The ambitious goal of Elon Musk’s Starlink and other satellite internet projects is to provide high-speed, low-latency broadband internet worldwide. But there are still some big questions that need to be answered – including how to build a resilient, secure network in space.
To investigate such questions, Commonwealth Cyber Initiative (CCI) researchers at Virginia Tech have teamed up with the University of Surrey in the UK to build the world’s first hardware-in-the-loop testbed, which will test the changing connectivity of a megasatellite constellation emulated on a scale. The researchers presented the test bed at an intercontinental workshop on July 12-13.
“We wanted to establish a shared community vision and brainstorm what would be possible and most useful in a space network infrastructure,” said CCI researcher Jonathan Black, professor of aerospace engineering.
The interdisciplinary workshop not only brought together researchers and funding agencies from both sides of the Atlantic, but also included members of the satellite and aerospace community, as well as the computer networking and communications communities, including researchers from Wireless@VT in the Bradley Department of Electrical and Computer Engineering and the Center for Space Science and Engineering Research (Space@VT).
Workshop speakers included representatives from NASA Goddard Space Flight Center and the National Science Foundation, as well as Ella Atkins, Fred D. Durham Chair and new department head of the Kevin T. Crofton Department of Aerospace and Ocean Engineering.
“To repair, upgrade, and refuel in space, we must rely on efficiency and disruption,” said Atkins, who called into the workshop via Starlink from her rural home. “By grounding communications and connectivity in long-term space robotics, our researchers are shaping the future of space engineering.”
According to Atkins and Black, the future of space technology requires effective communications – and the next step is connecting satellite networks.
Breaking out of space silos
On the ground, network providers of internet services are connected to each other. For example, a user on the Verizon network can talk to someone on an AT&T network. Communication jumps between networks.
However, in space, communications are isolated. The mega-constellations of satellites that comprise different space networks do not communicate with each other – not between orbits, not between networks and not between individual satellites.
“We want all networks to be able to communicate securely and efficiently,” said Black, who also serves as director of the Aerospace and Ocean Systems Division at the National Security Institute and co-director of the Center for Space Science and Engineering Research. “The workshop and test stand are both directly involved in making this happen – connecting the various space networks in constellations and aligning with 5g/NextG wireless communication capabilities.”
Test interconnectivity, build resilience
With support from the Commonwealth Cyber Initiative, the Virginia Tech team and its partners have been exploring new high-bandwidth space-based networks. The testbed they developed over the past year will simulate mega internet constellations, including satellites, ground stations, connected devices like phones, and the connections between them all.
“We have on the order of thousands of spacecraft being simulated as nodes,” said Samantha Parry Kenyon, research associate at Space@VT and co-principal investigator on the CCI project. “We can physically communicate with hardware nodes and plug them directly into the virtual satellite nodes from the simulation.”
By running the testbed through different scenarios, the team examines what to do when operations are disrupted by something like a space event or a security breach, and how a neighboring satellite network might compensate for a compromised system.
Resilience is about how a system responds to unexpected changes, Black explained. “The network must be able to continue to function even if it is impaired.”
With help from the Virginia Tech Integrated Security Education and Research Center, the team plans to open up the testbed reference architecture and allow other Commonwealth Cyber Initiative institutions, researchers, educators, and students to explore and optimize pathways to constellation between constellations .
With the ability to model Starlink-scale constellations, researchers will be able to design resilient, secure, and interconnected networks—both hardware and software.