Starting later this month, NASA plans to launch a group of very tiny satellites into space.
These cutting-edge devices will orbit the Earth, taking atmospheric measurements, monitoring storms, and studying factors associated with climate change. They will also serve as tiny stepping stones toward NASA's new focus on small satellites, or "smallsats," as an alternative to bulkier traditional satellites.
Smallsats have a number of advantages over larger devices. Tiny satellites are cheaper to launch, since they are lighter and take up less space. They are also faster and easier to build, allowing researchers to take more risks than they could with a large, expensive piece of equipment.
The suite of new satellites set to enter space range in size from a loaf of bread to a small washing machine. The first six smallsats will hitch rides over the next year on other rockets headed into orbit with normal-sized payloads.
The first of these hitchhikers will be the Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) satellite later this month. RAVAN is designed to detect energy fluctuations near the edge of Earth's atmosphere, providing valuable data on the effect of greenhouse gases on climate change.
RAVAN is a CubeSat, a type of small satellite that NASA developed to allow educational and non-profit institutions with a means to conduct experiments in space for relatively low cost. CubeSats have standard dimensions of 10x10x11 cm (about 4 inches on a side) and weigh less than 3 pounds per unit. Two more CubeSats will follow RAVAN early next year.
"NASA is increasingly using small satellites to tackle important science problems across our mission portfolio," said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington, in a statement. "They also give us the opportunity to test new technological innovations in space and broaden the involvement of students and researchers to get hands-on experience with space systems."
These innovations include IceCube, which uses a new kind of high-frequency microwave radiometer to measure the presence ice in clouds; the Hyper-Angular Rainbow Polarimeter (HARP), which will measure particles in the atmosphere and the distribution of the size cloud water droplets; and the Microwave Radiometer Technology Acceleration satellite (MiRaTA), which has almost all the capabilities of a full-sized weather satellite while being the size of a shoebox.
This new suite of satellites reflect a significant shift in focus among NASA researchers away from traditional research satellites and toward swarms of small devices in orbit.
"Small satellites have several advantages," said Ellen Stofan, chief scientist at NASA Headquarters, during a teleconference. "They reduce the risk and cost of demonstrating precursor technologies and infusing them into larger flight projects. They're used for flight testing and demonstrating new proof-of-concept components. And they enable affordable, distributive science observation systems using constellations or swarms of small satellites to achieve broad coverage."
Satellite swarms are already yielding significant innovations. A swarm of eight Cyclone Global Navigation Satellite System (CYGNSS) microsatellites, due to launch in December, will orbit in the Earth in an evenly-spaced formation to gather data on how tropical storms and hurricanes develop.
"It's not cookie cutter," said Jim Wells, the NASA Langley mission manager of CYGNSS, in a statement. "It's a one-of-a-kind, hasn't-been-done-yet deal."
NASA scientists hope that pioneering satellite concepts like CYGNSS and CubeSats will lead to new and better ways of understanding our planet from orbit.
"The affordability and rapid build times of these CubeSat projects allow for more risk to be taken, and the more risk we take now the more capable and reliable the instruments will be in the future," said Pamela Millar, NASA's Earth Science Technology Office (ESTO) flight validation lead.
"These small satellites are changing the way we think about making instruments and measurements," she said. "The cube has inspired us to think more outside the box."