The Missile Defense Agency’s big Sea-Based X-Band Radar tracking ship sailed out of Pearl Harbor on Friday — about three weeks ahead of North Korea’s planned space launch.

Pam Rogers, an MDA spokeswoman, said she couldn’t discuss the radar’s operations and whether it will be used to monitor the upcoming rocket test.

The towering radar tracker "is returning to sea to continue its mission as a part of the ballistic missile defense system," she said today.

Where the radar will operate also is unclear, but it doesn’t have to be near the Korean Peninsula to track the space launch. MDA officials in the past have said the radar could track a baseball-sized object flying through space on the East Coast while the SBX was on the West Coast.

North Korea said last month it was suspending nuclear and long-range missile testing in exchange for food aid from the United States, then announced March 16 that it would send into space an Earth observation satellite to mark the 100th birthday of late President Kim Il Sung.

The planned launch, which North Korea said will take place between April 12 and 16 on a long-range Unha-3 rocket, has been condemned by the United States as a ballistic missile test and destabilizing for the region.

In June 2009, then-Defense Secretary Robert Gates ordered the SBX missile tracker — which was in Pearl Harbor at the time — to sea as North Korea prepared a space launch with Hawaii in the flight path.