Why a 10-centimeter cube? The trademark size of the CubeSat emerged somewhat accidentally, recalls Jordi Puig-Suari, an aerospace engineer at California Polytechnic State University. Student-built satellites date back to the 1980s, but they were often unwieldy. Not only were they expensive to launch, but commercial rocketeers were also wary of packing them alongside primary payloads. But in 1999, Puig-Suari met with Bob Twiggs, at the time an aerospace engineer at Stanford University, to discuss ways of getting more student projects into space. They focused on slimming down the spacecraft. They thought hard about the potential capabilities of a 10-centimeter cube with a mass limit of 1 kilogram and found the perfect life-size demonstration model: a plastic box used for storing Beanie Babies. A standard was born. In 2003, the first six student projects rode a Russian Eurockot into orbit, for about $30,000 a pop; early on, the biggest single expense was the ride, though in recent years, launch prices have stayed put around $100,000 for a 1U CubeSat. Many early CubeSats tackled problems in space weather, but other areas of science are opening up, and some scientists think CubeSats can play a role far beyond low-Earth orbit. CubeSats are also opening space to new participants; Bruce Yost, deputy manager of the small spacecraft integrated product team at NASA's Ames Research Center in Mountain View, California, calls it "the democratization of space."
To read the full story, see the 10 April issue of Science.