As a computer scientist and cybersecurity expert who studies real-time systems, Linh Thi Xuan Phan of the School of Engineering and Applied Science knows that some of the most consequential threats are invisible and detected when it’s too late.

“A cybersecurity attack can take many forms,” says Phan, whose work helped expose a flaw in the network technology aboard NASA’s Orion capsule. “The most consequential attack may have very little to do with stealing information.”

In recognition of Cybersecurity Awareness Month in October, Phan explains why spacecraft are so hard to defend, why a few milliseconds can matter, and how AI might change the cybersecurity landscape.

No house calls in orbit
Whatever form an attack takes, the fallout could result in the spacecraft losing “the ability to communicate, misinterpret its orientation, point an antenna in the wrong direction, or fail to execute a maneuver correctly,” Phan says.

Repairs are harder, too.

“One of the most obvious challenges is that you can’t go fix it,” she says. “If something goes wrong with a bank’s server, you can send an engineer into the room.”

Even the defenses can backfire. “A sophisticated security monitor might be extremely accurate, but if it occasionally takes too long to execute, another task could miss its deadline,” she says. “The security mechanism then becomes a problem in its own right.”

Read more at Penn Today.