The plane "was within sight of the launch pad," said NASA spokesman George Diller.
The restricted air space is about 10 miles by 30 miles and is clearly marked on air charts, Diller said. Since the Sept. 11 terrorist attacks, pilots have not been allowed within the area at any time.
"He clearly should have known," Diller said.
A sheriff's office helicopter from Volusia County escorted the plane down to the Ormond Beach Municipal Airport, where it was searched for explosives and drugs, said sheriff's spokesman Gary Davidson. Nothing suspicious was detected, he said.
The pilot was not immediately identified. He was being interviewed by FBI agents and had not been taken into custody by midday, Davidson said.