline: end-August 2026, for planning purposes only
Where to Get Help
Submit questions to the HST Help Desk at http://hsthelp.stsci.edu. See http://www.stsci.edu/hst/ for additional tools and resources.
Who's Responsible
The HST Call for Proposals and related materials for Cycle 34 were edited by Amy Jones. The Associate Director for Science, Mercedes López-Morales, and the Science Policy Division (SPD) at STScI are responsible for the oversight of the HST science program selection process. SPD members include Laura Watkins (SPD Head), Claus Leitherer (Hubble Science Policy Lead), Molly Peeples (Cross-Mission Policy Scientist), Daniel D'Orazio, Rebecca Levy, Joshua Lothringer, Amaya Moro-Martín, Nikolay Nikolov, Lou Strolger, and Technical Manager Aleksandra Hamanowicz. Neill Reid (Multi-Mission Project Scientist) participates in an advisory capacity.