Cathode Advancements in Science and Technology for Oxygen Resistance (CASTOR)

SOL #: DARPA-PA-25-07-03Solicitation

Overview

Buyer

DEPT OF DEFENSE
Defense Advanced Research Projects Agency (Darpa)
DEF ADVANCED RESEARCH PROJECTS AGCY
ARLINGTON, VA, 222032114, United States

Place of Performance

Place of performance not available

NAICS

Research and Development in the Physical (541715)

PSC

National Defense R&D Services; Department Of Defense Military; Applied Research (AC12)

Set Aside

No set aside specified

Timeline

1
Posted
Mar 13, 2026
2
Last Updated
Apr 9, 2026
3
Submission Deadline
Apr 27, 2026, 4:00 PM

Qualification Details

Fit reasons
  • NAICS alignment with historical contract wins in similar service areas.
  • Scope strongly matches core technical capabilities and delivery model.
Risks
  • Past performance thresholds may require one additional teaming partner.
  • Potential clarification needed on staffing minimums before bid/no-bid.
Next steps

Validate eligibility requirements, assign capture owner, and schedule partner outreach to confirm teaming strategy before submission planning.

Quick Summary

The Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) has issued a Disruption Opportunity (DO) titled "Cathode Advancements in Science and Technology for Oxygen Resistance (CASTOR)". This initiative seeks innovative basic or applied research for efficient, high-performance, long-lived oxygen-compatible cathodes for use in air-breathing very low earth orbit (VLEO) electric propulsion (EP) systems. Awards will be made as Other Transactions (OT) for Prototype projects, with a total value limited to $900,000. Proposals are due by April 27, 2026, at 4:00 p.m. ET.

Purpose and Scope

DARPA aims to develop cathodes capable of operating with either air or water as the primary working fluid, matching the performance of current noble gas-based EP systems. This will extend the operational capabilities of EP systems in VLEO environments.

Key Requirements / Deliverables

  • Develop cathodes supporting EP thrusters operating on air or water for 1,000 hours or more.
  • Achieve performance comparable to current noble gas-based cathodes in oxygenic environments (capacity, efficiency, lifetime).
  • Explore multiple electron emission mechanisms (e.g., thermionic, field emission, photoemission, secondary electron emission, RF plasma).
  • Deliver a cathode test article to the Government at the end of Phase 2.

Contract Details

  • Type: Other Transaction (OT) for Prototype project, issued under DARPA-PA-25-07.
  • Structure: Two-phase, 21-month program.
    • Phase 1 (Feasibility Study): 9 months, limited to $350,000.
    • Phase 2 (Proof of Concept): 12 months, limited to $550,000 (option).
  • Total Award Value: Limited to $900,000 (includes Government funding and performer cost share).
  • Anticipated Start: June 29, 2026.
  • Product Service Code: AC12 (National Defense R&D Services; Applied Research).

Submission & Evaluation

  • Proposals Due: April 27, 2026, 4:00 p.m. Eastern Time.
  • Submission Method: Electronic via DARPA's Broad Agency Announcement (BAA) Portal.
  • Content: Proposals must comply with content and format instructions in Section 5 of DARPA-PA-25-07 and use provided templates, including a Streamlined Cost Buildup Workbook. Amendment 1 clarified the complete list of required attachments.
  • Evaluation: Based on criteria outlined in Section 6 of DARPA-PA-25-07.
  • Milestones: Kickoff meetings, conceptual design reviews, quarterly reviews, and final reviews for each phase.

Eligibility / Set-Aside

  • Set-Aside: None specified.
  • Eligibility: Federally Funded Research and Development Centers (FFRDCs) and Government Entities may be eligible under specific conditions. University Affiliated Research Centers (UARCs) are eligible as performers only in fields where they do not serve in an advisory role, requiring an OCI mitigation plan.

Important Notes

  • Performers must conduct the majority of cathode testing in their own facilities; supplemental testing at the U.S. Naval Research Laboratory (NRL) may be leveraged.
  • A Government independent verification and validation (IV&V) team will assist the program.
  • Proposers must review the model OT for Prototype agreement prior to submission.
  • Contact: BAA Coordinator at CASTOR@darpa.mil.

People

Points of Contact

BAA CoordinatorPRIMARY

Files

Files

Download
Download
Download
Download
View

Versions

Version 2Viewing
Solicitation
Posted: Apr 9, 2026
Version 1
Solicitation
Posted: Mar 13, 2026
View
Cathode Advancements in Science and Technology for Oxygen Resistance (CASTOR) | GovScope