A hush-hush military space plane and a widely publicized solar-sail experiment shared a ride into orbit on Wednesday aboard an Atlas 5 rocket launched from Florida.
The United Launch Alliance rocket rose from Cape Canaveral Air Force Station at 11:05 a.m. ET, carrying an X-37B mini-shuttle for the U.S. Air Force as well as 10 CubeSat nanosatellites that are taking a piggyback ride into space. The CubeSats were deployed a couple of hours after launch.
One of the satellites, known as LightSail, contains a 32-square-meter (344-square-foot) spread of highly reflective Mylar plastic that will be unfurled within a month to test solar sailing technology. Someday, such sails could take advantage of sunlight to propel spaceships to the far reaches of the solar system. This test, funded by the Planetary Society, is meant to clear the way for a more ambitious trial next year.
Bill Nye the Science Guy, who is the Planetary Society's CEO, said the launch marked "an extraordinary day" for the nonprofit group. He noted that the late astronomer Carl Sagan, a co-founder of the society, pressed for a solar-sail mission as far back as 1976.
"Stay tuned; the best is about to happen," Nye said in a post-launch statement.
The mission's other nine nanosatellites are funded by the National Reconnaissance Office and will test communication technologies.
The main payload is the X-37B, a 29-foot-long (9-meter-long) robotic mini-shuttle that has been going through classified, long-duration spaceflights for the Air Force. This is the fourth X-37B test flight since 2010. The previous mission, which ended last October, spent a record 674 days in orbit.
Although the X-37B's purpose has not been disclosed, experts have speculated that it could be used as an orbiting platform for reconnaissance or satellite repairs — or even as a "space bomber."
The Air Force has said this flight would test an advanced Hall thruster system that's more efficient than traditional rocket thrusters. The next-generation electric propulsion system could eventually come into play during missions to Mars.
The X-37B's payload also includes a NASA experiment known as Materials Exposure and Technology Innovation in Space, or METIS, which will study how various materials and coatings weather the harsh conditions in outer space. The results could help determine which materials will be used on future spaceships, such as NASA's Orion deep-space crew capsule.