sentences:  The sensor openings were all located together on one of the eight panels, 90 degrees from the solar panels, and protected in by a single sensor cover.The spacecraft propulsion system consisted of a monopropellant hydrazine system for attitude control and a bipropellant nitrogen tetroxide and monomethyl hydrazine system for the maneuvers in space.The bipropellant system had a total Delta-v capability of about 1,900 m/s with about 550 m/s required for lunar insertion and 540 m/s for lunar departure.