While based at Sanford, a fellow officer of Mattingly's was assigned to a undertake aerial photo reconnaissance of a launch from Cape Canaveral and convinced Mattingly to accompany him on this mission, where they observed the launch of Gemini 3 (carrying Mattingly's future Apollo 16 Commander John Young) from the air. After finishing his second cruise, Mattingly was frustrated in his attempt to join the Naval test pilot school at Patuxent River since his cruise ended after the start of the class. However, he managed to obtain a place in the Air Force test pilot school at Edwards Air Force Base in California where future astronauts Edgar Mitchell and Karol J. Bobko were his classmates and his instructors included Charles Duke, his Apollo 16 crewmate, and Henry Hartsfield, who Mattingly would command on STS 4.