North Korea’s much-anticipated rocket launch ended quickly in failure Thursday, splintering into pieces over the Yellow Sea soon after takeoff, according to South Korean and U.S. officials.

The launch nevertheless rattled the United States and its allies, with the Pentagon dispatching the giant Sea-Based X-Band Radar to sea from Hawaii ahead of the launch.

A half-dozen U.S. Navy anti-missile ships with detection and shoot-down capability also were standing by in the region, according to CBS News.

Two Pearl Harbor-based Aegis ballistic missile defense destroyers had their missions altered, with the USS Russell’s seven-month deployment extended and the USS O’Kane rerouted in the Sea of Japan.

Three Japanese destroyers with shoot-down capability also were deployed.   

In Pyongyang, the North Korean capital, the government acknowledged in a noon announcement broadcast on state TV that the satellite failed to enter into orbit. 

The launch had proceeded despite protests from the U.S., South Korea and other countries that called the launch a cover for a test of missile technology. North Korea said the rocket was part of a peaceful effort to send a satellite into space to the commemorate the anniversary of its founder’s birth.

In response to the launch, Washington announced it was suspending plans to contribute food aid to the North in exchange for a rollback of its nuclear programs.

North Korean state media said the Kwangmyongsong-3 satellite was fired from the Sohae Satellite Launching Station in Tongchang-ri along the west coast at 7:38 a.m. Friday.

“The earth observation satellite failed to enter its preset orbit, the state-run Korean Central News Agency said. “Scientists, technicians and experts are now looking into the cause of the failure.”

The rocket exploded in midair one or two minutes, said Maj. Gen. Shin Won-sik, a South Korean Defense Ministry official.

The U.S. North American Aerospace Defense Command said officials detected and tracked the launch of the rocket — which it called a missile — over the Yellow Sea; the first stage fell into the sea 165 kilometers (100 miles) west of Seoul, while stages two and three failed.

“At no time were the missile or the resultant debris a threat,” NORAD said in a statement.

North Korea had insisted it would not back down, and said the rocket would carry only a civilian satellite, touting it as a major technological achievement to mark the 100th anniversary of the birth of the country’s founder, Kim Il Sung, on Sunday.

Still, the rocket failure is a major embarrassment for Pyongyang, which has invited dozens of international journalists to observe the rocket launch and other celebrations.

It has staked its pride on the satellite, seeing it as a show of strength amid persistent economic hardship while Kim Il Sung’s grandson, the 29-year-old Kim Jong Un, solidifies power following the death of his father, longtime leader Kim Jong Il, four months ago.

“It blows a big hole in the birthday party,” said Victor Cha, former director for Asia policy in the U.S. National Security Council, contacted in Washington. “It’s terribly embarrassing for the North.”

He said the next step would be to watch whether North Korea conducts a nuclear test, as has been speculated by the South Korean intelligence community. North Korea is reportedly making preparations for such a test soon.

“We have to watch very carefully what they are doing now at the nuclear test site and how they explain this with all those foreign journalists in the country,” Cha said.

Tokyo, which was prepared to shoot down any rocket debris that jeopardized its territory, also confirmed a launch from North Korea.

“We have confirmed that a certain flying object has been launched and fell after flying for just over a minute,” Japanese Defense Minister Naoki Tanaka said. He said there was no impact on Japanese territory.

North Korean space officials said the Unha-3, or Galaxy-3, rocket was meant to send a satellite into orbit to study crops and weather patterns — its third bid to launch a satellite since 1998. Officials took foreign journalists to the west coast site to see the rocket and the Kwangmyongsong-3 satellite Sunday in a bid to show its transparency amid accusations of defiance.

“For all their advanced technology, these rockets are fairly fragile things,” said Brian Weeden, a technical adviser at Secure World Foundation and former Air Force officer at the U.S. Space Command. “You’re looking at a metal cylinder that has fairly thin walls that contains a lot of high pressure liquid.”

Weeden said the launch appeared to be a failure of both space and missile objectives.

“The earlier it breaks up, the less data you’ve collected, so the less useful that test is likely to be,” he said. “It’s very likely that the U.S. and its allies probably gathered more information about this test than the North Koreans have.”

More U.S., Japanese and South Korean military assets were in place than ever before to monitor the launch — and it was expected to provide vital data on North Korea’s ballistic missile capabilities. A U.S. satellite is believed to have provided the first confirmation of the launch, according to Japanese media reports.

Cmdr. Michael Ray, commanding officer of the Hawaii-based guided missile destroyer O’Kane, said Sunday on the ship’s Facebook page that the warship was in the Sea of Japan and had “unexpectedly turned north from the route we anticipated and are now braving the cold weather of Northeast Asia.”

The ship’s SPY-1 primary air search radar, essential to its ballistic missile defense mission, had experienced a “catastrophic” electronic malfunction on the eve of a high-priority tasking, but the crew was able to repair the radar back to full capacity in time for its mission, which Ray said was “huge news.”

The Pearl Harbor-based destroyer Russell, meanwhile, received new mission orders just as it was preparing to return to Hawaii from a seven-month deployment to the Western Pacific and Middle East.

“It is not clear how long the delay will be or when exactly we will return from deployment,” Cmdr. Joseph Carrigan said March 24 on the Russell’s Facebook page. “Regrettably, due to concerns about operational security, I am unable to provide more details than these.”

Cmdr. Leslie Hull-Ryde, a Pentagon spokeswoman, said ahead of the North Korean launch, “We are not going to discuss military operations, plans or intelligence. However, we stand ready to defend U.S. territory, our allies and our national interests.”

CNN reported that the towering sea-based radar, which was built on an oil platform and often stops in Pearl Harbor, was deployed as a “precautionary” move. 

U.S. Navy minesweepers and other ships are in the area and expected to now begin scouring the seas for debris from the rocket, which can offer evidence of what went wrong and what rocket technology North Korea has.

Scott Pace, the director of the Space Policy Institute at George Washington University, said the North will be hard pressed to get any international help in recovering its lost rocket.

“I would not expect the North to receive any help in understanding what may have gone wrong,” he said. “The failure will certainly not be good for the engineers and managers responsible.”

The United States, Britain, Japan and others have called such a launch a violation of U.N. resolutions prohibiting North Korea from nuclear and ballistic missile activity.

Experts say the Unha-3 carrier is the same type of rocket that would be used to launch a long-range missile aimed at the U.S. and other targets. North Korea has tested two atomic devices but is not believed to have mastered the technology needed to mount a nuclear warhead on a long-range missile.

Economist Marcus Noland, a non-resident senior fellow with the East-West Center in Honolulu and deputy director of the Peterson Institute for International Economics, said in a piece today on the East-West Center’s website that the North Korean economy is characterized by macroeconomic instability, widening inequality and growing corruption.

“No one — including the North Korean government — knows with any true confidence the size or growth rate of the country’s economy, but the consensus among outside observers is that per capita income today is lower than it was 20 years ago, and by some reckonings is only now re-attaining the level it first achieved in the 1970s,” Noland said.

Help was supposed to be on the way in the form of a resumption of U.S. aid, but the unraveling of the food-for-weapons deal in the wake of North Korea’s announcement of its rocket launch means that conditions for the North’s chronically food-insecure population may not improve, he said.

U.S. Secretary of State Hillary Rodham Clinton, speaking for the Group of Eight nations after their foreign ministers met in Washington, said Thursday that all the members of the bloc agreed to be prepared to take further action against North Korea in the Security Council if the launch went ahead.

“Pyongyang has a clear choice: It can pursue peace and reap the benefits of closer ties with the international community, including the United States; or it can continue to face pressure and isolation,” Clinton said.

The U.N. Security Council has scheduled a meeting Friday on the North Korea launch.

South Korean President Lee Myung-bak convened an emergency security meeting, and officials agreed to closely monitor North Korea’s nex