Emerging small sats could complicate spectrum

Federal agencies ranging from the Federal Communications Commission to the National Institute of Standards and Technology are pushing advances in small satellite technologies, but there is a downside for spectrum holders, according to experts.

Small satellite technology is a revolution the FCC can't ignore, Chairman Ajit Pai told a group of satellite industry executives at a U.S. Chamber of Commerce event on July 9. Small satellites under 400 lbs. and even constellations of satellites can be more agilely developed and launched, thanks to the efforts of private space companies such as Jeff Bezos' Blue Origin, Richard Branson's Virgin Launch, Elon Musk's SpaceX and others. The systems are also relatively short-lived, lasting up to six years before their orbits deteriorate and they're replaced.

These small satellites can expand broadband access via high-capacity links to remote areas that can't be served with wire or wireless broadband links, Pai said.

In early July, Amazon filed an application with the FCC to launch up to 3,200 small satellites for its "Kuiper System" that would eventually provide broadband connections around the world.

"Smallsats are currently used for everything from communications to remote sensing to scientific research. There are a lot of startups working to make small sat technology a real player in the digital communications revolution," said Pai.

Pai aims to help small satellite efforts along. He announced at the event that he had moved to set up a faster, less cumbersome FCC application process for satellites under 400 pounds, with a lower application fee and a shorter review timeline. The proposed rule, he said, offers potential radiofrequency interference protection for critical communication links and would promote more efficient spectrum use.

The FCC licenses satellite operators' radio frequency communications, which is required to control the spacecraft.

"I see no reason why a satellite the size of a shoebox, with the life expectancy of a guinea pig, should be regulated the same way as a spacecraft the size of a school bus that will stay in orbit for centuries," he told the audience.

The proposed rulemaking is up for a vote at the commission on Aug. 1, Pai said.

Even though the technology offers a new frontier for commercial companies, it could impact other spectrum users as smallsat's primary applications change, according to one expert at the Chamber of Commerce event.

Small satellite constellation applications are about to undergo a dramatic shift, said Bhavya Lal, research staff member at the Institute for Defense Analysis, that could cramp spectrum resources.

"Up until now 80%" of small satellite applications have been for remote sensing, she said, and only 10% for communications applications. "There is an inversion coming," she said, in which those statistics will flip, with 80% of applications focused on communications applications and 10% on sensing.

"That will have huge implications for RFI [radio frequency interference] and spectrum," Lal said. Spectrum allocation will have to be more closely coordinated among commercial providers, government and other spectrum users in that environment, she predicted.

The technology is entering an already-complex spectrum environment.

Federal spectrum holders, such as the Defense Department and the National Oceanic and Atmospheric Administration, have concerns over spectrum allocations to commercial providers. Most recently NOAA and NASA complained to the FCC that its plans for 5G spectrum would interfere with weather satellite transmissions.

Matt Scholl, chief of computer security at NIST, said the small satellite technology is also emerging at a sensitive time in cybersecurity. Space vehicles should obviously incorporate cybersecurity measures to prevent attacks, but Scholl urged small satellite technology developers to look beyond today's cybersecurity algorithms to next-generation protections that take emerging quantum computing technologies into account.

"I'd be cautious about hardwiring encryption into silicon" chips on satellites, he said. Today's cipher and key management for cybersecurity is going obsolete by 2025, as quantum computing comes online.
"Cryptographic agility is critical for small satellite security," he said. However, citing the vehicles' small size and location, he likened protecting the space vehicles to protecting internet-of-things devices. He said "lightweight encryption" capabilities are more practical onboard small, relatively low-powered satellites than the large, heavy, keyboard-based encryption capabilities used on terrestrial systems.