The towering Sea-Based X-band Radar, a fixture at a Ford Island pier for most of the past year, left Pearl Harbor recently for the second time amid heightened concerns about North Korea’s missile program.
Navy Region Hawaii said the 280-foot-tall radar tracking system got under way March 22 "to conduct routine systems checks at sea."
CNN, however, said the Pentagon made the decision to send the SBX and at least one ship to monitor North Korea’s moves following that country’s recent provocative statements threatening to attack the United States and South Korea.
U.S. officials said a Japanese-based U.S. Navy guided-missile destroyer capable of shooting down ballistic missiles had been positioned slightly closer to the Korean Peninsula, The Associated Press reported.
The one-of-a-kind, $1 billion SBX is an advanced X-band radar mounted on a mobile, oceangoing, semisubmersible platform.
The Missile Defense Agency, which oversees the SBX as part of the nation’s ballistic missile defense system, referred questions Monday to U.S. Northern Command, which couldn’t be reached for comment.
Riki Ellison, chairman of the Missile Defense Advocacy Alliance, a nonprofit group dedicated to a robust ballistic missile defense system, said in an opinion piece Saturday that even with military exercises and a show of support for South Korea and Japan, "there is concern that we are not doing all that we can" to defend South Korea, Hawaii and other Pacific locations from a North Korean nuclear missile first strike.
Among other steps, Ellison recommended deployment of the SBX between Hawaii and North Korea to provide fire control data to U.S. Navy Aegis ballistic missile defense ships and ground-based interceptors in Alaska and California.
White House press secretary Jay Carney said Monday that U.S. actions taken in response to North Korea are "prudent" and have not contributed to escalating tensions.
"I would note that despite the harsh rhetoric we’re hearing from Pyongyang, we are not seeing changes to the North Korean military posture, such as large-scale mobilizations and positioning of forces," Carney said.
The phased-array radar inside the SBX’s inflatable dome tracks missile paths with 45,000 transmission and receiving elements and is so powerful it could see a baseball flying through the air 2,500 miles away, according to the Missile Defense Agency.
The radar, which has the appearance of a giant golf ball on a six-legged platform, sailed out of Pearl Harbor on March 23, 2012, about three weeks ahead of what ended up being a failed April 13 North Korea rocket test.
The SBX returned to Pearl Harbor in late May. Asked at the time whether the radar ship monitored the North Korean launch, Pam Rogers, who was then a Missile Defense Agency spokeswoman, said, "We can’t discuss the nature of the SBX’s operations."
The Missile Defense Agency said in February 2012 that it planned to sideline the missile tracker by placing it "in a limited test and contingency operations status" to save $500 million over five years.
The change was detailed as part of the Defense Department’s budget request for 2013, which proposed $487 billion in cuts over the next 10 years that are separate from sequester cuts.