MESSENGER Settles into Eight-Hour Orbit Around Mercury, Poised for New Discoveries

MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., conducted the second of two maneuvers required to reduce the spacecraft's orbital period about Mercury. The first maneuver, completed on Monday, shortened the orbital period from 11.6 to 9.1 hours and consumed the remaining oxidizer, one of two propellants that fuel the higher-efficiency large thruster. With today's maneuver, accomplished with the spacecraft's four medium-sized thrusters, MESSENGER is now in the 8-hour orbit from which it will operate for the next year.