Agena Target Vehicle
Agena Target Docking Vehicle
Credit: © Mark Wade
Status: Operational 1965. First Launch: 1965-10-25. Last Launch: 1966-11-11. Number: 6 . Gross mass: 3,260 kg (7,180 lb). Height: 7.93 m (26.01 ft). Diameter: 1.52 m (4.98 ft).
To provide the Gemini spacecraft with a rendezvous and docking target, Agena D rocket stages were modified with the addition of a docking collar, status panel display, and restart capabilities for the Gemini program. After docking, the Agena had sufficient fuel reserves to boost the Gemini into high earth orbits, to the edge of the Van Allen radiation belts.
The Gemini-Agena Target Vehicle design was an adaptation of the basic Agena-D vehicle using the alternate Model 8247 rocket engine and additional program-peculiar equipment required for the Gemini mission. This GATV was divided into:
The Gemini-ATV propulsion system consisted of the following:
The propulsion system was designed to inject the GATV into an orbital path which has an altitude varying between 161 nautical miles (nm) and 87 nm when measured at a latitude of 28. 34 deg. A minimum of five main-engine burns were available to complete the mission requirements; one burn was required for injection into orbit and four subsequent burns were available to perform orbital plane and phase changes, as required and selected from ground stations or from the spacecraft. All launches took place from AMR Pad 14.
Once the GATV was in orbit, the PPS provided the thrust necessary for the following maneuvers :
The Gemini-ATV Status Panel (ASP), was mounted on the forward end of the Target Docking Adapter of the Agena Target Vehicle where it was visible to the astronauts in the Gemini spacecraft during and after the docking maneuver. The panel displayed information on the status and safety of the Agena propulsion, guidance, electrical power, and docking systems. Originally, only eight Agena parameters were to be displayed in the Gemini spacecraft; however, the number of parameters increased to the point that the spacecraft no longer had the space or weight capability to accommodate them. Accordingly, the panel was placed on the Target Docking Adapter. The ASP system consisted of a display panel with nine display lights and three analog dials and the necessary circuitry which was distributed throughout the Gemini-ATV. When not in use, this system was normally de-energized in order to save power; however, the PPS and SPS Time Remaining Clocks were energized whenever the PPS or SPS engines fire. Three of the twelve parameters displayed on the ASP panel, indicated PPS status and three indicated SPS status. The Primary Propulsion System displays were as follows:
Gemini docked to Agena
Credit: © Mark Wade
|Gemini 10 Agena Targ|
Credit: Manufacturer Image
Westinghouse Electric Corporation, Baltimore, Maryland, received a $6.8 million subcontract from McDonnell to provide the rendezvous radar and transponder system for the Gemini spacecraft. Purpose of the rendezvous radar, sited in the recovery section of the spacecraft, was to locate and track the target vehicle during rendezvous maneuvers. The transponder, a combined receiver and transmitter designed to transmit signals automatically when triggered by an interrogating signal, was located in the Agena target vehicle.
Marshall Space Flight Center delivered an Agena procurement schedule (dated March 8) to Gemini Project Office. Air Force Space Systems Division (SSD) was to contract with Lockheed for 11 target vehicles. SSD assigned the Gemini Agena target vehicle program to its Ranger Launch Directorate, which was responsible for programs using Agena vehicles. Marshall also reported the expected delivery of a qualified multiple-restart main engine in 50 weeks, an improvement that removed this development requirement as the pacing item in Agena scheduling.
Unlike the first, it considered launch vehicles as well as the spacecraft. Procurement of the Agena target vehicle had been initiated so recently that scope for analysis in that area was limited. A key feature of engineering development for the Gemini program was the use of a number of test articles, the lack of which had sometimes delayed the Mercury program; although constructing these test articles might cause some initial delay in Gemini spacecraft construction, the data they would provide would more than compensate for any delay. No problems beset launch vehicle development, but the schedule allowed little contingency time for unexpected problems. The first unmanned qualification flight was still scheduled for late July or early August 1963, but the second (manned) flight was now planned for late October or early November 1963 and the first Agena flight for late April or early Many 1964, with remaining flights to follow at two-month intervals, ending in mid-1965. Flight missions remained unchanged from the January analysis.
Air Force Space Systems Division (SSD) awarded a letter contract to Lockheed Missiles and Space Company for eight Agena vehicles to be modified as Gemini Agena target vehicles (GATV). Mission requirements were to (1) establish a circular orbit within specified limits, (2) provide a stable target with which the spacecraft could rendezvous and dock, (3) respond to commands from either ground stations or the spacecraft, (4) perform a complex series of orbital maneuvers by means of either real-time or stored commands if less than optimum launch of Agena or spacecraft occurred, and (5) provide an active orbit life of five days. Lockheed's analysis of these mission requirements provided the design criteria for the major modifications required to adapt the Agena to the Gemini mission: (1) modification of the primary propulsion system; (2) addition of a secondary propulsion system (two 16-pound and two 200-pound thrusters) to provide ullage orientation and minor orbit adjustments; (3) design of a digital command and communications subsystem including a programmer, controller, pulse-code-modulated telemetry system, and onboard tape recorder; (4) design of changes to provide the guidance and control functions peculiar to the GATV; and (5) addition of an auxiliary forward equipment rack with an interface capable of supporting the target docking adapter. On direction from Air Force Systems Command Headquarters, SSD authorized Lockheed to proceed with the Gemini-Agena program on March 19.
A preliminary design criteria review conference for complex 14, held in Los Angeles, resulted in ground rules for all contractors. Target dates established were (1) stand availability, July 1, 1963; (2) estimated beneficial occupancy date, November 1, 1963; and (3) vehicle on-stand date, February 1, 1964. Complex 14 would be used for launching the Gemini-Agena target vehicle and Mariner spacecraft, but basic modifications would be primarily for the Gemini program. On November 15, 1962, Air Force Space Systems Division reviewed the criteria summary report for complex 14 modifications and suggested only minor engineering changes.
James E Webb, Administrator of NASA, and Robert S McNamara, Secretary of Defense, concluded a major policy agreement defining the roles of NASA and Department of Defense (DOD) in Project Gemini. The agreement provided for the establishment of a joint NASA-DOD Gemini Program Planning Board. The board would plan experiments, conduct flight tests, and analyze and disseminate results. NASA would continue to manage Project Gemini, while DOD would take part in Gemini development, pilot training, preflight checkout, launch, and flight operations, and would be specifically responsible for the Titan II launch vehicle and the Atlas-Agena target vehicle. DOD would also contribute funds toward the attainment of Gemini objectives.
Representatives of Air Force Space Systems Division (SSD), Manned Spacecraft Center, and Lockheed met in Sunnyvale for the first management review of the Gemini Agena target vehicle (GATV). Patterned after similar meetings regularly held between SSD, Lewis Research Center, and Lockheed on medium space vehicle satellite and probe programs, the Gemini Target Management Review Meetings encompassed a comprehensive monthly review of the status of the GATV program.
As part of the general revision of the Gemini flight program that NASA Headquarters had approved April 29, representatives of NASA, Air Force Space Systems Division, and Lockheed met to establish basic ground rules for revising Agena development and delivery schedules. The first rendezvous mission using the Agena target vehicle was now planned for April 1965, some seven and one half months later than had been anticipated in October 1962. Six months would separate the second Agena launch from the first, and subsequent flights would be at three-month, rather than two-month, intervals. The revised schedule was agreed on at the Atlas/Agena coordination meeting on June 6-7, 1963. Among the major features of the new schedule: Agena communications and control subsystem development was to be completed by December 1963 (back six weeks); other Lockheed development work was to be completed by January 1964 (back three and one-half months); assembly and modification of the first target vehicle was to start April 2, 1964, with the vehicle to be accepted and delivered in January 1965; the first Atlas target launch vehicle was to be delivered in December 1964; the schedule for component manufacturing and deliveries was to be so arranged that the second target vehicle could back up the first, given about nine months' notice.
The Cape Gemini/Agena Test Integration Working Group met to define "Plan X" test procedures and responsibilities. The purpose of Plan X was to verify the Gemini spacecraft's ability to command the Agena target vehicle both by radio and hardline; to exercise all command, data, and communication links between the spacecraft, target vehicle, and mission control in all practical combinations, first with the two vehicles about six feet apart, then with the vehicles docked and latched but not rigidized; and to familiarize the astronauts with operating the spacecraft/target vehicle combination in a simulated rendezvous mission. Site of the test was to be the Merritt Island Launch Area Radar Range Boresight Tower ('Timber Tower'), a 65 x 25 x 50-foot wooden structure.
Development tests of the Agena Model 8247 main engine at Arnold Engineering Development Center ended when the latch-type gas generator valve failed in testing, making an emergency shutdown of the engine necessary. The wrong choice of emergency shutdown procedures caused turbine overspeed and total failure of the engine's turbine pump assembly. As a result of this failure, the valve was redesigned. Because success of the new design was doubtful, a parallel program was initiated to design and develop an alternative valve configuration, solenoid-operated rather than latch-type. Intensive development testing followed; and in a meeting at Bell Aerosystems on November 15, the solenoid type was selected for use in the first flight system of the Agena target vehicle. The new valve allowed significant reductions in engine complexity and increased reliability, but the development effort imposed a serious delay in Preliminary Flight Rating Tests, which had been scheduled to begin in September 1963.
As a result of the seven-and-one-half-month relaxation of the required launch date for the first GATV, Lockheed was directed to use the improved version of the standard Agena, the AD-62 block of vehicles, instead of AD-13. The AD-62 block originally included the multistart engine, subsequently slipped to the AD-71 block. Lockheed accordingly was directed in January 1964 to substitute the AD-71 for AD-62. The combined effect of these changes was to use up much of the seven-and-one-half-month leeway. The change to AD-62 caused a two-month slip, and changing to AD-71 added a five-week slip. With much of the contingency time gone, the Agena schedule was now tight, and further slippage threatened to cause launch delays.
Lockheed included a milestone schedule for the Gemini Agena target vehicle (GATV) in its monthly progress report for the first time since January 1963. The new schedule reflected the revised Gemini flight program of April 29 and the corresponding revision of the Agena program which followed. It displayed key events in the progress of the first GATV taking place between five and six months later than the January schedule. Engineering development was now scheduled to be completed by May 15, 1964, rather than by December 11, 1963. Completion of modification and final assembly was now planned for June 12 rather than January 10, 1964; preliminary vehicle systems testing was rescheduled from April 10 to September 11, 1964. Special tests, including a Radio frequency Interference Test in the later schedule in addition to the hot-firing scheduled earlier, were to end November 20 instead of May 22, 1964. Final Vehicle Systems Tests were to be completed December 18 instead of June 19, 1964, with shipment to follow on January 6, 1965, rather than June 30, 1964. Launch was now expected on April 15, 1965, seven and one-half months later than the September 1, 1964, date that had been planned in January 1963.
Douglas Aircraft Corporation, Tulsa, Oklahoma, began a series of tests to demonstrate the structural integrity of the Gemini target docking adapter (TDA) during shroud separation. The shroud, which protected the TDA during the launch and ascent of the Agena target vehicle, was tested under simulated altitude conditions to show proper operation of pyrotechnic devices and adequate clearance between shroud and TDA during separation. Successfully concluded on November 21, and tests demonstrated the compatibility of the TDA with the shroud system during operational performance, with no indication of damage or failure of the TDA structure.
Manned Spacecraft Center (MSC) approved Air Force Space Systems Division's (SSD) recommendations for a test program to increase confidence in 16 critical electronic and electrical components of the Gemini Agena target vehicle. The program included complete electromagnetic interference (EMI) testing of all components peculiar to the Gemini mission, as well as elevated stress tests and extended life tests. SSD had also recommended subsystem-level, as well as component-level, EMI testing, but this part of the program MSC disapproved. SSD directed Lockheed to proceed with the program on March 23. EMI tests were scheduled to be completed by July 1, stress and life tests by September 1, 1964.
Air Force Space Systems Division (SSD) accepted the first Agena D (AD-71) for the Gemini program. The Agena D was a production-line vehicle procured from Lockheed by SSD for NASA through routine procedures. Following minor retrofit operations, the vehicle, now designated Gemini Agena target vehicle 5001, entered the manufacturing final assembly area at the Lockheed plant on May 14. There began the conversion of the Agena D into a target vehicle for Gemini rendezvous missions. Major modifications were installation of a target docking adapter (supplied by McDonnell), an auxiliary equipment rack, external status displays, a secondary propulsion system, and an L-band tracking radar.
Lockheed inaugurated the Gemini Extra Care Program to reduce the incidence of equipment failures and discrepancies. In cooperation with Air Force and NASA, Lockheed inaugurated the Gemini Extra Care Program to reduce the incidence of equipment failures and discrepancies resulting from poor or careless workmanship during the modification and assembly of the Agena target vehicle. The program included increased inspection, exhortation, morale boosters, special awards, and other activities aimed at fostering and maintaining a strong team spirit at all levels. Results of the program were evidenced in a drastic decline in the number of FEDRs (Failed Equipment and Discrepancy Reports) recorded in the Gemini final manufacturing area on successive vehicles.
Lockheed completed the modification and final assembly of Gemini Agena target vehicle 5001 and transferred it to systems test complex C-10 at the Lockheed plant. Lockheed began the task of hooking the vehicle up for systems testing the next day, September 25.
Gemini Agena target vehicle (GATV) 5001 competed a simulated flight (ascent and orbit) at Lockheed test complex C-10. Minor anomalies required portions of the test to be rerun. This concluded GATV 5001 systems tests in preparation for captive-firing tests to be conducted at Lockheed's Santa Cruz Test Base. The vehicle was shipped November 30.
Lockheed shipped Gemini Agena target vehicle (GATV) 5001 to its Santa Cruz Test Base for captive-firing tests. Primary test objective was verifying the operational capabilities of the GATV during actual firing of the primary and secondary propulsion systems. Additional Details: here....
Gemini Agena target vehicle 5001 underwent a successful hot-firing test at Lockheed's Santa Cruz Test Base. The test simulated a full 20,000-second mission, including multiple firings of both the primary and secondary propulsion systems and transmission of operational data in real time to two PCM (pulse-code-modulated) telemetry ground stations, one at the test site and one in Sunnyvale. Major test anomaly was a series of command programmer time-accumulator jumps, seven of which totaled 77,899 seconds. The vehicle was removed from the test stand on February 1 and returned to Sunnyvale.
Gemini Agena target vehicle (GATV) 5001 was removed from the test stand at Santa Cruz Test Base and returned to Sunnyvale. After a brief stopover in systems test complex C-10, the vehicle was transferred to the anechoic chamber for elecromagnetic interference and radio-frequency-interference tests. Additional Details: here....
Gemini Agena target vehicle 5001 completed electromagnetic compatibility tests in the anechoic chamber at Sunnyvale. It remained in the chamber, however, until March 17 while Lockheed verified the corrective action that had been taken to eliminate programmer time-accumulator jumps and telemetry synchronization problems. The vehicle was then transferred to systems test complex C-10 for final Vehicle Systems Tests on March 18.
Manned Spacecraft Center delivered the 'Gemini Atlas Agena Target Vehicle Systems Management and Responsibilities Agreement' to Air Force Space Systems Division (SSD) with signatures of Director Robert R. Gilruth and Gemini Program Manager Charles W. Mathews (dated April 9). Major General Ben I. Funk, SSD Commander, and Colonel John B. Hudson, SSD Deputy for Launch Vehicles, had signed for SSD on March 31 and 29 respectively. The agreement, dated March 1965, followed months of negotiation and coordination on management relationships and fundamental responsibilities for the Gemini Agena target vehicle program. It clarified and supplemented the 'Operational and Management Plan for the Gemini Program' (December 29, 1961) with respect to the target vehicle program.
Gemini Agena target vehicle (GATV) 5001 completed vehicle systems testing with a final simulated flight. The vehicle was disconnected from the test complex on May 14, and data analysis was completed May 19. Meanwhile, the First Article Configuration Inspection on GATV 5001 began on May 10.
First Article Configuration Inspection (FACI) of Gemini Agena target vehicle (GATV) 5001 at Sunnyvale. A team of representatives from NASA, Air Force Space Systems Division, Aerospace, and Lockheed began the First Article Configuration Inspection (FACI) of Gemini Agena target vehicle (GATV) 5001 at Sunnyvale. Additional Details: here....
Gemini Agena target vehicle (GATV) 5002 completed final assembly and was transferred to systems test complex C-10 at Sunnyvale to begin Vehicle Systems Tests. The transfer had been scheduled for May 5 but was delayed by parts shortages, engineering problems, and considerable work backlog. The major source of delay was correcting a gap between the forward auxiliary rack and the vehicle; machining and aligning the rack and refinishing the scraped surfaces proved time-consuming. GATV 5002 was still short several items of command equipment. Systems testing began May 21.
Air Force Space Systems Division (SSD), following standard Air Force acceptance procedure using DD Form 250, found Gemini Agena target vehicle (GATV) 5001 not acceptable. This was because First Article Configuration Inspection (completed May 26) showed the vehicle not to be flightworthy as required by the contract. Additional Details: here....
Gemini Agena target vehicle 5001 arrived at Cape Kennedy following its conditional acceptance by the Air Force on May 27. It was moved to the Missile Assembly Building (Hanger E) for testing. The target vehicle was mated with target docking adapter No. 1 on June 18, and Combined Interface Tests began June 19. Testing was completed July 8 with secondary propulsion system (SPS) functional and static leak checks, SPS installation and postinstallation checks, and thermal control surface preparation. Target vehicle 5001 was then transferred to complex 14 to be mated to target launch vehicle 5301.
Gemini Agena target vehicle 5002 completed Vehicle Systems Tests at Sunnyvale, and the final acceptance test was conducted. The vehicle was disconnected from the test complex on July 13, after NASA, Air Force Space Systems Division, Aerospace, and Lockheed representatives agreed that all data discrepancies from the final systems tests had been resolved.
Air Force Space Systems Division formally accepted delivery of Gemini Agena target vehicle (GATV) 5002 after the vehicle acceptance team inspection had been completed. The vehicle was then shipped by air to Eastern Test Range on July 24, arriving July 25. Although GATV 5002 was accepted, several items of equipment remained in 'not qualified' status, including the shroud, secondary and primary propulsion systems, and components of both the electrical power and command systems.
Standard Agena D (AD-108), which had been completed in June and held in storage, was transferred to Building 104 at Sunnyvale for modifications and final assembly as Gemini Agena target vehicle 5003. While in storage, several pieces of AD-108 equipment had been removed for modification to the Gemini configuration. Final assembly began August 8.
Atlas standard launch vehicle 5301 and Gemini Agena target vehicle (GATV) 5001 were demated at complex 14, following the Simultaneous Launch Demonstration of July 22. GATV 5001 was returned to Hanger E, where it was stored as the backup vehicle for GATV 5002. On August 18, GATV 5002 was officially designated as the target vehicle for Gemini VI, the first rendezvous mission, while GATV 5001 was to be maintained in flight-ready condition as backup. Atlas 5301, which had been returned to Hanger J after demating, was moved back to complex 14 on August 16 to serve as the target launch vehicle for GATV 5002.
Gemini Agena target vehicle 5002 completed preliminary systems testing at Hanger E and was transferred to Merritt Island Launch Area, where it was joined by spacecraft No. 6 for Plan X testing. After ground equipment checks, Plan X tests proceeded on August 25. No significant interference problems were found, and testing ended on August 31.
Final troubleshooting on Gemini Agena target vehicle (GATV) 5002 after Plan X testing at Merritt Island Launch Area (MILA) was completed. The next day GATV 5002 was returned to Hanger E from MILA, where it began a series of tests to verify the operational readiness of all vehicle systems prior to erection and mating with the launch vehicle.
Gemini Agena target vehicle 5002 was transported to complex 14 and mated to target launch vehicle 5301. Preliminary checks were followed, on October 4, by the Joint Flight Acceptance Composite Test (J-FACT). J-FACT was a combined check of all contractors, the range, the vehicles, and aerospace ground equipment in a simulated countdown and flight; propellants and high pressure gases were not loaded, nor was the gantry removed. Simultaneous Launch Demonstration was successfully completed October 7.
The Wet Mock Simulated Launch (WMSL) of Gemini-Titan (GT) 6 and the Simultaneous Launch Demonstration with GT-6 and the Gemini Atlas-Agena target vehicle were conducted. Following WMSL, the spacecraft and launch vehicle were demated to allow the spacecraft battery to be replaced. They were remated October 8-13. Spacecraft Systems Test was completed October 15. Prelaunch testing concluded October 20 with the Simulated Flight Test.
The Gemini VI mission was canceled when Gemini Agena target vehicle (GATV) 5002 suffered what appeared to be a catastrophic failure shortly after separating from the Atlas launch vehicle. The Gemini Atlas-Agena target vehicle was launched from complex 14 at 10:00 a.m., e.s.t. When the two vehicles separated at 10:05, all signals were normal. But approximately 375 seconds after liftoff, vehicle telemetry was lost and attempts to reestablish contact failed. The Gemini VI countdown was held and then canceled at 10:54 a.m., because the target vehicle had failed to achieve orbit. In accordance with Air Force Space Systems Division (SSD) procedures and NASA management instructions - both of which specified investigation in the event of such a failure - Major General Ben I. Funk, SSD Commander, reconvened the Agena Flight Safety Review Board, and NASA established a GATV Review Board.
Catastrophic anomaly of Gemini Agena target vehicle (GATV) 5002 on October 25 defined as a mission failure. NASA Associate Administrator Robert C. Seamans, Jr., informed George E. Mueller, Associate Administrator for Manned Space Flight, that the catastrophic anomaly of Gemini Agena target vehicle (GATV) 5002 on October 25 had been defined as a mission failure. Additional Details: here....
The major portion of 819 discrepancies remaining from the First Article Configuration Inspection (FACI) of Gemini Agena target vehicle 5001 in June were cleared; 128 that had not been applied against the acceptance document (DD-250) remained. All subsystem FACI discrepancies were also closed out during October.
The Agena Flight Safety Review Board met at Lockheed to continue its investigation of the failure of Gemini Agena target vehicle 5002 on October 25. The board, chaired by George E. Mueller, NASA Associate Administrator of Manned Space Flight, reviewed the findings of the subpanel for Gemini VI and reached the same conclusion: the failure resulted from a hard start probably caused by the fuel lead. Additional Details: here....
Because too little diagnostic information had been obtained from the flight of Gemini Agena target vehicle (GATV) 5002 to determine the exact nature of the probable hard start, it was not certain that the proposed modification - a return to oxidizer lead - would definitely prevent a recurrence of the malfunctions. Additional Details: here....
Lockheed presented its proposed Gemini Agena target vehicle (GATV) engine modification and test program to Colonel A. J. Gardner, Gemini Target Vehicle Program Director, Air Force Space Systems Division (SSD). The proposal was immediately turned over to a three-man team comprising B. A. Hohmann (Aerospace), Colonel J. B. Hudson (Deputy Commander for Launch Vehicles, SSD), and L. E. Root (Lockheed) for consideration. On November 18, the group decided on a final version of the proposal that called for: (1) modifying the Agena engine to provide oxidizer lead during the start sequence, (2) demonstrating sea-level engine flightworthiness in tests at Bell Aerosystems, and (3) conducting an altitude test program at Arnold Engineering Development Center. The final proposal was presented to the GATV Review Board at Manned Spacecraft Center on November 20.
Air Force Space Systems Division (SSD) directed Lockheed to return Gemini Agena target vehicle (GATV) 5001 to Sunnyvale. The GATV was still being stored in Hanger E, Eastern Test Range, minus its main engine which SSD had directed Lockheed to ship to Bell Aerosystems on November 9 for modification. Additional Details: here....
Lockheed submitted an engineering change proposal to Air Force Space Systems Division (SSD) for Project Surefire. Surefire was the code name for the Gemini Agena Target Vehicle (GATV) Modification and Test Program designed to correct the malfunction which had caused the failure of GATV 5002 on October 25. Additional Details: here....
Air Force Space Systems Division authorized Lockheed to begin the disassembly and inspection of Gemini Agena target vehicle 5001 to determine the extent of refurbishment needed. The vehicle was stripped down to its major structural components to expose all areas of possible contamination.
The Air Force accepted the main rocket engine for Gemini Agena target vehicle (GATV) 5003 after Bell Aerosystems had completed Project Surefire modifications. The engine was shipped immediately and arrived at Lockheed December 18. Lockheed completed reinstalling the engine on December 20. GATV 5003 systems retesting began December 27 after other equipment modifications had been installed.
Gemini Agena target vehicle (GATV) 5003 completed its final acceptance tests at Sunnyvale, after an elusive command system problem had made it necessary to rerun the final systems test (January 4). No vehicle discrepancy marred the rerun. Air Force Space Systems Division formally accepted GATV 5003 on January 18, after the vehicle acceptance team inspection. It was shipped to Eastern Test Range the same day, but bad weather delayed delivery until January 21. GATV 5003 was to be the target vehicle for Gemini VIII.
Bell's part in the test program was to demonstrate the sea-level flightworthiness of the modified Agena main engine. Bell completed testing on March 4 with a full 180-second mission simulation firing. The successful completion of this phase of the test program gave the green light for the launch of Gemini Agena target vehicle 5003, scheduled for March 15.
McDonnell had delivered TDA-3 to Cape Kennedy on January 8. The GATV/TDA interface functional test was completed January 24, and the vehicle was transferred to Merritt Island Launch Area for integrated tests with spacecraft No. 8 and extravehicular equipment, which were completed January 28.
Gemini Agena target vehicle (GATV) 5004 was transferred to the vehicle systems test area at Sunnyvale. Its modified main engine had been received on schedule from Bell Aerosystems January 12 and installed by January 20. Because of GATV 5003 priority, however, several main electronic assemblies, including the command system, had been removed from GATV 5004 and used in GATV 5003 final acceptance tests. As a result, GATV 5004 had fallen eight days behind its scheduled transfer date, January 18.
Gemini Agena target vehicle (GATV) 5003 was returned to Hanger E after completing Plan X tests at Merritt Island Launch Area. Systems Verification and Combined Interface Tests were conducted through February 18, followed by functional checks of the primary and secondary propulsion systems. Hanger E testing ended February 28, and the GATV was transferred to complex 14.
After ground equipment compatibility tests, the Joint Flight Acceptance Composite Test was successfully performed on March 7. Simultaneous Launch Demonstration March 8-9 completed Gemini Atlas-Agena target vehicle systems testing in preparation for launch on March 15 as part of the Gemini VIII mission.
Following the early termination of Gemini VIII, Gemini Agena target vehicle (GATV) 5003 remained in orbit, where its various systems were extensively exercised. The main engine was fired nine times, four more than required by contract, and 5000 commands were received and executed by the command and communications system, as against a contractural requirement of 1000. Additional Details: here....
Gemini Agena target vehicle 5005 completed modification and final assembly with the installation of a number of electrical and electronic components for which it had been waiting. These included the guidance module, flight control junction box, and flight electronics package. The vehicle was transferred to test complex C-10 at Sunnyvale to begin Vehicle Systems Tests. Preliminary test tasks were completed by April 23, with preliminary inspection on April 26-27.
Gemini Agena target vehicle 5004 began the Combined Interface Test (CIT) at Hanger E, Eastern Test Range, after completing Plan X tests March 24. CIT ended April 22 and engine functional tests of both the primary and secondary propulsion systems followed. Hanger E testing was completed May 1.
Lockheed established a task force to handle the refurbishing of Gemini Agena target vehicle (GATV) 5001 and announced a GATV 5001 Reassembly Plan. The task force's function was to see that GATV 5001 reached a flightworthy condition on time and as economically as possible. The reassembly plan provided an operational base line as well as guidelines for reassembling the vehicle, which was completely disassembled down to the level of riveted or welded parts. GATV 5001 was scheduled for acceptance on September 20 and would be the target vehicle for Gemini XII.
The scheduled launch of Gemini IX was postponed when target launch vehicle 5303 malfunctioned and, as a result, Gemini Agena target vehicle 5004 failed to achieve orbit. Launch and flight were normal until about 120 seconds after liftoff, 10 seconds before booster engine cutoff. Additional Details: here....
The Gemini 9 mission was scrubbed when the Atlas booster launched from Cape Canaveral failed to place the Gemini Agena Target Vehicle (GATV) in its planned circular orbit. A malfunction of the number 2 booster engine of the Atlas caused both the Atlas and Agena to fall into the ocean. The Gemini 9-Atlas/Agena mission was later rescheduled to 1 June using the Augmented Target Docking Adapter (ATDA).
Gemini Agena target vehicle 5005 was mated to the target docking adapter (TDA) in Hanger E at Cape Kennedy. McDonnell had delivered the TDA on May 4. After mating, interface functional tests were performed, May 25-27. Preparations then began for Plan X testing with spacecraft No. 10 at Merritt Island Launch Area.
Gemini Agena target vehicle 5005 completed preliminary testing at Hanger E, Eastern Test Range, and was moved to Merritt Island Launch Area for Plan X tests with spacecraft No. 10. Plan X tests had first been scheduled for May 23 but were rescheduled for June 2-3. Additional Details: here....
Gemini Agena target vehicle 5006 completed modification and final assembly and was transferred to Vehicle Systems Test (VST) at Sunnyvale. Although the vehicle lacked the flight control electronics package and guidance module, testing began immediately. The guidance module was received June 7 and the flight control electronics package June 9. Preliminary VST was completed June 17. The Air Force Plant Representative Office at Sunnyvale authorized final acceptance test to begin on June 20.
NASA announced that the Gemini X mission had been scheduled for no earlier than July 18, with John W. Young, command pilot, and Michael Collins, pilot, as the prime crew. Alan L. Bean, command pilot, and Clifton C. Williams, pilot, would be the backup crew. Mission plans would include rendezvous, docking, and extravehicular activity. The spacecraft was scheduled to rendezvous and dock with an Agena target vehicle which was to be launched the same day. If possible, Gemini X would also rendezvous with the Agena launched in the March 16 Gemini VIII mission.
Gemini Agena target vehicle 5005 was transferred to complex 14 and mated to target launch vehicle 5305. Joint Flight Acceptance Composite Test was completed July 8. Complex 14 systems tests were completed July 12 with the Simultaneous Launch Demonstration.
An Air Force Titan Gemini Launch Vehicle placed the Gemini 10 (GT-10) spacecraft into orbit for the three-day mission of Astronauts John Young and Michael Collins. Rendezvous and docking were accomplished with the Gemini Agena Target Vehicle (GATV) that had been launched from Cape Kennedy aboard an Atlas Booster just ahead of GT-10. Using the GATV-10 Primary Propulsion System (PPS), the docked vehicles achieved a manned-flight altitude record of 476 miles. Reentry was accomplished on 21 July and recovery was made 544 miles east of Cape Canaveral. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).
Following the reentry of spacecraft No. 10, Gemini Agena target vehicle (GATV) 5005 made three orbital maneuvers under ground control. Its primary propulsion system (PPS) fired to put the vehicle in a 750.5 by 208.6 nautical mile orbit in order to determine the temperature effects of such an orbit on the vehicle. Additional Details: here....
After completing Plan X tests at Merritt Island Launch Area, Gemini target vehicle (GATV) 5006 returned to Hanger E to begin systems verification tests. Combined Interface Tests began August 4 and ended August 12. Primary and secondary propulsion system (PPS and SPS) functional tests began August 13. SPS functionals were completed August 18, and the SPS modules were installed August 19. PPS functionals were completed August 21. GATV 5006 was then transferred to complex 14 for mating with the Atlas.
Electrical power was applied the following day. The dual propellant loading (DPL) was run August 18, after a number of liquid oxygen leaks had been eliminated. A discrepancy noted in the vernier engine liquid oxygen bleed system during the first loading required a second DPL, successfully completed on August 22. The Booster Flight Acceptance Composite Test was successfully completed on August 19, and the TLV and Gemini Agena target vehicle were mated on August 22.
Gemini Agena target vehicle (GATV) 5001 was returned to Hanger E and began systems test after completing Plan X tests at the Merritt Island Launch Area. Systems testing was completed September 29. The Combined Interface Test (September 29-October 13) was followed by functional tests of the primary and secondary propulsion systems, completed October 22. GATV 5001 was then moved to complex 14.