After a smooth countdown, Atlas launch vehicle 5303 rose from pad 14 at 10:12 a.m. For two minutes the rocket's three engines rammed Agena 5004 skyward. Only ten seconds before the two outboard engines were supposed to stop, however, one of them gimbaled and locked in a hardover pitchdown position. The whole combination - Atlas and Agena - flipped over into a nosedive and headed like a runaway torpedo back toward Cape Kennedy.34
Shortly after the booster engines stopped firing, the guidance control officer reported he had lost touch with the launch vehicle. Richard W. Keehn, General Dynamics program manager for the Gemini Atlas, was alarmed and puzzled. Telemetry showed that the sustainer engine had cut off, and a signal that the Agena had separated from its launch vehicle followed. Agena signals kept coming until 456 seconds after launch - then there was silence. Keehn raced over to Hangar J, the General Dynamics data station, where the telemetry tapes pointed to an Atlas engine problem. But television reports implied that the target  vehicle was in trouble again, and Lockheed officials winced whenever they heard someone speak of the "Agena bird"; this was ironic in the light of the problems and delays caused by Atlas in the Mercury program and the success of Agena in Project Surefire and Gemini VIII. Meanwhile, the Gemini IX Atlas and Agena had plunged into the Atlantic Ocean 198 kilometers from where they had started.35
As contractors worried about technical problems, NASA again faced the necessity for a quick recovery plan when a target vehicle failed to reach orbit. This time, however, the agency had something in the hangar, an alternate vehicle - the ATDA. After the Agena exploded in October 1965, NASA had ordered General Dynamics/Convair to be prepared to furnish a backup Atlas within 14 days of another such catastrophe.36 And in April 1966, just a month before the attempted launch of Gemini IX, Schneider had reminded Preston that he would have to be ready to launch the alternate target in a hurry if the Agena again failed to keep its orbital appointment. Now it had. On 18 May, Mathews wired Colonel John Hudson, Deputy Commander for Launch Vehicles, Air Force Space Systems Division, to prepare Atlas 5304 for launch on 31 May in a mission now called Gemini IX-A.37
With what had been the backup plan now in effect, the next question was what to do if the ATDA, too, failed. At a staff meeting on 18 May, Mathews announced that Gemini IX-A would be launched anyway, to rendezvous with the Gemini VIII Agena, still in orbit. McDonnell, in any case, was confident of the ATDA. When Mathews asked, in a management meeting in St. Louis the next day, "Does anyone have any reservations about flying the ATDA?" the answer was no.38 That was just as well, because the motion of a rendezvous with the old Agena soon had to be abandoned. Its orbit had not decayed to the expected extent, and it was still sailing around Earth 402 kilometers up. Without the help of Agena, high-altitude flight might take too much spacecraft fuel and leave the crew stranded with no way to get to the lower orbit needed for retrofire.39 Deputy Administrator Robert Seamans and Mueller agreed with Mathews that rendezvous with Agena 8 was too risky, but Gemini IX-A would still fly, even if the substitute target did not make it. Extravehicular activity with the AMU was a much needed venture in its own right.40
Long before these decisions were made, the Atlas contractors were frantically busy. Keehn had bundled up the telemetry tapes and headed for San Diego, where study of the data plus some tests located the trouble in the electrical wiring.41 Within a week, Keehn and his group pinpointed the cause of the failure: a pinched wire in the autopilot that produced a short circuit. This meant some extra work on the electrical connectors, and General Dynamics asked NASA for an extra day to complete the task and prepare Atlas 5304 for launch. The agency set 1 June as the new date.42
 Although General Dynamics had accepted the blame for the mission failure, Lockheed was worried about telemetry signals that indicated a problem with an Agena inverter. A nagging question persisted. Could the target vehicle have gone into orbit if the Atlas had worked? This inverter provided power to both the gyroscope and the sequence timer. To Lockheed's relief, a series of row cameras located at Melbourne Beach, Florida, got pictures of the Atlas' outside loop. They showed that the Agena passed through ionized gases from the booster's exhaust, which caused an electrical short and failure of the inverter.43
On 1 June 1966, men and machines were again gathered at the Cape Kennedy launch site, this time to try to send the alternate target vehicle and Gemini IX-A into coordinated orbital flight. At the appointed time, 10:00 a.m., the Atlas rose from pad 14. After a six-minute boosted phase, it tossed the ATDA into a nearly perfect 298-kilometer orbit. Just one thing marred the picture: telemetry signals suggested that the launch shroud covering the docking port had only partially opened and had failed to jettison.
Concurrently, over on pad 19, Stafford and Cernan were going through their countdown to launch. When the count reached the three-minute mark, a hold was called so the spacecraft could be launched precisely on time for the best catchup trajectory with its target. Almost immediately after the count resumed, problems developed in the Cape ground launch control equipment when it tried to send the spacecraft refined information on the exact launch azimuth. The launch window (only 40 seconds long) closed, and Mission Director Schneider delayed the flight for 48 hours. For the second time, Stafford and Cernan had to take the elevator down. Stafford later said, "Frank [Borman] and Jim [Lovell] may have more flight time, but nobody had more pad time in Gemini than I did!" By the time Gemini IX-A lifted off, he had been in the two spacecraft (6 and 9) ready for launch a total of six times.44
33 Memo, Christopher C. Kraft, Jr., to dist., "Assignment of Flight Directors," 23 March 1966; "Houston Gemini News Center Accreditation List," Gemini IV, 11 June 1965; "Gemini News Center Accreditation List," Gemini IX-A, 1 June 1966; Anne Thompson, "On-the-Ground Teams: Blacks, Greens, Whites at Controls for Gemini-9," Houston Chronicle, 13 May 1966.
34 "Atlas SLV-3, Space Launch Vehicle Flight Evaluation Report, SL V-5303," General Dynamics GDC/BK F-66-029 and Supplemental Report No.6 to "Gemini IX-A Mission Report," 27 June 1966, p. 1-1; Flora Lewis, "Gemini 9 Postponed 3 Weeks," The Washington Post, 18 May 1966; Project Gemini Quarterly Status Report No. 17, for period ending 31 May 1966, p. 16.
35 Richard W. Keehn, interview, San Diego, 18 May 1967; Harold W. Nolan and Richard M. Spath, interview, Sunnyvale, Calif., 1 July 1966; Griffin, interview, Canoga Park, Calif., 16 May 1967; "Gemini 9 Mission, Public Information Operations," NASA/MSC working paper, 5 April 1966, p. 1; Evert Clark, "Failure of Agena Bars Gemini Trip," The New York Times, 18 May 1966; Meyer, notes on GPO staff meeting, 18 May 1966; "Gemini Agena Target Vehicle 5004 Systems Test Evaluation (45-Day Report)," LMSC-A819881 (Supplemental Report No. 7 to "Gemini IX-A Mission Report") 30 June 1966, p. x; letter, V. F. Peterson to AFSSD, Attn: Michael Aftanas, Jr., "LMSC Product Assurance and Reliability Program Plan for Project Sure Fire, Contract AF 04(695)-545, Gemini, S.A. 25," 29 April 1966, with enclosure; TWX, Mathews to SSD, Attn: Col. Alfred J. Gardner, GV-12395, 1 April 1966; "Project Sure Fire, GATV Engine Modification and Test Program: Final Report," SSD-545-66-10 (LMSC-A818110), 1 July 1966, 2 vols.; "GATV Design Certification Report for Gemini VIII Mission," LMSC-A794903, 26 Feb. 1966; letters, Mathews to Brig. Gen. Lee V. Gossick and W. H. Gisel, GV- 66384 and GV-66383, 19 April 1966; The Lockheed Star, Vol. XIII, No. 7 (1 April 1966); "Gemini Agena Target Vehicle 5004, NASA Mission Gemini IX Flight Safety Review at ETR," Aerospace TOR- 669(6183)-12, 16 May 1966; Swenson, Grimwood, and Alexander, This New Ocean, pp. 299-300, 335-37, 383, for example.
36 Meyer, notes on GPO staff meeting, 25 Jan. 1966, p. 3; TWXs, Mathews to SSD, Attn: Col. Billy J. McCarroll, GP-7506, 31 March, and GP-7544, 6 May 1966; TWX, Mgr., Manned Space Flight Support Ops. [Maj. Gen. Leighton I. Davis], Patrick AFB, Fla., to AIG 7106 [Address Indicator Grouping, which indicates distribution No. 7016, in this case about 50 addressees], DDMA 63161, 17 May 1966; Kathryn A. Lansdowne, telephone interview, 7 Aug. 1973; Meyer notes, 18 May 1966, p. 1; letter, Schneider to Preston, 11 April 1966.
37 TWX, Mathews to SSD, Attn: Col. John B. Hudson, GV-12434, 18 May 1966; TWX, Alibrando to MSC for Paul P. Haney and to KSC for John W. King and Gordon L. Harris, M-N-382, 19 May 1966.
38 Meyer notes, 18 May 1966, p. 1; Meyer, notes on NASA/MAC management meeting, 19 May 1966, p. 1.
39 Meyer, notes on GPO staff meeting, 26 April 1966, p. 2; memo, Mathews to dist., "Gemini IX Agena parking orbit," GV-66431, 13 May 1966; memo, Mathews to Dep. Dir., "Notes regarding reentry from orbit for proposed Gemini IX-A backup mission," GV-66447, 26 May 1966; TWX, Mathews to SSD, Attn: Col. Robert R. Hull, and McDonnell, Attn: Burke, "Gemini IX-A and Gemini IX-B (Backup Mission) Targeting Conditions," GV-12447,27 May 1966.
40 Memo, Robert C. Seamans, Jr., for record, "Selection of Gemini IX Mission Objectives," 31 May 1966.
41 Keehn interview.
42 Ibid.; "SLV-3, Flight Evaluation Report," pp. 2-1, -3; Dugald O. Black, telephone interview, 30 March 1970.
43 Nolan and Keehn interviews; Jerome B. Hammack, interview, Houston, 19 Aug1966; "Gemini Agena Target Vehicle 5004," pp. vii, viii, 3-12, 4-1.
44 "Gemini IX-A Mission Report," pp. 5-149, -150, -151; Gemini 9A News Center Releases Nos. 17, 18, and 19, I June 1966; "Gemini 9A Postponement Press Briefing," 1 June 1966; "Gemini 9A Pre-Mission Update Conference," 2 June 1966; Malik and Souris, Gemini Technical Summary, p. 343; [Ivan D. Ertel], Gemini IX-A: Rendezvous Mission, MSC Fact Sheet No. 291-F (Houston, August 1966); Lt. Col. Alexander C. Kuras and Col. John G. Albert, "Gemini-Titan Technical Summary," 24 Jan. 1967, pp. 147-48; Gemini-Titan II Air Force Launch Vehicle Press Handbook (Martin-Baltimore, Manned Space Flight, 2nd ed. rev.,1966), p. D-16; TWX, Edmond C. Buckley to Goddard, Attn: John F. Clark, to MSC, Attn: Gilruth, and Patrick AFB, Attn: Maj. Gen. Vincent G. Huston, "Guidance System Update Failure on GT-9 Mission," TD-7122, 3 June 1966; quote confirmed by telephone with Stafford, 26 July 1973.