But it's causing not just national security and diplomatic concerns for the Biden administration, but also a political headache.
Republicans aren't the only ones criticizing Biden's handling of the situation. Montana Sen. Jon Tester, one of the most vulnerable Democrats up for re-election in 2024, demanded "real answers" after the balloon drifted over his state.
Tester, who heads the Senate subcommittee that oversees defense spending, said he will be pulling administration officials before his panel.
"Montanans value their freedom and privacy, and I'll always fight to defend both," he tweeted.
Incursions by spy balloons into U.S. airspace have occurred before, Air Force Brig. Gen. Pat Ryder told reporters Friday. But he declined to list instances.
“What I would tell you right now is that information is classified,” Ryder said. “I'm not able to provide it other than I can confirm that there have been other incidents where balloons did come close to or cross over U.S. territory.”