NASA ESI26-ISRU Grant 2026: Up to $1.5 Million for Lunar Water Purification Research

NASA ESI26-ISRU Grant 2026: Up to $1.5 Million for Lunar Water Purification Research

NASA’s Early Stage Innovations for In Situ Resource Utilization (ESI26-ISRU) is a narrow, research-intensive grant opportunity for U.S. colleges and universities. The call asks for an end-to-end, regeneratable system that purifies water extracted from lunar regolith. It is not a general space-technology program and it is not a business accelerator: a proposal must directly address NASA’s stated Lunar In Situ Resource Utilization Water Purification topic.

The opportunity is part of NASA’s FY 2026 Space Technology Research, Development, Demonstration, and Infusion (SpaceTech REDDI) announcement. NASA anticipates about three grant awards, each lasting up to three years and capped at $1.5 million total, with no more than $500,000 requested in a single year. The first gate is a mandatory preliminary proposal (MPP), due August 13, 2026, at 5:00 p.m. Eastern Time. NASA expects to invite a subset of MPP applicants to submit full proposals, currently targeted for December 16, 2026. An MPP is therefore the actual application deadline for a team that has not yet entered the competition.

This guide translates the official call into a practical planning document. It does not replace the NASA solicitation page, the Appendix B7 announcement, or the related NSPIRES documents. Those sources control if anything changes.

Key details at a glance

What NASA is offering—and what it is not

ESI26-ISRU supports early-stage, high-risk research that could materially improve future civil-space systems. The solicitation describes the expected starting maturity as typically Technology Readiness Level (TRL) 2 or 3 and the expected endpoint as typically TRL 3 or 4. In plain terms, NASA is looking for a defensible research concept and proof-of-concept development, not a finished flight system and not a modest refinement of a mature terrestrial product.

The distinctive technical problem is lunar water purification. NASA wants an end-to-end regeneratable system that can take simulated lunar water containing regolith simulant and a subset of volatiles observed by the LCROSS mission, then produce water meeting the potable-water standard named in the solicitation. At least ammonia or methanol must be among the included contaminants. The system must not depend on replacing components or materials to purify water or manage removed contaminants for two years. The proof-of-concept itself does not have to be fully automated, but the proposal must explain how a final system could meet that two-year requirement.

That precision is useful for deciding whether to invest proposal effort. A project on lunar extraction alone, generic filtration, broad Mars-water concepts, a non-space environmental application, or a survey of current research is not a close match. NASA says proposals must be primarily responsive to civil-space needs, and it specifically excludes literature searches, survey activities, and incremental state-of-the-art improvements. It also says nonresponsive proposals will not proceed to peer review.

Who should consider applying

The lead applicant must be a U.S. IHE. The PI must be a tenured faculty member or an untenured faculty member on the tenure track at that institution. There is no stated institutional cap on the number of applications a U.S. IHE may submit, but an individual may participate in no more than two proposals total, whether as PI, Co-PI, or Co-Investigator. Exceeding that limit can make all of the person’s submissions noncompliant, so a department should coordinate early rather than discovering overlap during routing.

The strongest fit is likely a research team that can credibly connect chemical or environmental engineering, separations, materials, electrochemistry, systems modeling, and spacecraft-life-support or ISRU expertise. A collaboration can help, but it does not relax the basic requirements. At least 50% of the proposed budget must go to the proposing IHE and at least 70% must go to U.S. IHEs. Other IHEs, industry, and nonprofit entities may team under the call’s constraints. Other federal agencies and non-NASA federally funded research and development centers may collaborate but cannot receive award funds. NASA Centers and JPL may not collaborate on submitted proposals or appear as team members.

International collaborators are addressed through the umbrella SpaceTech REDDI announcement. If a team contemplates foreign participation, export-control issues, or a non-U.S. research expense, it should use the controlling NASA guidance and institutional research office—not informal assumptions—to determine what is allowed. The Appendix expressly says that award funds may not support research performed by non-U.S. organizations, although U.S. recipients may directly purchase certain non-U.S. supplies or services that do not constitute research.

The technical scope: build a system, not a disconnected component

NASA’s desired result is not merely a promising membrane, sorbent, catalyst, or filter coupon. The proposed effort must design and test a joined-up purification system. Both modeling and hardware are mandatory research areas:

• Modeling: computational tools that guide purification-system design.
• Hardware: necessary system or subsystem proof-of-concept demonstrations that validate the design assumptions and modeling.

The application must discuss scale-up to a flight-forward system while minimizing size, weight, and power (often abbreviated SWAP). The cited target scale-up is on the order of 10 metric tons of water per year. Applicants must justify their contaminant mixture, identify the regolith simulant and LCROSS-observed volatiles they will study, describe how they will integrate and test the system, and state expected output-contaminant levels. NASA encourages, but does not require, work that converts potable water to ultrapure deionized water with minimal consumables and approaches a throughput on the order of 3 kilograms per hour. It also encourages applicants to consider lunar-environment impacts and, where relevant, capture of contaminants for other uses.

Treat these as design constraints rather than phrases to repeat. A useful internal test is whether the proposal explains the system boundary, material and contaminant path, regeneration mechanism, measurable output quality, and why the evidence generated will reduce a real flight-forward uncertainty. If the components work only because consumables are periodically swapped out, the central requirement has not been met.

How the two-step application works

The first-stage MPP is mandatory. Only applicants that submit an MPP and receive an invitation may submit a full proposal. The full proposal must concern the same technology and technological approach as the MPP; material changes to the approach can make it noncompliant. NASA expects to notify applicants of invitation status around October 9, 2026. The listed full-proposal deadline is a target and may move if MPP review is delayed.

For the MPP, the NSPIRES cover page is generated from the online information. Applicants upload two anonymized documents: an Anonymized Proposal Summary Chart and an Anonymized Proposal Document. The chart is one landscape 8.5-by-11-inch page, uses at least 10-point font, and includes the title, a representative graphic with caption, objectives, comparison with the state of the art, innovation, starting and projected ending TRL, approach, and impact. NASA intends to make that chart public after selections, so it may not contain proprietary or sensitive information.

The MPP technical plan has a three-page limit, including figures, tables, and subsections. It must address relevance, responsiveness to the specific topic, state of the art and innovation, technical approach, methodology, and starting and ending TRLs. References may be included as needed. The short format is not a reason to omit experimental logic; it is a reason to decide which causal claims, metrics, and validation steps carry the argument.

If invited, the full proposal retains an anonymized summary chart and anonymized proposal document, then adds a non-anonymized Expertise and Resources document. The full stage also requires a one-page anonymized data management plan and detailed budget material. NASA’s official Appendix and DAPR guidelines provide the complete document list and page limits; use the live documents rather than an old internal template.

Prepare for dual-anonymous review from day one

Both stages use Dual-Anonymous Peer Review (DAPR). In the anonymized documents, do not identify the team, institution, laboratory, or organization. Team members and organizations should be described by role or generic designation, such as “experimentalist,” “Co-I 1,” or “Org 1.” The call separately requires the proposal to avoid biographical information, statements about team members’ years of experience, and institution-identifying details in the anonymized technical material.

This can be more difficult than it sounds. Self-citations are not automatically forbidden, but authors must avoid signaling that a cited author is the PI or a team member. The proposal chart must likewise be anonymous. A useful workflow is to create an anonymization check after the scientific draft is stable: examine filenames, document metadata, figure labels, acknowledgements, institutional test-bed references, internal project names, and citations that make authorship obvious. Have someone who did not write the proposal attempt to identify the team from the anonymized files.

NASA may reject egregious DAPR violations without review, and it may redact material for lesser violations. Anonymity is therefore an administrative requirement with real consequences, not a formatting preference.

What reviewers will evaluate

At the MPP stage, NASA weights Relevance and Technical Approach equally at 50% each. Relevance includes direct responsiveness to the topic and a convincing state-of-the-art comparison with goals or metrics that substantiate the innovation claim. Technical Approach includes whether the methods are sound, logical, and feasible, as well as whether the starting and projected TRLs are appropriate and justified.

At the full-proposal stage, Relevance and Technical Approach each account for 40%, while Management Approach, Data Management Plan, and Proposal Cost together account for 20%. Full-proposal reviewers consider whether the technology could improve civil-space system performance, weight, cost, reliability, operational simplicity, or related measures; whether there is a realistic next step beyond the award; whether risks and mitigations are recognized; whether milestones and success criteria are clear; and whether the schedule and budget are credible.

This points to a straightforward writing discipline: state the performance problem first, identify the state-of-the-art limitation, define a testable advance, and connect every task to a milestone or decision. Do not rely on the team’s reputation to fill technical gaps. The technical panel initially evaluates the anonymized material without considering proposer qualifications. For a high-scoring subset, it later checks the non-anonymized expertise-and-resources document for clear capability to execute the work; unusually strong credentials cannot upgrade an otherwise weaker technical proposal.

A practical preparation plan before August 13

Start by deciding whether the proposed system genuinely satisfies the non-consumable, end-to-end condition. Then build one concise evidence package that can feed the MPP:

1. Define the lunar-water input mixture, including regolith simulant, at least ammonia or methanol, and the reason those contaminants represent the proposed test.
2. Draw the system boundary and identify what is regenerated, what is rejected or captured, how output quality is measured, and where model predictions will be tested in hardware.
3. Set a starting TRL, end TRL, and a small number of quantitative milestones. Make the claimed advance comparable with the selected state of the art.
4. Confirm the lead IHE, tenure or tenure-track status of the PI, all proposed personnel counts, and budget-allocation constraints before drafting collaboration language.
5. Register every participating organization and team member in NSPIRES. NASA says all participating organizations, including collaborator organizations, must be registered.
6. Create the anonymized chart and technical plan from the official templates, then send the record to the institutional grants office early enough for the AOR to submit.

The final submission is not complete because a PI has uploaded files. The MPP must be submitted in full by the submitting institution’s AOR through NSPIRES. NASA’s FAQ says the PI is responsible for confirming the proposal appears under “Submitted,” not merely “Unsubmitted,” before the deadline.

Common mistakes to avoid

The most avoidable error is proposing a related technology without showing it is a complete lunar-water purification system. A promising unit operation can be part of the research, but the proposal must show how it supports the required end-to-end demonstration and flight-forward regeneration concept.

Other frequent preventable problems follow directly from the call:

• Treating the full-proposal date as the first deadline and missing the required MPP.
• Disclosing the university, laboratory, investigator history, or otherwise identifying information in the anonymized documents.
• Including material changes between the invited full proposal and the MPP technology approach.
• Building a budget that exceeds $500,000 in a year or $1.5 million total, or that fails the lead-IHE and U.S.-IHE allocation rules.
• Treating cost sharing as an advantage. NASA says it is neither required nor considered in evaluation.
• Assuming access to NASA facilities, NASA Centers, or JPL resources in the proposal. The Appendix says such access may not be assumed, and NASA/JPL commitment letters are not permitted.
• Sending a proposal by email or hard copy. Only NSPIRES submissions are accepted.

Timeline, contacts, and official links

As of July 29, 2026, the important live dates are August 13, 2026 at 5:00 p.m. Eastern for the MPP; approximately October 9, 2026 for invitation-status notifications; December 16, 2026 at 5:00 p.m. Eastern as the target invited-full-proposal deadline; and June 2027 as the target award date. Funding remains contingent on appropriations, satisfactory progress, and continued relevance to NASA goals.

For the live notice, templates, the DAPR guidelines, and current FAQs, start at the official NSPIRES solicitation summary. The program office contact named in the Appendix is Matthew Deans at [email protected]. NASA says technical questions may be incorporated into the public topic-specific FAQ and will be accepted through December 9, 2026; it also says it cannot advise whether an individual research idea is responsive. For NSPIRES technical support, use [email protected] or 202-479-9376 during the hours published on the solicitation page.

Frequently asked questions

Is this open to startups or independent inventors?

Not as lead applicants under this Appendix. Only U.S. institutions of higher education may submit. Industry and nonprofit participation may be possible as part of a compliant team, but the lead applicant, PI eligibility, and budget-allocation conditions still apply.

Can a team submit a full proposal without an MPP?

No. The MPP is mandatory, and NASA will accept a full proposal only from teams that submitted an MPP and were invited. The full proposal must retain the MPP’s technology and approach.

Is the maximum award guaranteed?

No. $1.5 million is a ceiling, not a promised amount. NASA anticipates approximately three awards, says it may make no awards or more than three, and makes multi-year continuation contingent on available funds, progress, and relevance.

Is a replaceable filter enough?

The solicitation requires a system that can purify water and manage removed contaminants for two years without replacement of components or materials. A replaceable item may be useful in an exploratory test, but an application must explain how the final system satisfies the regeneration condition.

Does NASA want only a computer model?

No. The call requires both computational modeling and hardware development and testing of proof-of-concept demonstrations. The model should inform system design and be connected to experimental validation.

Where should an applicant confirm last-minute requirements?

Use the live NSPIRES page and its attached Appendix, FAQ, technical FAQ, summary-chart template, and DAPR guidance. Those official materials can be updated and take precedence over this guide.