Spate of hypersonic vehicle tests fuels global strike debate.

• Author: Magnuson, Stew
• Position: HYPERSONIC AIRCRAFT

The military's reusable space plane, the X-37B, and its classified payload lifted off in April only one day after the maiden flight of the Defense Advanced Research Projects Agency's Hypersonic Technology Vehicle-2 suborbital glider. It flew nine minutes before operators lost its signal and were forced to abort the mission.

These two vehicles, along with a hypersonic missile that made its first test flight one month later, the X-51 WaveRider, have all been mentioned as means to carry out the "prompt global strike" concept, which calls for the U.S military to deliver a conventional warhead anywhere on the planet in significantly shorter time spans than are currently possible.

Intelligence can be fleeting. The location of a high-value target such as a terrorist leader can be confirmed, but he may move before an air strike is arranged. Or he could be located in a nation that doesn't allow the Air Force to fly over its territory. U.S. Strategic Command has been looking into ways to deliver bombs on such targets for several years.

The X-37B's top-secret payload has non-proliferation experts wondering if it is meant to deliver weapons. Air Force leaders won't say how high up the experimental spacecraft is, how much it costs, or exactly how long it will loiter before returning to Earth. And it definitely won't reveal what it is carrying in its bay.

"I think the secrecy is the key problem--not necessarily the technology, itself--it does allow people's imaginations to run wild," said Theresa Hitchens, director of the United Nations Institute for Disarmament Research in Geneva, Switzerland.

"The concept of 24/7 global strike capabilities makes almost everyone nervous, including U.S. allies," Hitchens said.

"Such capabilities could be highly destabilizing in a crisis; and also raise the risk of mistaken strikes because of the pressure to respond rapidly to intelligence without taking the time to closely verify that intelligence," she told National Defense in an email.

Diplomats based in Europe have asked Hitchens her opinion about the space plane, formally known as the orbital test vehicle. "The X-37B has caused quite a stir in China, at least in the Chinese press and there have been some pointed inquiries here," she said.

"The problem is primarily the heavy secrecy surrounding the experiment, which always causes the international community to become suspicious when it involves U.S. military space activities," she added. She believes the X-37B is...