Nowak was arrested on Monday while attempting to confront a woman she believed was a rival for the affections of William Oefelein, a space shuttle pilot who flew on a mission in December last year.
Police said Nowak drove from her home in Houston to the Orlando International airport to confront Colleen Shipman, who she believed was her rival.
Nowak drove to Orlando international airport, disguised herself in a wig and trench coat and followed Shipman to her car in a parking lot, according to the arrest affidavit.
Shipman told police that she noticed someone following her, hurried inside the car and locked the doors.
Nowak tried to open the car door and asked for a ride. Shipman refused but rolled down the car window a few inches when Nowak started crying.
|William Oefelein is a space shuttle pilot [EPA]|
Nowak then sprayed a chemical into Shipman's car, the affidavit said.
During a check of the car park, an officer followed Nowak and watched her throw away a bag containing the wig and air rifle.
When Nowak was arrested, police also found a steel mallet, a 10cm folding knife, rubber tubing, $600 and garbage bags inside a bag she was carrying, authorities said.
Police later searched Nowak's car and found a letter "that indicated how much Mrs Nowak loved Mr Oefelein", emails from Shipman to Oefelein, directions to Shipman's house and receipts indicating Nowak paid only in cash during her trip from Houston, including for her hotel stay.
Nowak had originally been charged with attempted kidnapping, but prosecutors up graded the charge to attempted murder, basing it on the weapons and other items that were said to have been found with Nowak or in her car.
Police also said they had found nappies that Nowak told them she wore during her drive from Houston to Orlando so she would not have to stop to urinate.
Police question Nowak
Nowak told police that her relationship with Oefelein was "more than a working relationship but less than a romantic relationship", according to an arrest affidavit.
In her statement to police, Nowak said she did not intend to physically harm Shipman, but "only wanted to scare Ms Shipman into talking with her".
Police recommended Nowak be held without bail because of the detailed planning, disguises and weapons found in her possession.
Sgt Barbara Jones, a spokeswoman for the Orlando police department, said: "If you were just going to talk to someone, I don't know that you would need a wig, a trench coat, an air cartridge BB gun and pepper spray."
According to Nasa's official biography, Nowak is married with three children.
During her 13-day mission in July she operated the robotic arm during three spacewalks.
Oefelein is unmarried. He piloted the space shuttle Discovery in December. He has two children, according to a Nasa biography.
Nowak and Oefelein were both first-time fliers during their shuttle missions last year and although they trained together, they never flew together.