Dyna Soar 4 Spacecraft: (no serial number) Launch Vehicle: Titan II Scheduled Launch: 1 Jun 1965 Last Scheduled: 14 Sep 1961	⇑ Mission List ⇑ Designation: Dyna-Soar T2 S-2 Description: 2nd Dyna-Soar Titan II manned suborbital
	not assigned Backup Crew not assigned

Because of the increasing design weight of the Dyna-Soar spacecraft, in February 1961 the program switched from the Titan I launch vehicle to the more powerful Titan II for suborbital missions. The Air Force canceled the suborbital flights on 16 October 1961, and the program was redirected to all orbital missions. On the last schedule before the cancellation, the first manned suborbital flight would have been set for June 1965, assuming two-month launch centers. Although the Dyna-Soar manned suborbital program was terminated before the Air Force assigned astronauts to specific flights, it did select a group of test pilots for Dyna-Soar in April 1960: Neil A. Armstrong William H. Dana Henry C. Gordon William J. Knight Russell L. Rogers Milton O. Thompson James W. Wood The Air Force had previously selected Neil A. Armstrong in 1958 for its Man In Space Soonest program. NASA selected him in Group 2 on 17 September 1962. The Dyna-Soar program insignia shown above depicts the spacecraft on a Titan II. References: USAF. 1960. "Dyna Soar Characteristics Summaries." September. Geiger, Clarence J. 1963. "History of the X-20A Dyna-Soar." Vol. 1. Aeronautical Systems Division, Wright-Patterson AFB, Ohio, p. 68. Godwin, Robert, ed. 2003 Dyna-Soar: Hypersonic Strategic Weapons System." Apogee Books Space Series 35 Paperback, p. 50. Strom, Steven R. 2004. "Jurassic Technology: The History of the Dyna-Soar." Crosslink, Winter, pp. 6-9. Aerospace Corporation. Encyclopedia Astronautica. Wikipedia.

N A Armstrong W H Dana H C Gordon W J Knight R L Rogers M O Thompson J W Wood