1. North Korea launched a multi-stage rocket in December from its base at Sohae, and the satellite it carried seemed to reach orbit, though U.S. officials claimed that it was tumbling out of control. Tuesday, the U.N. Security Council voted to condemn the launch.

    That vote spurred a new round of threats from North Korea.

    "Settling accounts with the U.S. needs to be done with force, not with words, as it regards jungle law as the rule of its survival," The North's National Defense Commission, headed by the country's young leader, Kim Jong Un, said Thursday.

    The United States and its allies have always held that the North Korean rocket program is cover for weapons development, begging the question, "What kind of danger do North Korean rockets and bombs pose to the United States and the rest of the world?"
  2. This Sept. 17 satellite image provided by DigitalGlobe and annotated by the U.S.-Korea Institute at Johns Hopkins School of Advanced International Studies, 38North, shows a facility in Sohae, North Korea, where analysts believe rocket engines have been tested in a sign North Korea continues to develop its long-range ballistic missiles. The analysis provided to The Associated Press is based on satellite images taken as recently as late September of the Sohae site on the secretive country's northwest coast. (AP)

  3. Why worry? 

    North Korea is not a fan of the United States. More than 60 years after the beginning of the Korean War, America features prominently in the so-called Hermit Kingdom's propaganda. North Korea tested nuclear weapons in 2006 and 2009, making it a top concern for the United States. North Korea, however, lacks the rocket technology to directly strike America. 

    It's a lack they've been trying to address.
  4. A North Korean soldier stands in front of the country's Unha-3 rocket that launched April 12 from a launching site in Tongchang-ri, North Korea. (AP)
  5. On April 12, Kim Jong-un — who had recently succeeded his father Kim Jong-il as absolute leader of North Korea — launched the Unha-3 (Galaxy-3), despite an agreement reached just months before with the United States that would have precluded such a test.

    The three-stage rocket, which analysts believe is loosely based on Soviet and Iranian technology, according to Space.com, didn't make it far. It exploded only a few minutes after launch.

    The rocket launched in December is thought to be similar in design.
  6. Are we in danger today?

  7. This graphic, provided by Space.com, details what's known about the Unha rocket.
  8. It's estimated that a rocket like the Unha-3 should have the range to strike the United States mainland, with San Francisco among the potential targets that may now be in range.

    But one success doesn't mean that North Korea has mastered ballistic missiles. Past launches, in 1998, 2006, 2009 and in April, all ended in failure. The Associated Press wrote an article headlined "North Korea launch highlights all that can go wrong with rockets," that offers an explanation. It all boils down to the fact that rocket science is really hard, the AP says.

    Still, December's launch represented a milestone that was wildly celebrated in North Korea, and analysts say it also served to strengthen Kim's position within his own government. If North Korea learns to build nuclear bombs small enough to fit on top of a rocket, the threat the Hermit Kingdom poses to the rest of the world grows immeasurably.