X-37B (climbing (off-planet -earth) approach vehicle)

May 16, 2010 - 09:31pm PT


A German named Eugen Saengler invented the idea back in 1935 with his Silbervogel.

It requires a great deal of energy to change the orbital plane of a spacecraft; almost as much as the energy to launch it. Saengler published papers proposing a vehicle that could descend into the upper atmosphere and use aerodynamic effects to change its orbital plane, and then skip back off into space like a skipping stone on a pond.

The USAF picked up on the idea in the late 1950s with the Dyna-soar space program as a successor to the X-15. In my opinion it was for various reasons our best idea for space vehicles. That program produced the X-20 and X-24 that proved the re-entry concepts that were later used for our Space Shuttle Program. Dyna-soar was canceled in favor of a civilian space launch program: the Vanguard, that didn't turn out too well.

The X-37 mini-shuttle is somewhat of a revitalization of that idea. It was sitting partially forgotten in a hanger at NASA Dryden for years, and I was privileged to spend hours crawling around admiring it. Recently the USAF picked up on the idea and launched it. It can stay up much longer than a couple of weeks.

I don't know much more than that as to what the USAF has in mind for it, but it's not difficult to imagine the advantages of an eye in the sky that can rapidly change orbits.

There are several commercial ventures that are currently taking advantage of the research done for the Dyna-soar program. I am a big promoter of the idea of a very small vehicle that is closer to a powered skydiver than a spaceplane.

Another German, Alban Geisler, is developing this idea with his SkyRay and Gryphon; with a version marketed through SpelCo. They have made many hundreds of test flights. The mini-jet turbine and solid-rocket powered Gryphon wing is air-launched at high altitude from a cargo plane with a skydiver pilot in a pressure suit, with fly-by-wire flight stabilization, seamless transition from aerodynamic control to thruster control, and helmet-mounted full avionics display. I think this idea will have the same impact on space travel as the personal computer relative to mainframe computers.