CubeSats: Tiny Satellites Can Do Big Science

Tiny Satellites Can Do Big Science

When it comes to laptop computers and cell phones, bigger isn't better. The same logic applies to satellites: the bulkier the satellite, the more time it takes to design and build, and the more expensive it is to put into orbit.

Researchers are now taking advantage of the electronics technologies that have made personal gizmos compact and affordable to make satellites that weigh and cost a fraction of their predecessors. These pocket- and backpack-sized satellites are changing the way astrobiology research is done.

Conventional satellites used for communications, navigation or research can be as large as a school bus and weigh between 100 and 500 kilograms. Universities, companies and NASA are now building small satellites that weigh less than one kilogram (picosatellites) or up to 10 kilograms (nanosatellites).

These small satellites can be considered miniature versions of full-size counterparts. They contain the same components—battery, orbital control and positioning systems, radio communication systems, and analytical instruments—except everything is smaller, less expensive and sometimes less complicated.

"That's the beauty of this technology," says Orlando Santos, an astrobiologist at NASA Ames Research Center. "We can make these things small and still get meaningful science out of them."

The Rise of the Cube
Two decades ago, Bob Twiggs and his students at Stanford University developed the first picosatellite the size of a Klondike ice cream bar. The Aerospace Corporation launched these picosatellites as part of a mission to demonstrate the feasibility of building little satellites that communicate with each other.

Twiggs then worked on CubeSat, a 10-centimeter cube. "I got a 4-inch beanie baby box and tacked on some solar cells to see how many would fit on the surface," Twiggs says. "I had enough voltage for what I needed so I decided that would be the size."

Jordi Puig-Suari at California Polytechnic State University built a deployment mechanism called the poly picosatellite orbital deployer, or P-POD, that could pack up to three CubeSats. One of these is typically the satellite bus, the brains of the satellite containing positioning and radio equipment, while the other cubes carry the scientific experiments. In 2004, the researchers sent the first three-cube nanosatellite into orbit.

Six years later, CubeSats have become the world-wide standard for small satellites. They are being used for everything from environmental sensing and fundamental biology research to testing new spaceflight systems.

Over 60 universities and high schools are part of the CubeSat Project based at Cal Poly. The National Science Foundation and the U.S. Air Force have programs that funds CubeSats for atmospheric and space weather research. Aerospace companies such as Lockheed Martin and Boeing have also built and flown CubeSats.

Kentucky-based NanoRacks LLC provides a platform to take CubeSat experiments as cargo aboard the Space Shuttles to the International Space Station for periods of 30 or 60 days, after which they bring the cubes back.

The goal of NASA's new CubeSat Launch Initiative is to radically open up the flight opportunities for nanosatellites. This Initiative should also make it easier for universities to compete for launch access on NASA launch vehicles.

There are probably between 35 and 40 small satellites orbiting the Earth right now, of which about a quarter might still be working, says Twiggs, now a professor at Morehead State University's Space Science Center in Kentucky.