The Advanced Research Projects Agency for Health (ARPA-H) Comprehensive Organ System Modeling in Outer Space (COSMOS) Initiative aims to definitively prove or disprove if exposure to microgravity in Low Earth Orbit (LEO) truly accelerates tissue aging across brain, cardiac, uterine, and kidney tissue types and across several adult age brackets. Provided Tissue Aging Rate in Space (TARIS) exceeds Tissue Aging Rate on Earth (TAROE) at a rate that exceeds the on Earth breakeven cost for new drug R&D, COSMOS will create a first-in-class platform for fully autonomous, high-throughput drug screening in LEO that would be more cost effective and faster than new drug R&D on Earth.

ARPA-H anticipates multiple Other Transaction awards resulting from this announcement.

Interested parties are invited to download and review the attached COSMOS Innovative Solutions Opening (ISO) ARPA-H-SOL-26-165

Amendment 01 – 17 September 2026: This amendment includes updated hyperlinks and information on the updated Solutions summary portal.

Questions and Answers – 21 September 2026: This Q&A is provided for informational purposes only and does not amend the solicitation. All other questions are due by 23 September 2026 at 5:00PM ET.

Amendment 02 – 23 September 2026: This amendment includes updates to Section 3, COSMOS Details; Section 4, Mandatory Experimental Design; as well as Correction to Figure 2.

Questions and Answers – 25 September 2026: This Q&A is provided for informational purposes only and does not amend the solicitation.

Amendment 03 – 07 October 2026: This amendment extends the submission time, now due 07 October 2026, 5:00pm ET.