Building a satellite swarm to investigate an atmospheric anomaly
Ideas Lab is a National Science Foundation initiative that aims to solve big scientific questions and advance the limits of technology using diverse research prospectives.
How does it work? In short, NSF brings together a group of 20-30 researchers who typically do not know each other and essentially puts them in a room for a week with the directive to work as a group to take on a science or engineering problem.
By the last day of the workshop, attendees were expected to have a general research plan and funding proposal to submit to NSF.
“At the end of the workshop, seven project ideas were pitched to NSF. They invited four to submit full proposals and ultimately selected two, including SWARM-EX,” Palo said.
The concept of Ideas Lab originated in England, where the Engineering and Physical Sciences Research Council, a British equivalent of the United States-based National Science Foundation, sent out a standard request for research funding proposals.
They felt the responses were not ambitious enough, and developed what they called a “sandpit” workshop in response.
The goal is that by bringing researchers from diverse subject areas together, they will share ideas, interact and argue, and think of new solutions to problems no one researcher would come up with on their own.
Scott Palo is leading a multi-university effort to unlock a scientific mystery in near-Earth space.
He is leading a team that has earned a $4 million, four-year grant from the National Science Foundation's Ideas Lab to design and build three CubeSat nanosatellites to investigate the relationship between charged particles and neutral particles in the thermosphere, an area that extends from 95 km – 600 km (50 miles - 375 miles) above Earth's surface and includes the orbits of many satellites and the International Space Station.
The project is called SWARM-EX, or Space Weather Atmospheric Reconfigurable Multiscale Experiment. The phenomenon to be studied is known as the equatorial ionization anomaly and equatorial thermosphere anomaly.
“Their formation and behavior are not well-determined. There are competing theories, and we want to make measurements to fundamentally understand how they are related,” said Palo, the principal investigator on the project and a professor in the Ann and H.J. Smead Department of Aerospace Engineering Sciences at the University of Colorado Boulder.
Renderings of the SWARM-EX CubeSat.
Working with Palo at CU Boulder is Jeff Thayer, an aerospace professor who has done theoretical modeling of the anomalies in the past and is eager to see the results of real-world measurements.
“Understanding these anomalies is important for societal reasons. They negatively impact GPS and communications satellites, and the neutral particles cause drag on spacecraft and orbital debris,” Thayer said.
The CubeSats are small – just slightly larger than a loaf of bread – but do not let their size fool you. Advances in technology have made it possible to pack a strong scientific punch in even the smallest spaces. Each CubeSat will carry two scientific instruments in addition to communications equipment, batteries, solar cells and fuel.
CU Boulder is one of six universities working on the project, along with the Georgia Institute of Technology, Olin College, Stanford University, University of South Alabama and Western Michigan University.
By building and flying three satellites, the team hopes to better understand the development of the anomalies.
“The plasma is unstable and changes quickly. Typically, you only have one satellite, and it passes over an area every 90 minutes, but we know these processes happen faster than that. With a constellation of three CubeSats, we’ll have control over their distances and be able to see the evolution of the particles,” Thayer said.
The goal of the CubeSats is twofold, with research as only one part of the overall mission. The second objective is to push the limits of CubeSat technology by incorporating propulsion and autonomous systems so the satellites can communicate with each other to coordinate movements and adapt to changing conditions automatically.
“SWARM-EX will demonstrate how we can fly these small sensor platforms in various configurations and that the resulting instrument-formation is more than the sum of its parts,” said Marcin Pilinski, a research associate at the Laboratory for Atmospheric and Space Physics at CU Boulder and the instrument lead on SWARM-EX.
Onboard propulsion is not typically part of small satellites due to the complexity it adds, and autonomous navigation algorithms are new enough to be novel in any satellite. The team is incorporating both in an intentional effort to advance the limits of technology in small satellites. Funding big, new concepts is a deliberate goal of the NSF Ideas Lab program.
“They tell you to push the envelope,” Palo said. “They’re looking for things that haven’t been done before.”
Each university involved in the project has a different role:
- CU Boulder: Command and data handling, software, spacecraft assembly and integration, principal investigator, science lead
- Georgia Tech: Propulsion
- Olin College: Mechanical design, systems engineering and operations
- Stanford: Autonomous navigation systems
- South Alabama: Communication systems
- Western Michigan: Systems design for propulsion integration
The grant officially begins January 1, with launch expected during the third year of the project. The satellites’ orbital mission should last for six to 12 months after that.
The timeline is a unique feature of CubeSat projects. Unlike large communications or research satellites that can take 10 or more years and well over $100 million to build, CubeSats can go from concept to completion in just a few years, allowing college students to see all parts of the process before graduating.
“The technology and the science are both exciting,” Palo said. “But we also have students involved in ways they never could be before.”