and to plan for production. While Convair struggled with aerodynamic issues, Lockheed pursued its own efforts on high-speed, high-altitude reconnaissance designs, evolving from A-4 through A-11. The first three configurations, A-4 through A-6, were smaller, self-launched aircraft with vertical surfaces hidden above the wing. The aircraft used a variety of propulsion schemes that included turbojets, ramjets, and rockets. None met the required mission radius of , leading Lockheed to conclude that maximum performance and low radar cross section were mutually exclusive. The A-10 and A-11 configurations were larger aircraft that also focused on performance at the expense of radar cross section. Lockheed submitted the more refined A-11 at the next Land Panel review. June 1959: The Land panel provisionally selects the A-11 over FISH, instructing both companies to re-design their aircraft. In July, the Land panel rejected both the Convair and Lockheed proposals. The Convair FISH used unproven ramjet engine technology and would be launched from a modified B-58B Hustler which was canceled in June. The susceptibility of the A-11 to radar detection was considered too great. On 20 August, both firms provided specifications for their revised proposals. 14 September 1959: CIA awards antiradar study, aerodynamic structural tests, and engineering designs, selecting the A-12 over rival Convair's Kingfish. Project Oxcart established. The A-12 design, a combination of their A-7 and A-11 submissions, emphasized low radar cross section, extremely high altitude and high-speed performance. Earlier, on 3 September, Project GUSTO was concluded and Project OXCART, to build the A-12, was begun. 26 January 1960: The CIA formally placed an order for 12 A-12 aircraft. 1 May 1960: Francis Gary Powers is shot down in a U-2 over the Soviet Union. He safely ejected and was turned over to Soviet authorities. A well-publicized trial followed and he was sentenced to 10 years "deprivation of liberty," serving three years in prison before being exchanged in 1962 for Soviet spy Rudolf Abel. Upon return he was debriefed extensively. 26 April 1962: First flight of A-12 with Lockheed test pilot Louis Schalk at Groom Lake. The previous day, it had made an unofficial and unannounced flight, in keeping with Lockheed tradition. Schalk flew the aircraft less than two miles (three km), at an altitude of about , because of serious wobbling caused by improper hookup of some navigational controls. Instead of circling around and landing, Schalk landed in the lake bed beyond the end of