A former parking lot attendant at the Smithsonian National Air and Space Museum annex in Chantilly pleaded guilty to stealing at least $400,000 in parking fees.

Freweyni Mebrahtu, 45, of Sterling, pleaded guilty to theft of public money Thursday in federal court in Alexandria. She is scheduled to be sentenced on Jan. 18 and faces up to 10 years in prison.

From March 2009 to July 2012, Mebrahtu worked as a booth attendant at the parking lot of the Steven F. Udvar-Hazy Center, an annex of the National Air and Space Museum that is home to the Space Shuttle Discovery and other aircraft.

Mebrahtu admitted that from about October 2009 to July 2012, she stole the $15 parking fees of thousands of museum visitors. She often unplugged the electronic vehicle counter in her booth, and she would not give customers serialized parking tickets to put in their cars as proof of purchase, according to court documents.

Mebrahtu is the second former Smithsonian parking lot attendant to plead guilty to stealing fees. In September, 36-year-old Meseret Terefe, of Silver Spring, also admitted to stealing at least $400,000.