Chris McLean, (right) principal investigator for NASA’s Green Propellant Infusion Mission at Ball Aerospace, and Joe Cassady, (left), executive director of space at Aeroject Rocketdyne, explain the payload during a NASA prelaunch technology TV broadcast for the Space Test Program-2 (STP-2) mission at NASA’s Kennedy Space Center in Florida on June 23, 2019. The payload will help demonstrate this low toxicity, increased performance propellant and related systems so it can become a viable solution for future satellites. It is one of four NASA payloads scheduled to launch on a SpaceX Falcon Heavy rocket from Launch Complex 39A beginning at 11:30 p.m. EDT on June 24, 2019. STP-2 is managed by the U.S. Air Force Space and Missile Systems Center.