SmallSat revolution: Physicist Vanderlei Martins explains the rise of tiny spacecraft

Right now, almost 500 SmallSats—spacecraft from the size of a refrigerator to a golf ball—are orbiting 200 miles above Earth’s surface, and 78 percent of them launched after 2013. In The Conversation, Vanderlei Martins explains the skyrocketing numbers of SmallSats and the important contributions they are making to scientific research focused on Earth and beyond.

“These SmallSats are poised to change the way we do science from space,” says Martins, professor of physics at UMBC. They are more affordable than larger satellites, and the most basic are almost within reach for serious hobbyists. The lower price tag has allowed countries such as Poland, Pakistan, Colombia, and others to launch their space programs for the first time and contribute to the global quest for knowledge.

The first SmallSat launch in 1999, by a team at Stanford University, was a proof of concept to demonstrate that something so small could survive in space. “Like all space explorers, [SmallSats] have to contend with vacuum conditions, cosmic radiation, wide temperature swings, high speed, atomic oxygen, and more,” explains Martins.

Since the first launch, and particularly in the last few years, SmallSats have become much more sophisticated. Now they not only survive in space, but also carry complex scientific instruments to collect all kinds of data and send it back to Earth. SmallSats currently in orbit “aim to answer specific science questions, covering a broad range of sciences including weather and climate on Earth, space weather and cosmic rays, planetary exploration and much more,” says Martins. They also “serve as pathfinders for bigger and more expensive satellite missions.”

Martins leads the team responsible for the Hyper-Angular Rainbow Polarimeter (HARP) SmallSat, scheduled to launch in June 2017. HARP “observes interactions between clouds and aerosols—small particles such as pollution, dust, sea salt, or pollen, suspended in Earth’s atmosphere,” explains Martins. These interactions affect cloud formation and precipitation, which affect Earth’s global water cycle, energy balance, and climate.

HARP’s capabilities reflect rapid improvements in SmallSat technology. “It’s an example of the kind of advanced scientific instrument it wouldn’t have been possible to cram onto a tiny CubeSat in their early days,” says Martins.

Still, SmallSats do have limitations. Although HARP could conceivably collect data continuously, a compact power supply limits how much data it can send back to Earth. Researchers at a new interdisciplinary center at UMBC will analyze and interpret the data it does send back, which, though limited, is still expected to be robust and insightful.

As SmallSat technology continues to improve, “seeing what works and what doesn’t will help inform larger space missions and future operations,” says Martins. In their pathfinding role, “the next generation of nanosatellites will advance the frontiers of science.”

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Image: Vanderlei Martins in his lab at UMBC with the HARP CubeSat. Photo by Marlayna Demond ’11 for UMBC.