Space Shuttle Discovery at the Udvar-Hazy Center in Chantilly, Va. (Photo by Dan Dan the Binary Man)

Federal prosecutors in Virginia are charging three parking attendants at a parking lot attached to the Smithsonian’s Udvar-Hazy Center near Dulles International Airport of stealing more than $400,000 from machines that tally the flow of customers driving in and out.

The Washington Post reports that the attendants—Meseret Terefe, Genete Yigzu and Freweyni Mebrahtu—are accused of unplugging the machines that count visitors’ cars and ripping off thousands of the $15 fees that people pay to park at the museum. The Udvar-Hazy Center is an annex of the National Air and Space Museum, and houses many of the great vessels in aeronautical history, including the Space Shuttle Discovery and Enola Gay, the B-29 bomber that dropped the atomic bomb on Hiroshima, Japan in 1945.

What Terefe, Yigzu and Mebrahtu are accused of, however, is not nearly as high-flying as those engineering feats. According to court documents filed in the Eastern District of Virginia, the pair started stealing from the parking meters shortly after their employer, Parking Management Inc., received a contract to operate the parking lot in April 2009.

“During a time of challenging budgets, the alleged theft of hundreds of thousands of dollars from the Smithsonian, a revered American institution, is extremely troubling,” Neil H. MacBride, the U.S. attorney for the Eastern District of Virginia, told the Post. If convicted of stealing from the Smithsonian, Terefe and Mebrahtu face up to 10 years in federal prison.

Prosecutors were tipped off by an informant in October 2011, and Terefe’s purchase of a 2012 Toyota Rav4 aroused further suspicion. (If the allegations pan out, Terefe would also be guilty of not heeding the lesson left by Lufthansa heist conspirator Louis Cafora.)

But authorities say Terefe, Yigzu and Mebrahtu stole as much as $4,000 a day from the Udvar-Hazy Center, which received 1.2 million visitors last year.

Theft from machines that serve transportation infrastructure is nothing new, though. In March, two former Washington Metropolitan Area Transit Authority employees pleaded guilty to stealing $445,000 from fare machines across the Metrorail system.