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Gemini Radar


Gemini Radar Development Diary

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Gemini Radar Chronology


1962 January 31 - .
  • 11 Atlas-Agenas rendezvous targets requested for Project Gemini. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Manned Spacecraft Center notified Marshall Space Flight Center, Huntsville, Alabama (which was responsible for managing NASA's Agena Programs) that Project Gemini required 11 Atlas-Agenas as rendezvous targets and requested Marshall to procure them. The procurement request was accompanied by an Exhibit 'A' describing proposed Gemini rendezvous techniques and defining the purpose of Project Gemini as development and demonstrating Earth-orbit rendezvous techniques as early as possible. If feasible, these techniques could provide a practical base for lunar and other deep space missions. Exhibit B to the purchase request was a Statement of Work for Atlas-Agena vehicles to be used in Project Gemini. Air Force Space Systems Division, acting as a NASA contractor, would procure the 11 vehicles required. Among the modifications needed to change the Atlas-Agena into the Agena rendezvous vehicle were: incorporation of radar and visual navigation and tracking aids; main engines capable of multiple restarts; addition of a secondary propulsion system, stabilization system, and command system; incorporation of an external rendezvous docking unit; and provision of a jettisonable aerodynamic fairing to enclose the docking unit during launch. The first rendezvous vehicle was to be delivered to the launch site in 20 months, with the remaining 10 to follow at 60-day intervals.

1962 March 5 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • 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. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. 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.

1962 April 7 - .
  • ACF Electronics Division, Riverdale, California, of ACF Industries, Inc., received a $1 million subcontract from McDonnell to provide C- and S-band radar beacons for the Gemini spacecraft. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. These beacons formed part of the spacecraft's tracking system. With the exception of frequency-dependent differences, the C-band beacon was nearly identical to the S-band beacon. Their function was to provide tracking responses to interrogation signals from ground stations.

1962 April 19 - .
  • McDonnell awarded a $26.6 million subcontract to International Business Machines (IBM) Corporation's Space Guidance Center, Owego, New York, to provide the computer system for the Gemini spacecraft. - . Nation: USA. Spacecraft: Gemini; Gemini Inertial Guidance System; Gemini Radar. The digital computer was the heart of the spacecraft's guidance and control system; supplementary equipment consisted of the incremental velocity indicator (which visually displayed changes in spacecraft velocity), the manual data insertion unit (for inserting data into, and displaying readouts from, the computer), and the auxiliary computer power unit (to maintain stable computer input voltages). In addition to providing the computer and its associated equipment, IBM was also responsible for integrating the computer with the systems and components it connected with electrically, including the inertial platform, rendezvous radar, time reference system, digital command system, data acquisition system, attitude control and maneuver electronics, the launch vehicle autopilot, console controls and displays, and aerospace ground equipment.

1962 May 1 - .
  • McDonnell proposed to evaluate the Gemini redezvous radar and spacecraft maneuvering system on early flights by using a rendezvous evaluation pod to be ejected from the spacecraft in orbit. - . Nation: USA. Spacecraft: Gemini; Gemini Radar; Gemini REP. Manned Spacecraft Center (MSC) liked the idea and asked McDonnell to pursue the study. During the last week in June, McDonnell received approval from MSC to go ahead with the design and development of the rendezvous pod. It would contain a radar transponder, C-band beacon, flashing light, and batteries.

1962 June 25 - .
  • Gemini Project Office reported that a thorough study of the reentry tracking histories of the Mercury-Atlas 4, 5, 6 and 7 missions had been completed. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Summary: The study indicated that a C-band radar tracking beacon should be integrated into the spacecraft reentry section in place of the planned S-band beacon. The change would improve the probability of tracking spacecraft reentry through the ionization zone..

1962 September 4 - .
  • Gemini Project Office directed McDonnell to provide spacecraft No. 3 with rendezvous radar capability and to provide a rendezvous evaluation pod as a requirement for missions 2 and 3. - . Nation: USA. Flight: Gemini 3. Spacecraft: Gemini; Gemini Radar; Gemini REP. Summary: Four pods were required: one prototype, two flight articles, and one flight spare..

1962 September 19 - .
  • ACF Electronics delivered an engineering prototype radar beacon to McDonnell. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Summary: An engineering prototype C-band beacon had operated at ACF Electronics under simulated reentry conditions with no degredation in performance..

1963 January 4 - .
  • Manned Spacecraft Center directed McDonnell to study requirements for a spacecraft capable of performing rendezvous experiments on the second and third Gemini flights. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. The experimental package would weigh 70 pounds and would include an L-band radar target, flashing light, battery power supply, and antenna systems. On the second flight, a one-day mission, the experiment was to be performed open-loop, probably optically - the astronaut would observe the target and maneuver the spacecraft to rendezvous with it. On the third flight, a seven-day mission, the experiment was to be performed closed-loop, with spacecraft maneuvers controlled automatically by the data it received from its instruments.

1963 February 15 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • Agena target vehicle checkout plans were presented at a meeting of the Gemini Management Panel. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Upon receipt at Cape Canaveral, the target vehicle would be inspected and certified. After this action, mechanical mate and interface checks with the target docking adapter would be accomplished. Agena-Gemini spacecraft compatibilty tests would then be conducted, and the Agena would undergo validation and weight checks. Subsequently, a joint checkout of the spacecraft and Agena would be conducted with tests on the Merritt Island radar tower.

1963 March 5 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • Gemini Project Office discussed with contractors the establishment of a philosophy for the final phase of the rendezvous mission. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. They agreed on the following general rules: (1) when the launch was on time, the terminal maneuver would be initiated when the Agena came within range of the spacecraft's sensors, which would occur between spacecraft insertion and first apogee; (2) automatic and optical terminal guidance techniques would always back each other up, one method being selected as an objective for each mission and the other serving as a standby; (3) during early rendezvous missions, the terminal phase would be initiated by the third spacecraft apogee or delayed until the twelfth because of range radar tracking limitations; (4) for the same reason, no midcourse corrections should be made during orbits 4 through 11; (5) in case of extreme plane or phase errors, the Agena would be maneuvered to bring it within the spacecraft's maneuver capability; and (6) after such gross Agena maneuvers, the Agena orbit would be recircularized and two orbits of spacecraft catchup would precede the initiation of terminal rendezvous plan.

1963 April 2 - .
  • $42.638 million increase in Gemini's actual 1963 budget. - . Nation: USA. Related Persons: Holmes, Brainard. Spacecraft: Gemini; Gemini Radar. Testifying before the Subcommittee on Manned Space Flight of the House Committee on Science and Astronautics, D Brainerd Holmes, Director of Manned Space Flight, sought to justify a $42.638 million increase in Gemini's actual 1963 budget over that previously estimated. Holmes explained: 'This increase is identified primarily with an increase of $49.9 million in spacecraft. The fiscal 1963 congressional budget request was made at the suggestion of the contractor. The increase reflects McDonnell's six months of actual experience in 1963.' The subcommittee was perturbed that the contractor could so drastically underestimate Gemini costs, especially since it was chosen without competition because of supposed competence derived from Mercury experience. Holmes attributed McDonnell's underestimate to unexpectedly high bids from subcontractors and provided for the record a statement of some of the reasons for the change: 'These original estimates made in December 1961 by NASA and McDonnell were based on minimum changes from Mercury technology ..... As detailed specifications for subsystems performance were developed ....... realistic cost estimates, not previously available, were obtained from subcontractors. The first of these ....... were obtained by McDonnell in April 1962 and revealed significantly higher estimates than were originally used. For example: (a) In data transmission, it became necessary to change from a Mercury-type system to a pulse code modulation (PCM) system because of increased data transmission requirements, and the need to reduce weight and electrical power. The Gemini data transmission system will be directly applicable to Apollo. (b) Other subsystems have a similar history. The rendezvous radar was originally planned to be similar to ones used by the Bomarc Missile, but it was found necessary to design an interferometer type radar for low weight, small volume, and to provide the highest reliability possible. (c) The environmental control system was originally planned as two Mercury-type systems, but as the detail specifications became definitive it was apparent that the Mercury ECS was inadequate and, although extensive use of Mercury design techniques were utilized, major modifications were required.'

1963 April 9 - .
  • George M Low, Director of Spacecraft and Flight Missions, Office of Manned Space Flight, explained to the House Subcommittee on Manned Space Flight why eight rendezvous missions were planned. - . Nation: USA. Spacecraft: Gemini; Gemini Inertial Guidance System; Gemini Radar. 'In developing the rendezvous capability, we must study a number of different possible ways of conducting the rendezvous ..... For example, we can conduct a rendezvous maneuver in Gemini by purely visual or optical means. In this case there will be a flashing light on the target vehicle. The pilot in the spacecraft will look out of his window and he will rendezvous and fly the spacecraft toward the flashing light and perform the docking. This is one extreme of a purely manual system. On the opposite end of the spectrum we have a purely automatic system in which we have a radar, computer, and stabilized platform and, from about 200 or 500 miles out, the spacecraft and the target vehicle can lock on to each other by radar and all maneuvers take place automatically from that point on. We know from our studies on the ground and our simulations that the automatic way is probably the most efficient way of doing it. We would need the least amount of fuel to do it automatically. On the other hand it is also the most complex way. We need more equipment, and more equipment can fail this maneuver so it might not be the most reliable way. The completely visual method is least efficient as far as propellants are concerned, but perhaps the simplest. In between there are many possible combinations of these things. For example, we could use a radar for determining the distance and the relative velocity between the two without determining the relative angle between the two spacecraft and let the man himself determine the relative angle. We feel we must get actual experience in space flight of a number of these possibilities before we can perform the lunar orbit rendezvous for Apollo.'

1963 June 19 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • The Cape Gemini/Agena Test Integration Working Group met to define "Plan X" test procedures and responsibilities. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. 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.

1963 September 4 - .
  • Representatives of Manned Spacecraft Center's Instrumentation and Electronics Systems Division and McDonnell met to coordinate the Gemini radar program. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Summary: Gemini Project Office had requested an increased effort to put the rendezvous radar system in operational status..

1963 September 11-12 - .
  • Gemini rendezvous radar system be brought to operational status. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Following up Gemini Project Office's request to bring the Gemini rendezvous radar system to operational status, Manned Spacecraft Center Instrumentation and Electronics System Division personnel met with Westinghouse at Baltimore to review the test program. Westinghouse had completed its radio frequency anechoic chamber test, but test anomalies could not be pinpointed to the radar system, since chamber reflections might have been responsible. An outdoor range test was planned to determine whether the chamber was suitable for testing the radar.

1964 January 1 - . LV Family: Atlas; Titan.
  • NASA Headquarters directed Gemini Project Office to take the radar and rendezvous evaluation pod out of Gemini-Titan (GT) missions 3 and 4. - . Nation: USA. Flight: Gemini 4; Gemini 5. Spacecraft: Gemini; Gemini Radar; Gemini REP. Summary: GT-4 would be a battery-powered long-duration flight. The pod would go on GT-5, and thus the first planned Agena flight would probably slip in the schedule..

1964 March 25 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • Gemini mission plans for the first Agena rendezvous flight. - . Nation: USA. Related Persons: Aldrin. Spacecraft: Gemini; Gemini Radar. At a meeting of the Gemini Project Office's Trajectories and Orbits Panel, members of Flight Operations Division described two mission plans currently under consideration for the first Agena rendezvous flight. One was based on the concept of tangential Agena and spacecraft orbits, as proposed by Howard W. Tindall, Jr., and James T. Rose when they were members of Space Task Group. The second plan, based on a proposal by Edwin E. Aldrin, Jr., then of Air Force Space Systems Division, involved orbits which were concentric rather than tangential. The most significant advantage of the second plan was that it provided the greatest utilization of onboard backup techniques; that is, it was specifically designed to make optimum use of remaining onboard systems in the event of failure in the inertial guidance system platform, computer, or radar.

1964 April 30 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • First Agena D for the Gemini program. - . Nation: USA. Program: Gemini. Flight: Gemini 12. Spacecraft: Gemini; Gemini Radar. 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.

1964 September 25-26 - .
  • Representatives from Instrumentation and Electronics Division conducted preliminary rendezvous radar flight tests at White Sands Missile Range. - . Nation: USA. Spacecraft: Gemini; Gemini Radar. Summary: Testing was interrupted while the T-33 aircraft being used was down for major maintenance and was then resumed on October 19. Flight testing of the rendezvous radar concluded December 8..

1964 October 10 - .
  • First production rendezvous radar accepted. - . Nation: USA. Flight: Gemini 5. Spacecraft: Gemini; Gemini Radar. Summary: Gemini Program Office reported that the first production rendezvous radar, intended for spacecraft No. 5, had completed its predelivery acceptance test. .

1965 January 4 - .
  • McDonnell delivered Gemini spacecraft No. 3 to Cape Kennedy. - . Nation: USA. Flight: Gemini 3. Spacecraft: Gemini; Gemini Radar. After its receiving inspection had been completed (January 6), the spacecraft was moved to the Merritt Island Launch Area Radar Range for a communications radiation test. This test, performed only on spacecraft No. 3 because it was scheduled for the first manned mission, exercised spacecraft communications in a radio-frequency environment closely simulating the actual flight environment. The test was run January 7, and the spacecraft then began preparations for static firing.

1965 August 21 - . 14:00 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC19. LV Family: Titan. Launch Vehicle: Titan II GLV. LV Configuration: Titan II GLV GT-5 / 62-12560.
  • Gemini 5 - . Call Sign: Gemini 5. Crew: Conrad; Cooper. Backup Crew: Armstrong; See. Payload: Gemini SC5/Rendezvous Evaluation Pod. Mass: 3,605 kg (7,947 lb). Nation: USA. Related Persons: Conrad; Cooper; Armstrong; See. Agency: NASA Houston. Program: Gemini. Class: Manned. Type: Manned spacecraft. Flight: Gemini 5. Spacecraft: Gemini; Gemini Radar; Gemini REP. Duration: 7.96 days. Decay Date: 1965-08-29 . USAF Sat Cat: 1516 . COSPAR: 1965-068A. Apogee: 395 km (245 mi). Perigee: 304 km (188 mi). Inclination: 32.6000 deg. Period: 91.50 min. Major objectives of the eight-day mission were evaluating the performance of the rendezvous guidance and navigation system, using a rendezvous evaluation pod (REP), and evaluating the effects of prolonged exposure to the space environment on the flight crew. Secondary objectives included demonstrating controlled reentry guidance, evaluating fuel cell performance, demonstrating all phases of guidance and control system operation needed for a rendezvous mission, evaluating the capability of either pilot to maneuver the spacecraft in orbit to rendezvous, evaluating the performance of rendezvous radar, and executing 17 experiments. The mission proceeded without incident through the first two orbits and the ejection of the REP. About 36 minutes after beginning evaluation of the rendezvous guidance and navigation system, the crew noted that the pressure in the oxygen supply tank of the fuel cell system was falling. Pressure dropped from 850 pounds per square inch absolute (psia) at 26 minutes into the flight until it stabilized at 70 psia at 4 hours 22 minutes, and gradually increased through the remainder of the mission. The spacecraft was powered down and the REP exercise was abandoned. By the seventh revolution, experts on the ground had analyzed the problem and a powering-up procedure was started. During the remainder of the mission the flight plan was continuously scheduled in real time. Four rendezvous radar tests were conducted during the mission, the first in revolution 14 on the second day; the spacecraft rendezvous radar successfully tracked a transponder on the ground at Cape Kennedy. During the third day, a simulated Agena rendezvous was conducted at full electrical load. The simulation comprised four maneuvers - apogee adjust, phase adjust, plane change, and coelliptical maneuver - using the orbit attitude and maneuver system (OAMS). Main activities through the fourth day of the mission concerned operations and experiments. During the fifth day, OAMS operation became sluggish and thruster No. 7 inoperative. Thruster No. 8 went out the next day, and the rest of the system was gradually becoming more erratic. Limited experimental and operational activities continued through the remainder of the mission. Retrofire was initiated in the 121st revolution during the eighth day of the mission, one revolution early because of threatening weather in the planned recovery area. Reentry and landing were satisfactory, but the landing point was 145 km short, the result of incorrect navigation coordinates transmitted to the spacecraft computer from the ground network. Landing occurred August 29, 190 hours 55 minutes after the mission had begun. The astronauts arrived on board the prime recovery ship, the aircraft carrier Lake Champlain, at 9:25. The spacecraft was recovered at 11:51 a.m.

    With this flight, the US finally took the manned spaceflight endurance record from Russia, while demonstrating that the crew could survive in zero gravity for the length of time required for a lunar mission. However the mission was incredibly boring, the spacecraft just drifting to conserve fuel most of the time, and was 'just about the hardest thing I've ever done' according to a hyperactive Pete Conrad. An accident with freeze dried shrimp resulted in the cabin being filled with little pink subsatellites.


1965 August 31 - .
  • Gemini Program Office reported that during the missions of Gemini 4 and 5, skin-tracking procedures had been successfully developed. - . Nation: USA. Flight: Gemini 4. Spacecraft: Gemini; Gemini Radar. On these missions, the C-band radars were able to track the spacecraft in both the beacon and skin-track mode. It was, therfore, possible to obtain tracking data when the spacecraft was powered down and had no tracking beacons operating. As a result, the skin-tracking procedures were integrated into the network support for all remaining Gemini missions.

1965 November 26 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • McDonnell proposed building a backup target vehicle for Gemini rendezvous missions. - . Nation: USA. Flight: Gemini 8. Spacecraft: Gemini; Gemini Radar. The augmented target docking adapter (ATDA) would serve as an alternative to the Gemini Agena target vehicle (GATV) if efforts to remedy the GATV problem responsible for the October 25 mission abort did not meet the date scheduled for launching Gemini VIII. Additional Details: here....

1965 December 15 - . 13:37 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC19. LV Family: Titan. Launch Vehicle: Titan II GLV. LV Configuration: Titan II GLV GT-6 / 62-12561.
  • Gemini 6 - . Call Sign: Gemini 6. Crew: Schirra; Stafford. Backup Crew: Grissom; Young. Payload: Gemini SC6. Mass: 3,546 kg (7,817 lb). Nation: USA. Related Persons: Schirra; Stafford; Grissom; Young. Agency: NASA Houston. Program: Gemini. Class: Manned. Type: Manned spacecraft. Flight: Gemini 6; Gemini 7. Spacecraft: Gemini; Gemini Radar. Duration: 1.08 days. Decay Date: 1965-12-16 . USAF Sat Cat: 1839 . COSPAR: 1965-104A. Apogee: 271 km (168 mi). Perigee: 258 km (160 mi). Inclination: 28.9000 deg. Period: 89.60 min. The primary objective of the mission, crewed by command pilot Astronaut Walter M. Schirra, Jr., and pilot Astronaut Thomas P. Stafford, was to rendezvous with spacecraft No. 7. Among the secondary objectives were stationkeeping with spacecraft No. 7, evaluating spacecraft reentry guidance capability, testing the visibility of spacecraft No. 7 as a rendezvous target, and conducting three experiments. After the launch vehicle inserted the spacecraft into an 87 by 140 nautical mile orbit, the crew prepared for the maneuvers necessary to achieve rendezvous. Four maneuvers preceded the first radar contact between the two spacecraft. The first maneuver, a height adjustment, came an hour and a half after insertion, at first perigee; a phase adjustment at second apogee, a plane change, and another height adjustment at second perigee followed. The onboard radar was turned on 3 hours into the mission. The first radar lock-on indicated 246 miles between the two spacecraft. The coelliptic maneuver was performed at third apogee, 3 hours 47 minutes after launch. The terminal phase initiation maneuver was performed an hour and a half later. Two midcourse corrections preceded final braking maneuvers at 5 hours 50 minutes into the flight. Rendezvous was technically accomplished and stationkeeping began some 6 minutes later when the two spacecraft were about 120 feet apart and their relative motion had stopped. Stationkeeping maneuvers continued for three and a half orbits at distances from 1 to 300 feet. Spacecraft No. 6 then initiated a separation maneuver and withdrew to a range of about 30 miles. The only major malfunction in spacecraft No. 6 during the mission was the failure of the delayed-time telemetry tape recorder at 20 hours 55 minutes ground elapsed time, which resulted in the loss of all delayed-time telemetry data for the remainder of the mission, some 4 hours and 20 minutes. The flight ended with a nominal reentry and landing in the West Atlantic, just 10 km from the planned landing point, on December 16. The crew remained in the spacecraft, which was recovered an hour later by the prime recovery ship, the aircraft carrier Wasp.

    Gemini 6 was to have been the first flight involving docking with an Agena target/propulsion stage. However the Agena blew up on the way to orbit, and the spacecraft was replaced by Gemini 7 in the launch order.

    For lack of a target, NASA decided to have Gemini 6 rendezvous with Gemini 7. This would require a quick one week turnaround of the pad after launch, no problem with Russian equipment but a big accomplishment for the Americans. The first launch attempt was aborted; the Titan II ignited for a moment, then shut down and settled back down on its launch attachments. Schirra waited it out, did not pull the abort handles that would send the man catapulting out of the capsule on their notoriously unreliable ejection seats. The booster was safed; Schirra had saved the mission and the launch three days later went perfectly. The flight went on to achieve the first manned space rendezvous controlled entirely by the self-contained, on-board guidance, control, and navigation system. This system provided the crew of Gemini 6 with attitude, thrusting, and time information needed for them to control the spacecraft during the rendezvous. Under Schirra's typically precise command, the operation was so successful that the rendezvous was complete with fuel consumption only 5% above the planned value to reach 16 m separation from Gemini 7.


1966 March 21 - . LV Family: Atlas. Launch Vehicle: Atlas Agena D SLV-3.
  • Gemini Agena target vehicle 5004 and spacecraft No. 9 began Plan X compatibility tests at Merritt Island Launch Area Radar Range. - . Nation: USA. Flight: Gemini 9. Spacecraft: Gemini; Gemini Radar.

1966 November 11 - . 20:46 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC19. LV Family: Titan. Launch Vehicle: Titan II GLV. LV Configuration: Titan II GLV GT-12 / 62-12567.
  • Gemini 12 - . Call Sign: Gemini 12. Crew: Aldrin; Lovell. Backup Crew: Cernan; Cooper. Payload: Gemini SC12. Mass: 3,763 kg (8,295 lb). Nation: USA. Related Persons: Aldrin; Lovell; Cernan; Cooper. Agency: NASA Houston. Program: Gemini. Class: Manned. Type: Manned spacecraft. Flight: Gemini 12. Spacecraft: Gemini; Gemini Radar. Duration: 3.94 days. Decay Date: 1966-11-15 . USAF Sat Cat: 2566 . COSPAR: 1966-104A. Apogee: 289 km (179 mi). Perigee: 250 km (150 mi). Inclination: 28.8000 deg. Period: 89.90 min. Two very serious astronauts get it all right to end the program. Docked and redocked with Agena, demonstrating various Apollo scenarios including manual rendezvous and docking without assistance from ground control. Aldrin finally demonstrates ability to accomplish EVA without overloading suit by use of suitable restraints and careful movement.

    Major objectives of the mission were to rendezvous and dock and to evaluate extravehicular activities (EVA). Among the secondary objectives were tethered vehicle evaluation, experiments, third revolution rendezvous and docking, automatic reentry demonstration, docked maneuvering for a high-apogee excursion, docking practice, systems tests, and Gemini Agena target vehicle (GATV) parking. The high-apogee excursion was not attempted because an anomaly was noted in the GATV primary propulsion system during insertion, and parking was not attempted because the GATV's attitude control gas was depleted. All other objectives were achieved. Nine spacecraft maneuvers effected rendezvous with the GATV. The onboard radar malfunctioned before the terminal phase initiate maneuver, but the crew used onboard backup procedures to calculate the maneuvers. Rendezvous was achieved at 3 hours 46 minutes ground elapsed time, docking 28 minutes later. Two phasing maneuvers, using the GATV secondary propulsion system, were accomplished, but the primary propulsion system was not used. The first of two periods of standup EVA began at 19 hours 29 minutes into the flight and lasted for 2 hours 29 minutes. During a more than two-hour umbilical EVA which began at 42 hours 48 minutes, Aldrin attached a 100-foot tether from the GATV to the spacecraft docking bar. He spent part of the period at the spacecraft adapter, evaluating various restraint systems and performing various basic tasks. The second standup EVA lasted 55 minutes, ending at 67 hours 1 minute ground elapsed time. The tether evaluation began at 47 hours 23 minutes after liftoff, with the crew undocking from the GATV. The tether tended to remain slack, although the crew believed that the two vehicles did slowly attain gravity-gradient stabilization. The crew jettisoned the docking bar and released the tether at 51 hours 51 minutes. Several spacecraft systems suffered problems during the flight. Two fuel cell stacks failed and had to be shut down, while two others experienced significant loss of power. At 39 hours 30 minutes ground elapsed time, the crew reported that little or no thrust was available from two orbit attitude and maneuver thrusters.


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