In civilian criminal proceedings, Nowak was sentenced in November to a year's probation and two days jail time, already served, for attacking Capt. Colleen Shipman at the Orlando (Fla.) International Airport in February 2007.
Now, the Naval Criminal Investigative Service is investigating military punishment for Nowak, a Navy captain, Florida Today reported Monday.
The most severe punishment includes imprisonment, dismissal from the Navy or loss of pension.
Nowak drove from Houston to Orlando to confront Shipman about their mutual love interest, former astronaut William Oefelein.
Nowak pepper-sprayed Shipman in an airport parking lot. Nowak's car contained a BB pistol, a hunting knife, a rubber mallet, rubber tubing, garbage bags and maps to Shipman's home.
An attempted murder charge against Nowak was dropped and Nowak since has apologized to Shipman.
Shipman and Oefelein have retired from the military, live in Alaska and are engaged to be married. Nowak is stationed at Naval Air Station Corpus Christi as a flight trainer.