It was back-patting and hand-shaking all around at Vandenberg Air Force Base in California on Tuesday after a rocket that U.S. military officials launched off the coast of Santa Barbara County intercepted and destroyed a target warhead launched from the Marshall Islands, some 4,000 miles away.

The test is a major milestone for the U.S.’s Ground-based Midcourse Defense (GMD) system and program as it marks their second consecutive successful test. It comes at a time where sabre-rattling between the U.S. and North Korea has increased in recent months with regards to launching missiles. Pyongyang has overseen at least a dozen missile tests already this year, so Tuesday’s successful launch is somewhat of a show of strength by the U.S.

However, not everyone is breathing a sigh of relief. Some experts say that while two straight successful tests is a good sign, the success rate is only 40 percent when you consider that only two of the last five tests succeeded. They also say that the last GMD test was three years ago, and with the frequency that North Korea is testing missiles, one U.S. test every three years of the GMD system is simply not enough. There are also concerns about whether the GMD can function in realistic conditions you’d see during a war, such as having to do a nighttime launch.

Guests:

Riki Ellison, founder and chairman of the Missile Defense Advocacy Alliance, a non-profit organization advocating for the deployment and evolution of missile defense; he was at the Missile Test viewing site at Vandenberg Air Force Base yesterday

Philip Coyle, senior science fellow at the D.C.-based non-profit, The Center for Arms Control and Non-Proliferation