Mercury Atlas 9 Spacecraft: S/C-19 Launch Vehicle: Atlas 130-D Scheduled Launch: 1 Jun 1962 Last Scheduled: 5 Dec 1961 Prime Crew	⇑ Mission List ⇑ Designation: Mercury A O-4 Description: 4th Mercury Atlas manned orbital
	L G Cooper Backup Crew A B Shepard

A fourth three-orbit mission appeared in program planning documents as late as December 1961 and was canceled some time thereafter due to delays 1n the launch schedule while progress had been made in modifying the Mercury spacecraft for 18-orbit missions. The program insignia shown above is post factum. References: Office of Manned Space Flight. 1961. "Long Range Plan, Part I: Spacecraft and Flight Missions." 5 December. HSI-16961. Encyclopedia Astronautica. Wikipedia.