CubeSat: The little satellite that could
One day in 2003, an SS-18 Dnepr rocket lifted off from a launch site in northern Russia. Dubbed the “Satan” rocket by NATO forces, Dneprs were built to deliver nuclear warheads, but most had been converted for commercial use with the dissolution of the Soviet Union.
So it came to be that on this day, the Dnepr in question would deliver satellites into orbit. But, even in that regard, this mission was special. The payload included the very first CubeSat. As satellites go, the CubeSat was, and still is, a marvel. Inexpensive and quick to build, the first CubeSats measured just 4 inches on any side, were cobbled together from off-the-shelf computer chips, radios, cameras and other parts, and programmed for just a single task. That 2003 launch became something of a Sputnik moment for CubeSat. Today, CubeSat has seen over 1,600 successful deployments and by 2026 the CubeSat industry is expected to reach $7.4 billion.
Not bad for something that began as a student project in the late 1990s at Stanford University. CubeSat was the brainchild of Bob Twiggs (MSEE ’63), a consulting professor in the Space Systems Development Laboratory in the Department of Aeronautics and Astronautics, and his collaborator Jordi Puig-Suari at the California Polytechnic University.
“It was a great student project. The aerospace companies started telling us the students they are seeing are really good. They come out and they have good experience,” Twiggs notes. “But, back then, we weren’t sure they would ever see orbit.”
As conceived, Twiggs simply wanted to teach the principles of satellite design by building a working satellite on a shoestring within the span of a single year-long master’s degree program. An earlier effort, yielding a satellite about the size of a hatbox, had taken six years to complete.
“The whole idea was to get the students some real hands-on experience building a complete satellite,” Twiggs says. “But I was having a hard time getting them to finish the satellite during the program and each subsequent group would redesign what the previous one had done.”
The industry was skeptical. Even Twiggs’ own boss at Stanford, George Springer, was unsure about the practical implications of CubeSat. But Twiggs pressed ahead. He found inspiration in the most unlikely of places – a toy store. The 4-inch cube is just about the size of a Beanie Baby box, Twiggs says proudly.
“I thought if we could put a solar panel on all sides we could power the thing and that was why that size became the target.”
Equally critical to CubeSat’s success, as a student project at least, was the fact that its capabilities and technologies were fully testable on the ground. Unsure their projects would ever make orbit, some students hoisted their prototypes into the air with balloons to test radio communications.
The original CubeSats used VHF radios, just like those used to transmit television signals and handheld radios at sea. The antenna, flying above the Durand Building on the Stanford campus, looked just like a V-shaped TV aerial of old. In fact, each CubeSat required its own ham radio license to operate and had to be approved by the FCC.
“Everybody thought that was a stupid idea, especially most of the aerospace guys that built big satellites,” Twiggs says. “We didn’t care.”
From humble beginnings, CubeSat has disrupted an industry. It was a far cry from the expensive and intricate behemoths being sent into space at the time. Costing only about $5,000 to build and $30,000 each to launch, CubeSat put satellite technology within reach of even the smallest of companies – and countries. For many nations, CubeSat launches represented their first-ever forays into the satellite age.
Soon others began to take note of the favorable economics and began to imagine what networks of CubeSats might accomplish in unison. As the size, cost, and capability of off-the-shelf components steadily declined, as did budgets for satellites in general, CubeSat began to catch on. A CubeSat can be built and launched in just 8 months, far faster than conventional satellites.
“Some of these hundred-million-dollar satellites, it takes 10 years to build them. By the time you get the thing launched it might have 10-year-old parts,” Twiggs says of the speed-to-market advantages.
While Twiggs was always confident of CubeSat’s educational value, its myriad commercial applications came as something of a surprise. Companies today are using networks of CubeSats to track cargo ships and airplanes. Others are using cameras to provide detailed remote imaging. One company used CubeSat to sense earthquakes by the magnetic fields created when sides of a fault grind against one another.
“Every day I see something amazing,” Twiggs says.
Twiggs’ design remains the de facto standard in the industry and Twiggs is credited not only with the original idea and design of the CubeSat, but also with the design of a clever launcher able to carry and then deploy several CubeSats at time.
“Other satellite companies didn’t want their $100 million satellites being launched with a bunch of cubes possibly bouncing around in the payload bay,” Twiggs remembers. “We had to come up with something better.”
Twiggs responded with what amounts to a Pez dispenser for CubeSats. The spring-loaded launcher, holding three or more CubeSats at a time, can be affixed in the payload bay and deployed as a single unit, and then pop CubeSats into orbit once far removed from other valuable payload on board the rocket.
“It’ll spit them out in ribbons, if you want,” Twiggs says.
Twiggs has been hailed as “Father of the CubeSat” and showered with accolades in recent years, including being inducted with Puig-Suari into the Space Technology Hall of Fame by Space & Satellite Professionals International, and being named as one of 10 engineers “Who Made a Difference in Space” by Space News.
Through it all, neither Stanford nor Twiggs ever patented the CubeSat design. It remains open source and freely available to all who are interested.