# SAM #DARPA-SN-27-03 DARPA Cattle Run Proposers Day for Autonomous Cislunar Spacecraft **Buyer:** DEF ADVANCED RESEARCH PROJECTS AGCY **Posted:** October 22, 2026 **Respond By:** November 04, 2026 **Identifier:** DARPA-SN-27-03 **NAICS:** 336415, 336419, 541715 DARPA is inviting potential proposers to learn about its Cattle Run program for autonomous spacecraft and persistent cislunar access. - **Opportunity:** Proposers Day to explain the program, answer questions, and support teaming discussions. - **Program focus:** Develop autonomous spacecraft using renewable propulsion to enable persistent access to cislunar space. - **Phase 1:** Develop and launch a demonstrator below geosynchronous orbit within 18 months. The spacecraft has no required form factor and is expected to gather on-orbit data demonstrating propulsion performance, sufficient acceleration, accurate vehicle control, and autonomous navigation. - **Phase 2:** Develop multiple spacecraft and demonstrate persistent cislunar access. - **Event and contact:** DARPA Conference Center, Arlington, Virginia; BAA Coordinator, DARPA-SN-27-03@darpa.mil. - **Notice update:** Amendment 01 was added. The latest notice omits the program description previously included; the original PDF remains available, and the provided history does not state specific amendment terms. - **Commercial details:** No OEMs, vendors, specific products, quantities, contract value, or contract period are identified. ### Description PROPOSERS DAY:
DARPA is hosting a Proposers Day in support of DARPA-SN-27-03 Cattle Run program on Tuesday, November 10, 2026, at the DARPA Conference Center (675 North Randolph Street, Arlington, VA 22203) from 8:00am to 5:00pm EST. The purpose of this conference is to provide information on the Cattle Run program; promote additional discussion on this topic; address questions from potential proposers; and provide a forum for potential proposers to meet for teaming opportunities. [View original listing](https://sam.gov/opp/bf79b55fdfdb41d89733869966ba4fa9/view)