At 10:40 p.m. ET Saturday, military officials launched a mock "enemy" missile from Vandenberg Air Force Base, Calif. At 11:01 p.m. ET, they launched the "interceptor" missile from Kwajalein Atoll in the Marshall Islands, 4,800 miles away. At 11:09 p.m., the two collided 140 miles above the Pacific with a closing speed of 16,000 mph, destroying both missile and interceptor on impact.
Success? In a TIME.com Q&A, TIME Pentagon correspondent Mark Thompson assesses the Pentagon's latest hit and how far it brings us to an operational — and effective — missile-defense system.
TIME.com: How realistic was this test compared to the last one, which you likened to bowling without gutters?
Mark Thompson: This is exactly the same test as last July — plenty of guard rails. They knew exactly what time and in what direction the "enemy" missile was launched. They used a single decoy balloon, which critics argue makes it even easier for the interceptor missile as it first looks for the target. The test was exhaustively structured to succeed — but it wasn't supposed to be ready for real-life conditions.
This was an early-stage test, and a test that previously failed two times out of three. So it was imperative for the Pentagon to have some success here, and they got it. Yes, this was a charade in a lot of ways. It's also a very difficult charade, to hit a bullet with a bullet at 4.5 miles-per-second closing speed, and the Pentagon did manage to get it right. So it was a fair stepping stone.
The real pressure was political. Another miss, and they're 1 for 4, and all the people who are criticizing the program on diplomatic grounds would have been able to savage it on technical ones. It might have been fatal. Now they're 2 for 4, and as you know from baseball, .500 is a lot better than .250. The diplomatic objections aren't going away, and neither is Bush's commitment to get the program up and running. What Saturday's test said is yes, this is possible.
Possible? Doesn't a missile-defense system have to bat a lot better than 1 in 2?
Well, where they're hoping to go with this is get to a success rate of 75 or 80 percent for each interceptor missile, and count on a certain level of redundancy to go the rest of the way by launching four interceptors at each incoming missile. Multiply 75-80 percent by four, and you're up around 99-point-something percent. Which is as good as it's going to get.
When's the next test, and who's setting the schedule?
October. They now want to conduct a "major test event" at least every other month, and you know it's not a military or a technical decision — it took the Pentagon a year to get ready for this test. The speeded-up schedule is coming from the Pentagon's political leadership. Rumsfeld wants a missile shield by 2008, and you don't get to a missile shield in seven years on one test a year. You've got to crank that up.