In what seemed intended as a display of technological advance, Iran said on Wednesday that it had fired a rocket into space carrying living organisms — a rat, two turtles and worms, according to the state-run Press TV.

South Korea plans to launch a satellite into space using technology capable, in theory, of eventually delivering nuclear warheads or other weapons of mass destruction. Proliferation experts say the launch is problematic, even if South Korea, a close U.S. ally, says it is for scientific purposes.

Top Pentagon officials have grown increasingly confident in the nation's missile defense system at a time when North Korea is threatening to conduct a long-range launch, leading to speculation of a possible showdown in the exosphere.

The authors suggest that a ban on ballistic missile tests could "enhance global security by increasing decision-making time, removing the threat of accidental missile launch, and having an immediate positive impact on the most volatile areas of emerging international arms competition."

North Korea may be capable of hitting West Coast cities with its missiles within three years, according to Marine Gen. James Cartwright, the vice chairman of the Joint Chiefs of Staff, but is unlikely to be able to deliver a nuclear warhead in that time frame.

With support from outside sources, Iran within six years could produce an ICBM capable of hitting the United States, the U.S. Air Force's National Air and Space Intelligence Center said in a new report made public yesterday by the Federation of American Scientists.

Nonproliferation experts yesterday recommended the U.N. Security Council pass a resolution to spell out the difference between a ballistic missile launch and a space vehicle launch. The ambiguity between the two kinds of events has been of particular importance in the wake of North Korea's April 5 rocket launch.

Sunday's failure of an improved version of the North Korean Taepo-Dong-2 has deprived U.S. intelligence agencies from assessing performance of the vehicle's third stage. This is deemed critical to determining the precise threat the vehicle poses as an ICBM that could attack Alaska, Hawaii or deeply into the continental U.S.

North Korea failed in its highly vaunted effort to fire a satellite into orbit, military and private experts said Sunday after reviewing detailed tracking data that showed the missile and payload fell into the sea. Some said the failure undercut the North Korean campaign to come across as a fearsome adversary able to hurl deadly warheads halfway around the globe.