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 16, 2026 at 8:00pm EDT.  

Please submit well before the deadline whenever possible, to avoid possible last-minute hardware or overloading problems, or network delays/outages. Proposals can be resubmitted multiple times; the latest version submitted before the deadline will be the version that is evaluated. In exceptional cases where there are unforeseen and extenuating circumstances beyond a proposer's control, proposers may request a moderate extension to the deadline via the HST Help Desk. 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. The APT portal will close and will not accept any submissions or re-submissions after Thursday, April 16, 2026 at 8:00pm EDT.


Questions about policies and technical issues should be addressed to the HST Help Desk 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 34 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:


The PDF attachment:

Proposals which violate any of these policies will be subject to disqualification in the review process.


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. This can happen if you use the generated PDF Preview file as your Proposal PDF Attachment.


Page limits are now discussed under HST Preparation of the PDF Attachment


Use of Generative Artificial Intelligence (GAI) Technology

Proposers are not prohibited from the use of Generative Artificial Intelligence (GAI) tools, such as ChatGPT. However, following NASA policy, the proposal must acknowledge content that is not the creative product of the proposal team.

Thus, any material contained in the proposal that is derived from GAI must be described and cited, e.g., the name of the program, version number, the date and time, and a short statement on how the GAI was used.

This information must be included with the References and does not count against the page limits. Failure to disclose the use of GAI will result in disqualification.

Proposers are reminded that using GAI tools will place that text in the public domain. Reviewers are forbidden from uploading proposal content or review materials to GAI tools, since this violates the confidentiality of the review process.


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 APT's Proposal Information form, select the file on your local disk with your Proposal PDF Attachment.

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). When selecting your PDF attachment, take care to not select a previously made preview of the entire PDF, as that will put investigator information into your proposal and violate the requirements for Dual Anonymous Peer 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