THIS PROCUREMENT IS FOR A SPACE FLIGHT PROPELLANT TANK FOR THE PLANKTON, AEROSOL, CLOUD, OCEAN ECOSYSTEM (PACE) SPACECRAFT. THIS CONTRACT INCLUDES THE FABRICATING, TEST, INSPECT, AND DELIVER OF ONE (1) DIAPHRAGM PROPELLANT TANK, UTILIZE AN EXISTING PROPELLANT TANK SIMULATOR TO PERFORM DIAPHRAGM AND SLOSH TESTING, AND PERFORM PROPELLANT TANK VIBRATION TESTING. THE CONTRACTOR WILL ALSO PROVIDE GSFC NO-COST USE OF THEIR PROPELLANT TANK SIMULATOR FOR SUPPORTING PROPELLANT TANK CLOSE OUT WELDING. THIS SIMULATOR WILL BE SHIPPED TO GSFC UPON COMPLETION OF SLOSH TESTING. PACE IS COMPRISED OF THREE INSTRUMENTS, AN OCEAN COLOR INSTRUMENT (OCI) AND TWO POLARIMETERS (HARP2 AND SPEXONE). THE OCI IS THE PRIMARY INSTRUMENT ON THE OBSERVATORY AND IS BEING DEVELOPED AT GSFC. THE OCI IS A HYPER-SPECTRAL SCANNING (HSS) RADIOMETER DESIGNED TO MEASURE SPECTRAL RADIANCES FROM THE ULTRAVIOLET TO SHORTWAVE INFRARED (SWIR) TO ENABLE ADVANCED OCEAN COLOR AND HERITAGE CLOUD AND AEROSOL PARTICLE SCIENCE. THE POLARIMETERS ARE SECONDARY INSTRUMENTS ON THE PACE OBSERVATORY, DEVELOPED OUTSIDE OF GSFC. BOTH POLARIMETERS ARE MULTI-BAND, MULTI-ANGLE POLARIMETERS PLANNED TO MEASURE SPECTRAL POLARIZED AND UNPOLARIZED RADIANCES TO ENABLE ADVANCED CLOUD AND AEROSOL PARTICLE SCIENCE, AS WELL AS IMPROVED ATMOSPHERIC CORRECTION FOR OCEAN COLOR ACTIVITIES. THE PACE MISSION REQUIRES AN INTEGRATED PROPULSION SYSTEM. THE PACE PROPULSION SUBSYSTEM CONSISTS OF THE COMPONENTS REQUIRED TO CONTAIN, CONTROL, MONITOR, AND UTILIZE HYDRAZINE PROPELLANT TO ACCOMPLISH ORBIT MANEUVERING AND MOMENTUM MANAGEMENT REQUIREMENTS. THE PROPULSION SUBSYSTEM INCLUDES A PROPELLANT TANK, PROPELLANT FILTER, PRESSURE TRANSDUCERS, SURGE SUPPRESSION DEVICES, LATCHING ISOLATION VALVES, FILL AND DRAIN VALVES, THRUSTERS, AND INTERCONNECTING TUBING. THE PROPULSION SUBSYSTEM ALSO INCLUDES ELECTRICAL HARDWARE CONNECTING COMPONENTS TO AVIONICS AND TEST CONNECTORS, AS WELL AS HEATERS, THERMOSTATS, AND SENSORS ON THE PROPELLANT LINES AND COMPONENTS. THE SYSTEM IS AN ALL WELDED SYSTEM USING STAINLESS STEEL TUBING; ALL WELDS ARE RADIOGRAPHICALLY INSPECTED PRIOR TO THE SYSTEM PROOF PRESSURE TEST AND CHECKED FOR LEAKAGE AFTER THE SYSTEM PROOF PRESSURE TEST. THE PROPULSION SUBSYSTEM IS A MONOPROPELLANT HYDRAZINE SYSTEM USING UNREGULATED (BLOWDOWN) GASEOUS HELIUM PRESSURIZATION