2027 NASA Hubble Fellowship Program (NHFP): Postdoctoral Fellowship in Astrophysics for International Scientists

The 2027 NASA Hubble Fellowship Program (NHFP) is inviting applications from qualified postdoctoral scientists interested in conducting independent research that contributes to the field of NASA Astrophysics.

Administered by the Space Telescope Science Institute (STScI) on behalf of the NASA Astrophysics Division, the program supports researchers working in astronomy, physics, and related disciplines. Successful applicants will join one of three fellowship tracks — Einstein, Hubble, or Sagan Fellow — depending on their area of research.

The fellowship provides an opportunity for early-career scientists to pursue independent theoretical, observational, and/or instrumental research at a U.S. host institution of their choice, subject to the program’s host-institution rules.

Applications for the 2027 fellowship cycle opened on September 8, 2026, with applications due on October 28, 2026.

About the NASA Hubble Fellowship Program

The NASA Hubble Fellowship Program is a postdoctoral research fellowship program administered for NASA by the Space Telescope Science Institute (STScI).

The program is designed to support postdoctoral scientists conducting independent research that contributes to NASA’s astrophysics mission.

Research supported through the program can be:

• Theoretical
• Observational
• Instrumental
• Or a combination of these approaches

The program gives early-career scientists an opportunity to develop an independent research program while working at a U.S. host institution.

Depending on the research area, successful fellows will be designated as:

• NASA Einstein Fellows
• NASA Hubble Fellows
• NASA Sagan Fellows

These fellowship designations correspond to different areas of astrophysical research within the broader NHFP program.

2027 NASA Hubble Fellowship Program at a Glance

Detail	Information
Program	NASA Hubble Fellowship Program (NHFP)
Fellowship cycle	2027
Opportunity type	Postdoctoral research fellowship
Research field	Astronomy, physics and related disciplines
Research focus	NASA Astrophysics
Fellowship duration	Up to 3 years
Initial appointment	1 year
Renewals	Two annual renewals
Number of fellowships	Up to 24 anticipated
Host location	U.S. host institution of the fellow’s choice
Nationality	Applicants of any nationality
Application opening	September 8, 2026
Application deadline	October 28, 2026
Application deadline time	7:00 PM EDT / 4:00 PM PDT
Reference-letter deadline	November 4, 2026
Expected offers	Early February 2027
Expected start date	On or about September 1, 2027
Application source	STScI NHFP Announcement of Opportunity

Who Can Apply for the 2027 NHFP?

The NASA Hubble Fellowship Program is open to applicants from all nationalities.

To be eligible, applicants must have completed or be expected to complete all requirements for their doctoral degree on or after January 1, 2023.

The doctorate must be in:

• Astronomy
• Physics
• Or a related discipline

The program is therefore specifically designed for researchers at the postdoctoral stage who have recently completed, or are about to complete, their doctoral training.

Research Areas

NHFP fellows are expected to conduct independent research that contributes to NASA Astrophysics.

The program allows research to be theoretical, observational, instrumental, or a combination of these approaches.

This broad research structure means that applicants working across different areas of astrophysics may be able to develop fellowship proposals aligned with their specific scientific interests and expertise.

The fellowship designation awarded to a successful applicant — Einstein, Hubble, or Sagan — will depend on the applicant’s research area.

Fellowship Duration

The NASA Hubble Fellowship can last for up to three years.

The fellowship is structured as:

1. Initial one-year appointment
2. First annual renewal
3. Second annual renewal

The two renewals are contingent on:

• Satisfactory performance
• Availability of NASA funding

Therefore, although the program offers the possibility of a three-year fellowship, continuation beyond the initial appointment is not described as unconditional.

U.S. Host Institution

NHFP Fellowships are tenable at a U.S. host institution of the fellow’s choice.

However, the program places limits on the number of new fellows that can be hosted by an individual institution.

The stated policy allows:

• A maximum of two new fellows per host institution per year
• One new fellow for institutions that hosted two new fellows during the previous year

Host institutions must also have verified compliance with the NHFP employment policy.

Applicants should therefore review the official list of verified host institutions before finalizing their host-institution plans.

Number of Fellowships Available

For the 2027 cycle, the program anticipates offering up to 24 NHFP Fellowships.

The actual number of fellowships offered can therefore be up to 24 for the cycle.

Because this is a competitive postdoctoral research program, applicants should carefully follow the official application instructions and prepare their materials according to the requirements in the Announcement of Opportunity.

Organizations Administering the NHFP

The program is administered for NASA by the Space Telescope Science Institute (STScI).

STScI administers the program in collaboration with:

• The Jet Propulsion Laboratory (JPL)
• NASA Exoplanet Science Institute (NExScI) at the California Institute of Technology
• The Chandra X-ray Center at the Smithsonian Astrophysical Observatory

This collaborative structure connects the fellowship with several major institutions involved in astrophysical research.

What Fellows Will Do

The central purpose of the NHFP is to support postdoctoral scientists conducting independent research.

Research may involve theoretical investigations, observations, instrumentation, or combinations of these approaches.

The independent nature of the fellowship is particularly important because it allows postdoctoral researchers to develop their own research programs and contribute to the broader scientific objectives of NASA Astrophysics.

Applicants should therefore ensure that their proposed research clearly demonstrates its relevance to astrophysics and its contribution to the scientific objectives of the program.

Application Timeline for the 2027 NHFP

Applicants should pay close attention to two different deadlines: the main application deadline and the reference-letter deadline.

September 8, 2026 — Applications Open

The application submission page opens on September 8, 2026.

Applicants can begin preparing and submitting their application materials from this date.

October 28, 2026 — Main Application Deadline

Applications are due on:

Wednesday, October 28, 2026

The exact deadline is:

7:00 PM EDT / 4:00 PM PDT

Applicants should make sure their application is submitted before the stated deadline.

November 4, 2026 — Reference Letters Due

Reference letters are due one week after the main application deadline:

Wednesday, November 4, 2026

Applicants should contact their referees well in advance and make sure they understand the separate deadline for submitting their letters.

An important instruction in the announcement is that letter writers will not receive an automated email with a link to upload their letters.

Reference letters must be uploaded as PDF files through the designated letter submission form.

Early February 2027 — Fellowship Offers

The program expects fellowship offers to be made in early February 2027.

September 1, 2027 — Expected Fellowship Start

New appointments are expected to begin on or around:

September 1, 2027

How to Apply

Applicants should carefully follow the instructions provided in the official NHFP Announcement of Opportunity.

The announcement includes detailed information about:

• Program policies
• Eligibility
• Application requirements
• Application instructions
• Host-institution policies
• Other fellowship requirements

The program specifically instructs applicants to use the designated official application information and submission system.

Applicants are also encouraged to review the Frequently Asked Questions available through the main NHFP page before submitting their application.

Important Application Instructions

One of the most important instructions is that applicants should use only the official STScI NHFP application information when applying.

The program provides the application submission page through the NHFP system, while the Announcement of Opportunity contains the detailed instructions applicants need to follow.

Applicants should not rely on unofficial websites or third-party application links when submitting their materials.

Reference Letters

Reference letters are an important part of the NHFP application process.

Applicants should communicate with their chosen referees early enough to allow them to prepare and upload their letters before the separate reference-letter deadline.

The reference-letter deadline is:

November 4, 2026

The announcement specifically notes that referees will not receive an automated email containing an upload link.

Applicants should therefore make sure their letter writers are aware of the submission procedure and deadline.

Letters must be submitted as PDF files using the designated letter submission form.

Frequently Asked Questions

The NHFP encourages applicants to examine the program’s Frequently Asked Questions before submitting an application.

This can help applicants understand program policies and clarify requirements that may not be obvious from the basic fellowship announcement.

Because the fellowship has specific policies concerning eligibility, host institutions, application submission, and references, prospective applicants should review the official program materials rather than relying solely on summaries.

International Eligibility

One notable feature of the NASA Hubble Fellowship Program is its international eligibility.

The fellowship is open to English-speaking citizens of all nations.

This means that the program is not limited to U.S. citizens.

Applicants from different countries can therefore apply, provided they satisfy the academic and doctoral-degree eligibility requirements and meet the other requirements specified in the official Announcement of Opportunity.

The fellowship itself is tenable at a U.S. host institution.

Equal Opportunity Statement

The program states that all applicants will receive consideration without regard to:

• Race
• Creed
• Color
• Age
• Sex
• Sexual orientation
• National origin

The announcement also identifies the employer as an Equal Opportunity Employer and provides information concerning protected veterans and individuals with disabilities.

Click HERE to read more.

Why the NHFP Can Be Significant for Early-Career Researchers

A postdoctoral fellowship can provide an important transition between doctoral research and a longer-term independent research career.

The NHFP specifically emphasizes independent research, making the program relevant to scientists who want to develop their own research direction in astrophysics.

The potential three-year duration can also provide researchers with an extended period to pursue a substantial research program.

In addition, the opportunity to work at a U.S. host institution of the fellow’s choice, subject to NHFP policies, provides flexibility in selecting a research environment that aligns with the fellow’s scientific interests.

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Conclusion

The 2027 NASA Hubble Fellowship Program (NHFP) offers a major postdoctoral research opportunity for scientists working in astronomy, physics, and related disciplines.

Administered by the Space Telescope Science Institute on behalf of NASA’s Astrophysics Division, the program supports independent theoretical, observational, and instrumental research that contributes to NASA Astrophysics.

The fellowship can run for up to three years, beginning with a one-year appointment followed by two possible annual renewals subject to satisfactory performance and NASA funding availability. Up to 24 fellowships are anticipated for the 2027 cycle.

The program is open to English-speaking citizens of all nations who have completed or will complete their doctoral-degree requirements on or after January 1, 2023, in astronomy, physics, or a related discipline.

Applications opened on September 8, 2026, and the main application deadline is Wednesday, October 28, 2026, at 7:00 PM EDT / 4:00 PM PDT. Reference letters have a separate deadline of November 4, 2026.

Researchers interested in applying should carefully review the official NHFP Announcement of Opportunity and Frequently Asked Questions and ensure that both their application and reference-letter arrangements comply with the program’s requirements.

Click HERE for more fellowship opportunities.