"The Air Force now has a policy of acquiring capabilities rather than missions, so some general somewhere probably thinks it would be spiffy to have a space plane that can launch at short notice," he said. "It's worthwhile learning lessons from the shuttle and how to do turn-arounds cheaper."
Mystery surrounds the actual missions being undertaken during these flights, but McDowell thinks it's serving a similar role as the space shuttle by carrying a science or intelligence payload.
"I believe it's testing some kind of experimental sensor for the National Reconnaissance Office; for example, a hyperspectral imager, or some new kind of signals intelligence package," said McDowell. "The sensor was more successful than expected, so the payload customer asked the X-37 folks to keep the spacecraft in orbit longer."
That theory is backed up by comments made by the Air Force to The Christian Science Monitor before its first flight that it would be involved in "various experiments" that will allow "satellite sensors, subsystems, components and associated technology" to be taken to space and back.
Another clue to the X-37B's role might be in its control within the Air Force's Rapid Capabilities Office, a Washington, D.C., unit that attempts to fast-track new technologies to help deal with specific threats that might have a short lifespan. That's distinctly different from the rest of the Air Force's space operations.
The Rapid Capabilities Office officially reports to senior U.S. military leaders but also, according to Aviation Week and Space Technology, exists as a "little acknowledged interface between the Air Force and the intelligence community."
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