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Gemini REP


Gemini REP Development Diary

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Gemini REP Chronology


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 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..

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 July 10 - . LV Family: Titan. Launch Vehicle: Titan 2.
  • Manager Charles W. Mathews reported that the Gemini Program Office had been reviewing and evaluating plans for Gemini-Titan (GT) missions 4 through 7. - . Nation: USA. Flight: Gemini 4; Gemini 5; Gemini 6. Spacecraft: Gemini; Gemini Fuel Cell; Gemini REP. Summary: GT-4 would be a four-day mission using battery power. . Additional Details: here....

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.


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