An in-house exploratory development program was accomplished as part of an inter-laboratory team effort to demonstrate the feasibility of hybrid propulsion for the Sandpiper high-performance target missile. The objectives of this program were to 1 conduct off-design tests of a flight type heavyweight Hybrid thrust chamber assembly TCA 2 conduct flight certification tests on flight weight propulsion systems delivered under a concurrent AFRPL contract and 3 provide propulsion system field servicing and engineering support during subsequent flight tests of the propulsion system. Thirty heavyweight TCA tests were conducted, and TCA component operating characteristics, TCA component durability, effects of metal fuel grain additives on combustion, effects of fuel grain temperature on combustion, effects of IRFNA oxidizer substitution, and TCA altitude performance were evaluated. MON- 25 oxidizer and 90 Plexiglas 10 magnesium metal fuel were the propulsion system propellants. Eight flight weight propulsion systems were tested over simulated mission duty cycles after being subjected to environmental extremes of temperature -65 F to 165 F and humidity.