The Defense Advanced Research Projects Agency (DARPA) Strategic Technology Office (STO) seeks information, data, analysis, or other results on capabilities that enable the operation and survival of electronics and energetic materials in extreme environments. A classified addendum at the Collateral SECRET level will be provided to potential responders who put in a request to DARPA-SN-25-10@darpa.mil. A formal request for the classified addendum may be submitted by filling out the DARPA-SN-25-10 CLASSIFIED ADDENDUM REQUEST FORM (Appendix 1) and by emailing the Request Form to DARPA-SN-25-10@darpa.mil with the subject line “Request DARPA-SN-25-10”. Submitters are required to submit this request no later than 4:00 p.m. (Eastern) on December 6, 2024, to allow adequate time to deliver the material. Requests submitted after this date will be disregarded. The DARPA-SN-25-10 CLASSIFIED ADDENDUM REQUEST FORM is the only method of request that will be accepted. All requestors will receive a confirmation email with either a delivery tracking number or email confirmation, depending on the delivery method. Proof of facility clearance level must be validated by the program security point of contact before any classified documentation on the RFI is sent to the submitter. Classified responses are required to be returned no later than 4:00 p.m. (Eastern) on December 17, 2024.