WASHINGTON (NASA HQ PR) — NASA has selected four mission proposals submitted to the agency’s Explorers Program for further study. The proposals include missions that would study exploding stars, distant clusters of galaxies, and nearby galaxies and stars.

Two Astrophysics Medium Explorer missions and two Explorer Missions of Opportunity have been selected to conduct mission concept studies. After detailed evaluation of those studies, NASA plans to select one Mission of Opportunity and one Medium Explorer in 2024 to proceed with implementation. The selected missions will be targeted for launch in 2027 and 2028, respectively.