Mississippi sent a military police company to Washington to help with security during the inauguration last month. But another National Guard unit is returning home Tuesday after a longer and even more sensitive mission in the nation's capital. The 1st Battalion, 204th Air Defense Artillery Regiment headquartered in Newton spent almost a year manning missile batteries to protect potential targets like the White House, the U-S Capitol and the Pentagon. This is the fourth time the Mississippi soldiers have carried out the mission since becoming the first National Guard unit to do so in 2003. The battalion also sent some of its troops to Europe on a training mission last year. Those soldiers returned home Friday.