DARPA's Tactical Technology Office (TTO) has issued a Request for Information (RFI) DARPA-SN-26-21, seeking insights into on-orbit satellite nuclear power concepts. The RFI focuses on producible and cost-effective nuclear reactors, not bespoke designs. Responses are due by February 6, 2026, at 4:00 p.m. ET. DARPA, in collaboration with the Department of Energy (DOE), will also host a workshop on March 31 and April 1, 2026, in Arlington, VA, to foster understanding, collaboration, and identify key technology risks in this field. The RFI requests information on use cases, reactor design, power conversion, technical challenges in design, testing, integration, and innovative approaches for development and qualification, including initial technology demonstration objectives. Submissions should be non-proprietary white papers, not exceeding eight pages, and emailed to DARPA-SN-26-21@darpa.mil. Selected respondents for workshop attendance will be notified by March 2, 2026. This RFI is for information and program planning only and does not constitute a solicitation for proposals.

This document, "Attachment 1 – Security Information," outlines security requirements for submitting white papers to the DARPA TACTICAL TECHNOLOGY OFFICE (TTO) for the "On-orbit Nuclear Power Concepts Workshop." It details protocols for both Controlled Unclassified Information (CUI) and classified submissions. For CUI, applicants must ensure their information systems comply with NIST SP 800-171 and DoDI 8582.01, and submissions must be marked according to DoDI 5200.48. For classified submissions, applicants need appropriate facility clearance and must mitigate Foreign Ownership Control and Influence (FOCI) issues. Classified materials must be marked based on a Security Classification Guide (SCG) provided to DARPA 20 days prior to any event. The document also specifies procedures for submitting Confidential, Secret, and Top Secret information, including electronic, hand-carried, and mailed options, and how to handle submissions containing both classified and unclassified content.