HST Guidelines and Checklist for Phase I Proposal Preparation

This page describes the formatting of Phase I proposals, the page limits for various types of proposals, and provides a checklist for proposers to consult when developing their observing proposals.

General Guidelines

Deadline

The deadline for proposal submission is Thursday, April 10, 2025 at 8:00pm EDT. As part of the proposal submission process, proposers should submit a Team Expertise and Background section, following the instructions in HST Filling Out the APT Phase I Proposal Form.  We strongly recommend that proposers start preparing their proposals early in order to give themselves enough time to learn APT. Cycle 33 will use APT 2024.7.1, with an anticipated release of no later than February 10, 2025.

Proposals can be resubmitted up until the deadline.  Proposers are encouraged to submit well before the deadline whenever possible, to avoid possible last-minute hardware or overloading problems, or network delays/outages.

In exceptional cases where there are extenuating circumstances beyond a proposer’s control, proposers may request a moderate extension to the deadline via the HST Helpdesk. Extensions must be requested before the deadline with appropriate justification. In these cases, if possible, it will be helpful to submit a preliminary proposal before the deadline including the proposal title, investigators, number of orbits requested, and requested instruments. Late proposals will not be considered.

Questions about policies and technical issues should be addressed to the STScI Helpdesk well before the deadline. While we attempt to answer all questions as rapidly as possible, we cannot guarantee a speedy response in the last week before the deadline.

Phase I Proposal Format

Cycle 33 Proposals must be submitted electronically. The Java-based APT (the Astronomer's Proposal Tool) is the interface for all Phase I and Phase II proposal submissions for HST.

A Phase I proposal consists of two parts:

Both are submitted to STScI directly from within APT. 

You are responsible for ensuring that your PDF upload does not include extraneous material (such as extra cover pages, team expertise statements, and backup material). Extraneous material that causes the proposal to exceed the page limits or violate requirements of Dual Anonymous Peer Review will lead to disqualification of the proposal without review.

Page Limits for PDF Attachment


There are page limits on the size of your PDF attachment. The table below outlines these limits for different proposal categories.  Following the recommendations of the Hubble Space Telescope Users Committee, page limits have been reduced substantially. The bulk of the PDF file should comprise the Scientific Justification and the Description of Observations (for GO programs) or Analysis Plan (for AR programs).


Page limits have changed

Page limits have changed from previous cycles, and in most cases are halved!

Note that one additional page available for the following sections, combined: Special Requirements, Justify Coordinated Parallel Observations, Justify Duplications and Justify Coordinated Observations with Other Facilities.

References still do not count toward page limits, and should be listed at the end of the proposal.


Table: Page Limits

Proposal Category1

Total Page Limit for PDF Attachment

Very Small GO

Small GO

Regular AR

Regular AR/Theory

Snapshot

4, plus 1 page combined for cases listed below*

Very Small GO-AR

Small GO-AR

5, plus 1 page combined for cases listed below*

Medium GO

Medium GO-AR

5, plus 1 page combined for cases listed below*

Large GO

Large GO-AR

Treasury GO

6, plus 1 page combined for cases listed below*

1For Calibration GO, Joint HST-Chandra, Joint HST/XMM-Newton, Joint HST-NOIRLab, Joint HST-TESS, and Joint HST-NRAO Proposals, users should determine whether their proposal is Very Small, Small, Medium or Large based on the HST orbit request, and use the appropriate page limits. DD proposals are also required to follow these guidelines.

*One total additional page is available in all the above cases for the following sections combined: Special Requirements, Justify Duplications, and Coordinated Observations (including Joint Programs).

In relation to these page limits, note the following:

  • Proposals that exceed the page limits will be penalized in the review process; and risk being disqualified from the review in extreme cases.
  • There are no limits on the numbers of figures and tables in the PDF attachment, and they may be interspersed in the text. However, the total page limit must be observed.
  • References should be listed at the end of the proposal and do not count against the page limits. There are no restrictions on how references should be formatted.
  • Your PDF attachment must be prepared with a font size of 12pt. Do not change the format of any of the templates provided by STScI.
  • All proposals must include a Scientific Justification. GO proposals must also include a Description of Observations. AR proposals must include an Analysis Plan; Analysis Plans for GO-AR proposals are optional. Other headings may be deleted if they are not relevant. See our template files for further details.
  • While there are no specific page limits on the scientific justification, the strongest proposals will have a balance between scientific justification and the other required sections (such as the Description of Observations or the Analysis Plan) so that reviewers can accurately assess the merits and feasibility of a proposal using the selection criteria.

Proposal Preparation Checklist


Table: Proposal Preparation Checklist 

Step

Procedure

1) Review the Phase I Roadmap

The HST Phase I Proposal Roadmap is a high level step-by-step guide to writing a Phase I proposal. It includes links to various documents and training videos.

2) Install APT

Go to the APT webpage. Follow the instructions there to download and install the latest version of APT onto your machine. You can also ask your system administrator to do an institution-wide installation.

3) Fill out the APT Phase I form

Use APT to fill out the Phase I form. Information on the use of APT, including movie tutorials, is available on the APT webpage. A description of which items are requested as well as guidelines for answers are presented in HST Filling Out the APT Phase I Proposal Form. Proposers can save work in progress, so APT submission can be completed over several sessions.

4) Download a template file for the creation of your PDF attachment

Download one of the templates to create your PDF attachment. There are separate template files for GO and for AR/Theory Proposals. Template files are available in LaTeX and Microsoft Word.

5) Edit the template

Edit the template using your favorite word-processing application. A description of which issues need to be discussed, and guidelines for how to discuss them, are presented in HST Preparation of the PDF Attachment.

6) Create the PDF attachment.

Transform your edited template into a PDF file. Any figures in your proposal must be included into this PDF file. We will provide the reviewers with the electronic PDF files so that figures can be viewed in color. However there is no guarantee that the reviewers will view the files electronically, so please make sure your figures are useful when printed using grey scales.

7) Anonymize the PDF attachmentEnsure that your PDF attachment containing your Scientific and Technical sections are sufficiently anonymized, in accordance with the HST Anonymous Proposal Reviews guidelines.

8) Add the PDF filename path to the APT form

In your APT form, list in the appropriate box the path that points to the PDF attachment file on your local disk.

9) Review your proposal

In APT, click on ‘PDF Preview’ to get a preview of all the final information in your proposal. What you will see is the fully synthesized proposal we keep on record at STScI. The reviewers will see essentially the same, without the list of investigators and without the Team Expertise and Background sections (see HST Proposal Selection Procedures). If you are not satisfied at this stage, make any necessary changes.

You are responsible for ensuring that your PDF upload does not include extraneous material (such as extra cover pages, team expertise statements, and backup material). Extraneous material that causes the proposal to exceed the page limits or violate requirements of Dual Anonymous Peer Review will lead to disqualification of the proposal without review.

10) Institutional Endorsement

STScI does not require institutional endorsement of GO/AR Proposals in Phase I. However, some institutions do require such endorsement of all submitted proposals. It is the responsibility of each PI to follow all applicable institutional policies concerning the submission of proposals.

11) Submit your proposal 

In APT, use the Submission tool to submit your proposal to STScI. All parts are sent together (i.e., both the APT form information and the PDF attachment).

12) Receive an STScI acknowledgment of your submission

Verification of a successful submission will appear in the Submission Log on the Submission Screen in APT within about a minute. Also, the PI and all Co-Is will receive an automatic email acknowledgment that the merged PDF submission was received successfully. After the Phase I deadline has passed, and all submissions are in their final form, you will receive final notification that your submission has been successfully processed; this email will mark the completion of the submission. You should expect to receive the final notification email within 5 business days of the deadline. If there are any problems associated with your PDF attachment, you will be contacted by email.


Next: HST Filling Out the APT Phase I Proposal Form