|Gemini 6 2|
View of Gemini 6 during the Gemini 6 and 7 first space rendeavous.
Credit: NASA. 17,867 bytes. 451 x 297 pixels.
It was obvious to NASA that there was a big gap of three to four years between the last Mercury flight and the first scheduled Apollo flight. There would therefore be no experience in the US in understanding the problems of orbital manoeuvring, rendezvous, docking, lifting re-entry, and space walking before the Apollo flights, which required all of these to be successfully accomplished to complete the lunar landing mission.
Gemini began as Mercury Mark II to fill this gap. The concept was to enlarge the Mercury capsule's basic design to accommodate two crew, provide it with orbital manoeuvring capability, use existing boosters to launch it and an existing upper rocket stage as a docking target. The latest aircraft engineering was exploited , resulting in a modularised design that provided easy access to and changeout of equipment mounted external to the crew's pressure vessel. In many ways the Gemini design was ahead of that of the Apollo, since the project began two years later . The crew station layout was similar to that of the latest military fighters; the capsule was equipped with ejection seats, inertial navigation, the pilot's traditional 8-ball attitude display, and radar. The escape tower used for Mercury was deleted; the propellants used in the Titan II launch vehicle, while toxic, corrosive, poisonous, and self-igniting, did not explode in the manner of the Atlas or Saturn LOX/Kerosene combination. The ejection seats served as the crew escape method in the lower atmosphere, just as in a high-performance aircraft. The seats were also needed for the original landing mode, which involved deployment of a huge inflated Rogallo wing (ancestor of today's hang gliders) with a piloted landing on skids at Edwards Dry Lake. In the event, the wing could not be made to deploy reliably before flights began, so the capsule made a parachute-borne water landing, much to the astronauts' chagrin.
|Titan 2 Gemini - The Titan 2 ICBM was used for launch of the Gemini manned spacecraft.|
Credit: NASA. 24,744 bytes. 351 x 453 pixels.
Early on it was proposed that the Gemini could be used for manned circumlunar or lunar missions at a fraction of the cost and much earlier than Apollo. Truth be told, a Gemini launched atop a Titan 3E or Saturn IVB Centaur could have accomplished a circumlunar flight as early as 1966 and, using earth orbit rendezvous techniques, a landing at least a year before Apollo. But the capsule, while perhaps suited as a ferry vehicle to space stations, would have been quite marginal for the lunar mission due to the cramped accommodation. But mainly NASA was fully committed to the Apollo program, which was grounded on a minimum three man crew and minimum 10,000 pound command module weight.
At a cost of 5% of the Apollo project, NASA staged twelve flights, ten of them manned, in the course of which the problems of rendezvous, docking, and learning how to do work in a spacesuit in zero-G were tackled and solved. It is said that not much of this was fed back to Apollo, since the two projects had completely different sets of contractors and there was little cross-fertilisation in the rendezvous and docking areas. But it is undeniable that important issues in regard to working in zero-G were discovered and solved and both flight and ground crews gained experience that would make the Apollo flights successful.
|Gemini6 in orbit - Gemini6 in orbit view j|
Credit: NASA. 16,563 bytes. 288 x 222 pixels.
Major Events: .
DeMarquis D. Wyatt, Assistant to the Director of Space Flight Development, testified before Congress in support of NASA's request for $3 million in Fiscal Year 1960 for research on techniques and problems of space rendezvous. Wyatt explained that logistic support for a manned space laboratory, a possible post-Mercury flight program, depended upon resolving several key problems and making rendezvous in orbit practical. Among key problems he cited were establishment of methods for fixing the relative positions of two objects in space; development of accurate target acquisition devices to enable supply craft to locate the space station; development of guidance systems to permit precise determination of flight paths; and development of reliable propulsion systems for maneuvering in orbit.
H. Kurt Strass of Space Task Group's Flight Systems Division (FSD) recommended the establishment of a committee to consider the preliminary design of a two-man space laboratory. Representatives from each of the specialist groups within FSD would work with a special projects group, the work to culminate in a set of design specifications for the two-man Mercury.
|Gemini6 in orbit - Gemini6 in orbit view g|
Credit: NASA. 23,176 bytes. 522 x 320 pixels.
Space Task Group management held a Capsule Review Board meeting. The first topic on the agenda was a follow-on Mercury program. Several types of missions were considered, including long-duration, rendezvous, artificial gravity, and flight tests of advanced equipment. Major conclusion was that a follow-on program needed to be specified in greater detail.
McDonnell had been studying the concept of a maneuverable Mercury spacecraft since 1959. On February 1, Space Task Group (STG) Director Robert R. Gilruth assigned James A. Chamberlin, Chief, STG Engineering Division, who had been working with McDonnell on Mercury for more than a year, to institute studies with McDonnell on improving Mercury for future manned space flight programs.
First formal NASA/McDonnell discussions on Mercury Mark II (Gemini).
|Gemini6 in orbit - Gemini6 in orbit view e|
Credit: NASA. 13,559 bytes. 260 x 247 pixels.
Martin Company personnel briefed NASA officials in Washington, D.C., on the Titan II weapon system. Albert C. Hall of Martin had contacted NASA's Associate Administrator, Robert C. Seamans, Jr., on April 7 to propose the Titan II as a launch vehicle for a lunar landing program. Although skeptical, Seamans nevertheless arranged for a more formal presentation. Abe Silverstein, NASA Director, Office of Space Flight Programs, was sufficiently impressed by the Martin briefing to ask Director Robert R. Gilruth and Space Task Group to study possible Titan II uses. Silverstein shortly informed Seamans of the possibility of using the Titan II to launch a scaled-up Mercury spacecraft.
|Gemini 6 in orbit - Gemini 6 in orbit view d|
Credit: NASA. 21,641 bytes. 562 x 321 pixels.
Baseline 10 earth orbit flights; also proposed for docking with Centaur and circumlunar flights by March 1965. NASA not interested - threat to Apollo.
John C. Houbolt of Langley Research Center made a presentation to STG on rendezvous and the lunar orbit rendezvous plan. At this time James A. Chamberlin of STG requested copies of all of Houbolt's material because of the pertinence of this work to the Mercury Mark II program and other programs then under consideration.
|Gemini6 in orbit - Gemini6 in orbit view i|
Credit: NASA. 43,735 bytes. 511 x 443 pixels.
D. Brainerd Holmes, NASA Director of Manned Space Flight, outlined the preliminary project development plan for the Mercury Mark II program in a memorandum to NASA Associate Administrator Robert C. Seamans, Jr. The primary objective of the program was to develop rendezvous techniques; important secondary objectives were long-duration flights, controlled land recovery, and astronaut training. The development of rendezvous capability, Holmes stated, was essential:
|Gemini6 in orbit - Gemini6 in orbit view f|
Credit: NASA. 20,584 bytes. 488 x 355 pixels.
NASA Associate Administrator Robert C. Seamans, Jr., and DOD Deputy Director of Defense Research and Engineering John H. Rubel recommended to Secretary of Defense Robert S. McNamara and NASA Administrator James E. Webb that detailed arrangements for support of the Mercury Mark II spacecraft and the Atlas-Agena vehicle used in rendezvous experiments be planned directly between NASA's Office of Manned Space Flight and the Air Force and other DOD organizations. NASA's primary responsibilities would be the overall management and direction for the Mercury Mark II/ Agena rendezvous development and experiments. The Air Force responsibilities would include acting as NASA contractor for the Titan II launch vehicle and for the Atlas-Agena vehicle to be used in rendezvous experiments. DOD's responsibilities would include assistance in the provision and selection of astronauts and the provision of launch, range, and recovery support, as required by NASA.
In Houston, Director Robert R. Gilruth of Manned Spacecraft Center announced plans to develop a two-man Mercury capsule. Built by McDonnell, it would be similar in shape to the Mercury capsule but slightly larger and from two to three times heavier. Its booster would be a modified Titan II. A major program objective would be orbital rendezvous. The two-man spacecraft would be launched into orbit and would attempt to rendezvous with an Agena stage put into orbit by an Atlas. Total cost of 12 capsules plus boosters and other equipment was estimated at $500 million. The two-man flight program would begin in the 1963-1964 period with several unmanned ballistic flights to test overall booster-spacecraft compatibility and system engineering. Several manned orbital flights would follow. Besides rendezvous flybys of the target vehicle, actual docking missions would be attempted in final flights. The spacecraft would be capable of missions of a week or more to train pilots for future long-duration circumlunar and lunar landing flights. The Mercury astronauts would serve as pilots for the program, but additional crew members might be phased in during the latter portions of the program.
|Gemini Control Panel - Control panel of the basic Gemini (454 x 383 pixel image).|
Credit: NASA. 42,640 bytes. 454 x 383 pixels.
Plans for the development of a two-man Mercury spacecraft were announced by Robert R. Gilruth, MSC Director. The two-man spacecraft, to be built by McDonnell Aircraft Corporation, would be similar in shape to the Mercury spacecraft but slightly larger and two to three times heavier. Its booster rocket would be a modified Air Force Titan II, scheduled for flight test in early 1962. One of the major objectives in the program would be a test of orbital rendezvous, in which the two-man spacecraft would be launched into orbit by the Titan II and attempt to rendezvous with an Agena stage launched by an Atlas rocket. The total cost for a dozen two-man spacecraft plus boosters and other equipment was estimated at $500 million.
McDonnell given letter contract for development of Gemini.
Titan II, an advanced ICBM and the booster designated for NASA's two-man orbital flights, was successfully captive-fired for the first time at the Martin Co.'s Denver facilities. The test not only tested the flight vehicle but the checkout and launch equipment intended for operational use.
|Gemini Control Panel - Gemini control panel - closeup of the pedestal controls between the two astronauts.|
Credit: NASA. 79,207 bytes. 685 x 617 pixels.
The name had been suggested by Alex P. Nagy of NASA Headquarters because the twin stars Castor and Pollux in constellation Gemini (the Twins) seemed to him to symbolize the program's two-man crew, its rendezvous mission, and its relation to Mercury. Coincidentally, the astronomical symbol (II) for Gemini, the third constellation of the zodiac, corresponded neatly to the Mark II designation.
Director Robert R. Gilruth of Manned Spacecraft Center (MSC) appointed James A. Chamberlin, Chief of Engineering Division, as Manager of Gemini Project Office (GPO). The next day MSC advised McDonnell, by amendment No. 1 to letter contract NAS 9-170, that GPO had been established. It was responsible for planning and directing all technical activities and all contractor activities within the scope of the contract.
Following receipt of the program go-ahead on December 22, 1961, McDonnell began defining the Gemini spacecraft. At that time, the basic configuration was already firm. During the three-month period, McDonnell wrote a series of detailed specifications to define the overall vehicle, its performance, and each of the major subsystems. These were submitted to NASA and approved. During the same period, the major subsystems specification control drawings - the specifications against which equipment was procured - were written, negotiated with NASA, and distributed to potential subcontractors for bid.
|Gemini Control Panel - Gemini Control Panel - closeup of the command astronaut (left hand seat) controls.|
Credit: NASA. 96,192 bytes. 686 x 846 pixels.
James E. Webb, NASA's new Administrator, reviewed the Gemini program. Project Gemini cost estimates at this point ($744.3 million) had increased substantially over the original estimate of $250 million. Estimated spacecraft cost had risen from $240.5 to $391.6 million; Titan II cost, from $113.0 to $161.8 million; Atlas-Agena, from $88.0 to $106.3 million; and supporting development (including the paraglider program), from $29.0 to $36.8 million. Estimated operations costs had declined from $59.0 to $47.8 million.
North American began flight tests of the half-scale vehicle (HSTV) in Phase II-A of the Paraglider Development Program two months behind schedule. The instrumented HSTV with the paraglider predeployed was towed aloft by helicopter. Objectives of the predeployed flights were to evaluate flight performance, longitudinal and lateral control characteristics, effectiveness of control, and the flare maneuver capability of the paraglider. Despite various minor malfunctions in all five test flights (August 14, 17, 23, September 17, and October 23, 1962), test results verified the stability of the wing/vehicle combination in free flight and the adequacy of control effectiveness.
|Gemini Control Panel - Gemini Control Panel - closeup of the second astronaut (right hand side) controls.|
Credit: NASA. 85,400 bytes. 675 x 697 pixels.
NASA's nine new astronauts were named in Houston, Tex., by Robert R. Gilruth, MSC Director. Chosen from 253 applicants, the former test pilots who would join the original seven Mercury astronauts in training for Projects Gemini and Apollo were: Neil A. Armstrong, NASA civilian test pilot; Maj. Frank Borman, Air Force; Lt. Charles Conrad, Jr., Navy; Lt.Cdr. James A, Lovell, Jr., Navy; Capt. James A. McDivitt, Air Force; Elliot M. See, Jr., civilian test pilot for the General Electric Company; Capt. Thomas P. Stafford, Air Force; Capt. Edward H. White II, Air Force; and Lt. Cdr. John W. Young, Navy.
McDonnell and Lockheed reported on radiation hazards and constraints for Gemini missions at a Trajectories and Orbits Coordination meeting. McDonnell's preliminary findings indicated no radiation hazard for normal Gemini operations with some shielding; with no shielding the only constraint was on the 14-day mission, which would have to be limited to an altitude of 115 nautical miles. Lockheed warned that solar flares would pose a problem at higher altitudes. Lockheed also recommended limiting operations to under 300 miles pending more data on the new radiation belts created by the Atomic Energy Commission's Project Dominic in July 1962.
|Gemini Control Panel - Gemini Control Panel - closeup of the center panel and overhead controls.|
Credit: NASA. 119,581 bytes. 529 x 927 pixels.
Simulated off-the-pad ejection test No. 8 was conducted at Naval Ordnance Test Station. Two dummies were ejected, and for the first time the test incorporated a ballute system. The ballute (for balloon + parachute) had been introduced as a device to stabilize the astronaut after ejection at high altitudes. Ejection seat and dummy separated satisfactorily and the personnel parachute deployed properly; but faults in the test equipment prevented the canopy from fully inflating. The ballute failed to inflate or release properly on either dummy. As a result, the parachute was redesigned to ensure more positive inflation at very low dynamic pressures. The redesigned chute was tested in a series of five entirely successful dummy drops during March.
Colonel Kenneth W Schultz of Headquarters, Air Force Office of Development Planning, outlined Department of Defense objectives in the Gemini program at the first meeting of the Gemini Program Planning Board. He defined three general objectives: conducting orbital experiments related to such possible future missions as the inspection and interception of both cooperative and passive or noncooperative objects in space under a variety of conditions, logistic support of a manned orbiting laboratory, and photo reconnaissance from orbit; gaining military experience and training in all aspects of manned space flight; and assessing the relationship between man and machine in the areas of potential military missions.
|Gemini Advanced - More advanced versions of Gemini proposed by McDonnell Douglas as a follow-on to the basic program (927 x 723 pixel version).|
Credit: McDonnell Douglas. 44,467 bytes. 872 x 745 pixels.
First West Coast launch of a Titan 2 ICBM from an underground silo.
James A Chamberlin was reassigned from Manager of Project Gemini to Senior Engineering Advisor to Robert R Gilruth, Director of Manned Spacecraft Center. Charles W Mathews was reassigned from Chief, Spacecraft Technology Division, to Acting Manager of Project Gemini.
A contract for $33,797,565, including fixed fee, was signed with Philco Corporation, Philadelphia, Pennysylvania, to implement the Integrated Mission Control Center. Philco would provide all the flight information and control display equipment except the real-time computer complex, which was to be built and maintained by International Business Machines Corporation. Philco would also assist Manned Spacecraft Center in maintaining and operating the equipment for at least one year after acceptance. Philco had been selected from seven qualified bidders, and final contract negotiations had begun February 25, 1963.
|Gemini Transport - Gemini Transport version proposed as a Gemini program follow-on. With the extended reentry module, this is the ancestor of the Big Gemini spacecraft proposed in the late 1960's.|
Credit: McDonnell Douglas. 10,124 bytes. 371 x 261 pixels.
In a NASA position paper, stimulated by Secretary of Defense McNamara's testimony on the fiscal year 1964 budget and an article in Missiles and Rockets interpreting his statements, Robert C. Seamans, Jr., NASA Associate Administrator, stressed NASA's primary management responsibility in the Gemini program. McNamara's remarks had been interpreted as presaging an Air Force take-over of Project Gemini. Seamans recognized the vital role of the Department of Defense in Gemini management and operations but insisted that NASA had the final and overall responsibility for program success.
Sled test No. 2, the first dynamic dual-ejection test of the Gemini escape system, was run at China Lake. Both seats ejected and all systems functioned properly. The test was scheduled to be rerun, however, because the sled failed to attain high enough velocity. The purpose of sled tests in the ejection seat development program was to simulate various high-altitude abort situations. Sled test No. 3 was successfully run on August 9. Further tests were delayed while the ejection system was being redesigned. A modified egress kit was tested in two dummy drops on December 12, with no problems indicated. Gemini Project Office directed McDonnell to proceed with plans for the next sled test. Developmental sled testing on the escape system, incorporating the redesigned egress kit and a soft survival pack, resumed on January 16, 1964, with test No. 4; all systems functioned normally. Test No. 5, the planned repetition of test No. 2, brought developmental sled testing to an end on February 7.
|Gemini Control Panel - Control panel of the basic Gemini (903 x 765 pixel image).|
Credit: NASA. 146,321 bytes. 903 x 765 pixels.
Gemini Project Office (GPO) reported that it was investigating the use of a parasail and landing rocket system to enable the Gemini spacecraft to make land landings. Major system components were the parasail, drogue parachute, retrorocket, control system, and landing rocket. Unlike the conventional parachute, the parasail was capable of controlled gliding and turning. Landing rockets, fired just before touchdown, reduced the spacecraft terminate rate of descent to between 8 and 11 feet per second. Research and development testing was being conducted by the Landing and Impact System Section of Systems Evaluation and Development Division at Manned Spacecraft Center, while McDonnell had just completed a limited study of the advantages and disadvantages, including time required, of incorporating the new landing system on the spacecraft. GPO briefed NASA Headquarters on the system September 6, when it was decided that no further action would be taken on the parasail.
After a receiving inspection (October 7) and Voltage Standing Wave Ratio Test (October 8), its instrument pallets were removed for laboratory test and checkout (October 9) while the spacecraft was being checked out, weighed, and balanced. Instrument pallets were reinstalled November 26. Individual and integrated communications, instrumentation, and environmental control systems were then performed. Final industrial area testing of the spacecraft concluded with a confidence level test on February 12, 1964.
|Gemini Variants - Modest modifications of Gemini proposed by McDonnell Douglas as a follow-on to the basic program (927 x 723 pixel version).|
Credit: McDonnell Douglas. 43,356 bytes. 927 x 723 pixels.
The contract called for 20 tests to demonstrate deployment of the full-scale wing from the rendezvous and recovery can, followed by glide and radio-controlled maneuvering; each test was to be terminated by release of the wing and recovery by the emergency parachute system (which had been qualified on December 3, 1963).
George E. Mueller, NASA Associate Administrator for Manned Space Flight, informed the staff of the Gemini Project Office (GPO) that all 12 Gemini flights would end in water landings, although Project Gemini Quarterly Report No. 8 for the period ending February 29, 1964, still listed the paraglider for the last three Gemini missions.
The boilerplate achieved a horizontal velocity of 60 feet per second and a vertical velocity of about 40 feet per second at the time of impact with the water. The test was conducted to obtain data on landing accelerations for various speeds and attitudes of the spacecraft.
Credit: McDonnell Douglas. 13,879 bytes. 286 x 318 pixels.
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.
|Gemini preflight - Gemini spacecraft being prepared in the shop.|
Credit: NASA. 42,452 bytes. 395 x 480 pixels.
Simulated flight missions were carried out over nine days and invloved Goddard Space Flight Center, Mission Control Center at the Cape, and eight remote sites in the worldwide network to test tracking and communications equipment, as well as flight control procedures and equipment. This completed the updating of the Manned Space Flight Tracking Network to support the Gemini flights. Converting the Mercury network for Gemini had taken two years and cost $50 million.
The second Gemini mission, an unmanned suborbital flight designated Gemini-Titan 2 (GT-2), was successfully launched from complex 19 at Cape Kennedy at 9:04 a.m., e.s.t. Major objectives of this mission were to demonstrate the adequacy of the spacecraft reentry module's heat protection during a maximum-heating-rate reentry, the structural integrity of the spacecraft from liftoff through reentry, and the satisfactory performance of spacecraft systems. Secondary objectives included obtaining test results on communications, cryogenics, fuel cell and reactant supply system, and further qualification of the launch vehicle. All objectives were achieved, with one exception: no fuel cell test results were obtained because the system malfunctioned before liftoff and was deactivated. GT-2 was a suborbital ballistic flight which reached a maximum altitude of 92.4 nautical miles. Retrorockets fired 6 minutes 54 seconds after launch, and the spacecraft landed in the Atlantic Ocean 11 minutes 22 seconds later - 1848 nautical miles southeast of the launch site. Full duration of the mission was 18 minutes 16 seconds. The primary recovery ship, the aircraft carrier Lake Champlain, picked up the spacecraft at 10:52 a.m., e.s.t.
Credit: © Mark Wade. 4,678 bytes. 205 x 405 pixels.
First manned test flight of Gemini. Virgil I. Grissom and John W. Young entered an elliptical orbit about the earth. After three orbits, the pair manually landed their spacecraft in the Atlantic Ocean, thus performing the first controlled reentry. Unfortunately, they landed much farther from the landing zone than anticipated, about 97 km (60 miles) from the aircraft carrier U.S.S. Intrepid. But otherwise the mission was highly successful. Gemini III, America's first two-manned space mission, also was the first manned vehicle that was maneuverable. Grissom used the vehicle's maneuvering rockets to effect orbital and plane changes. Grissom wanted to name the spacecraft 'Molly Brown' (as in the Unsinkable, a Debbie Reynolds/Howard Keel screen musical). NASA was not amused and stopped allowing the astronauts to name their spacecraft (until forced to when having two spacecraft aloft at once during the Apollo missions). The flight by Young was the first of an astronaut outside of the original seven. Young, who created a media flap by taking a corned beef sandwich aboard as a prank, would go on to fly to the moon on Apollo and the Space Shuttle on its first flight sixteen years later.
|Gemini 6 3 - View of Gemini 6 during the Gemini 6 and 7 first space rendeavous.|
Credit: NASA. 14,848 bytes. 421 x 446 pixels.
|Gemini-Agena - Gemini docked to Agena|
Credit: © Mark Wade. 3,073 bytes. 460 x 140 pixels.
First American walk in space; tested spacesuit and ability to manoeuvre.
Radar Evaluation Pod.
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.
|Gemini 2 view|
Credit: © Mark Wade. 9,689 bytes. 423 x 462 pixels.
Primary objectives of the mission were demonstrating manned orbital flight for approximately 14 days and evaluating the physiological effects of a long-duration flight on the crew. Among the secondary objectives were providing a rendezvous target for the Gemini VI-A spacecraft, stationkeeping with the second stage of the launch vehicle and with spacecraft No. 6, conducting 20 experiments, using lightweight pressure suits, and evaluating the spacecraft reentry guidance capability. All objectives were successfully achieved with the exception of two experiments lost because of equipment failure. Shortly after separation from the launch vehicle, the crew maneuvered the spacecraft to within 60 feet of the second stage and stationkept for about 15 minutes. The exercise was terminated by a separation maneuver, and the spacecraft was powered down in preparation for the 14-day mission. The crew performed five maneuvers during the course of the mission to increase orbital lifetime and place the spacecraft in proper orbit for rendezvous with spacecraft No. 6. Rendezvous was successfully accomplished during the 11th day in orbit, with spacecraft No. 7 serving as a passive target for spacecraft No. 6. About 45 hours into the mission, Lovell removed his pressure suit. He again donned his suit at 148 hours, while Borman removed his. Some 20 hours later Lovell again removed his suit, and both crewmen flew the remainder of the mission without suits, except for the rendezvous and reentry phases. With three exceptions, the spacecraft and its systems performed nominally throughout the entire mission. The delayed-time telemetry playback tape recorder malfunctioned about 201hours after liftoff, resulting in the loss of all delayed-time telemetry data for the remainder of the mission. Two fuel cell stacks showed excessive degradation late in the flight and were taken off the line; the remaining four stacks furnished adequate electrical power until reentry. Two attitude thrusters performed poorly after 283 hours in the mission. Retrofire occurred exactly on time, and reentry and landing were nominal. The spacecraft missed the planned landing point by only 10.3 km miles, touching down on December 18. The crew arrived at the prime recovery ship, the aircraft carrier Wasp, half an hour later. The spacecraft was recovered half an hour after the crew.
Credit: © Mark Wade. 797 bytes. 155 x 70 pixels.
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 - View of Gemini 6 during the Gemini 6 and 7 first space rendeavous.|
Credit: NASA. 13,597 bytes. 256 x 237 pixels.
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.
The Atlas-Agena target vehicle for the Gemini VIII mission was successfully launched from KSC Launch Complex 14 at 10 a.m. EST March 16. The Gemini VIII spacecraft followed from Launch Complex 19 at 11:41 a.m., with command pilot Neil A. Armstrong and pilot David R. Scott aboard. The spacecraft and its target vehicle rendezvoused and docked, with docking confirmed 6 hours 33 minutes after the spacecraft was launched. This first successful docking with an Agena target vehicle was followed by a major space emergency. About 27 minutes later the spacecraft-Agena combination encountered unexpected roll and yaw motion. A stuck thruster on Gemini put the docked assembly into a wild high speed gyration. Near structural limits and blackout, Armstrong undocked, figuring the problem was in the Agena, which only made it worse. The problem arose again and when the yaw and roll rates became too high the crew shut the main Gemini reaction control system down and activated and used both rings of the reentry control system to reduce the spacecraft rates to zero. This used 75% of that system's fuel. Although the crew wanted to press on with the mission and Scott's planned space walk, ground control ordered an emergency splashdown in the western Pacific during the seventh revolution. The spacecraft landed at 10:23 p.m. EST March 16 and Armstrong and Scott were picked up by the destroyer U.S.S. Mason at 1:37 a.m. EST March 17. Although the flight was cut short by the incident, one of the primary objectives - rendezvous and docking (the first rendezvous of two spacecraft in orbital flight) - was accomplished.
Credit: © Mark Wade. 1,025 bytes. 149 x 156 pixels.
|Mercury Gemini - Comparison of the Mercury and Gemini capsules.|
Credit: © Mark Wade. 6,253 bytes. 399 x 415 pixels.
Target vehicle for Gemini 8.
The ATDA achieved a near-circular orbit (apogee 161.5, perigee 158.5 nautical miles). One hour and 40 minutes later, the scheduled launch of Gemini IX-A was postponed by a ground equipment failure which prevented the transfer of updating information from Cape Kennedy mission control center to the spacecraft computer. The mission was recycled for launch on June 3, following a prepared 48-hour recycle plan. Anomalous telemetry indicated some sort of problem with the target, but it was not until Gemini IX rendezvoused with it in orbit that it was seen that fairing separation had failed.
Elliot See and Charlie Bassett were the prime crew for Gemini 9. On February 28, 1966, they were flying in a NASA T-38 trainer to visit the McDonnell plant in St Louis, where their spacecraft was in assembly. See misjudged his landing approach, and in pulling up from the runway hit Building 101 where the spacecraft was being assembled. Both astronauts were killed, and 14 persons on the ground were injured. As a result, the Gemini 9 backup crew became the prime crew, and all subsequent crew assignments were reshuffled. This ended up determining who would be the first man on the moon....
At the first launch attempt, while the crew waited buttoned up in the spacecraft on the pad, their Agena docking target field blew up on the way to orbit. NASA decided to use an Atlas to launch an Agena docking collar only. This was called the Augmented Target Docking Adapter. Ths was successfully launched and the Gemini succeeded in rendezvousing with it. However, the ATDA shroud had not completely separated, thus making docking impossible. However three different types of rendezvous were tested with the ATDA. Cernan began his EVA, which was to include flight with a USAF MMU rocket pack but the Gemini suit could not handle heat load of the astronaut's exertions. Cernan's faceplate fogs up, forcing him to blindly grope back into the Gemini hatch after only two hours.
Seventh manned and third rendezvous mission of the Gemini program. Major objectives of the mission were to rendezvous and dock with the augmented target docking adapter (ATDA) and to conduct extravehicular activities (EVA). These objectives were only partially met. After successfully achieving rendezvous during the third revolution - a secondary objective - the crew discovered that the ATDA shroud had failed to separate, precluding docking - a primary objective - as well as docking practice - another secondary objective. The crew was able, however, to achieve other secondary objectives: an equi-period rendezvous, using onboard optical techniques and completed at 6 hours 36 minutes ground elapsed time; and a rendezvous from above, simulating the rendezvous of an Apollo command module with a lunar module in a lower orbit (completed at 21 hours 42 minutes ground elapsed time). Final separation maneuver was performed at 22 hours 59 minutes after liftoff. EVA was postponed because of crew fatigue, and the second day was given over to experiments. The hatch was opened for EVA at 49 hours 23 minutes ground elapsed time. EVA was successful, but one secondary objective - evaluation of the astronaut maneuvering unit (AMU) - was not achieved because Cernan's visor began fogging. The extravehicular life support system apparently became overloaded with moisture when Cernan had to work harder than anticipated to prepare the AMU for donning. Cernan reentered the spacecraft, and the hatch was closed at 51 hours 28 minutes into the flight. The rest of the third day was spent on experiments. Following the third sleep period, the crew prepared for retrofire, which was initiated during the 45th revolution. The spacecraft landed within a mile of the primary recovery ship, the aircraft carrier Wasp. The crew remained with the spacecraft, which was hoisted aboard 53 minutes after landing.
Attempted to test USAF Astronaut Manoeuvring Unit. Cancelled when Cernan's faceplate fogged over.
Exciting mission with successful docking with Agena, flight up to parking orbit where Gemini 8 Agena is stored. Collins space walks from Gemini to Agena to retrieve micrometeorite package left in space all those months. Loses grip first time, and tumbles head over heels at end of umbilical around Gemini. Package retrieved on second try.
The Gemini X mission began with the launch of the Gemini Atlas-Agena target vehicle from complex 14. The Gemini Agena target vehicle (GATV) attained a near-circular, 162- by 157-nautical-mile orbit. Spacecraft No. 10 was inserted into a 145- by 86-nautical-mile elliptical orbit. Slant range between the two vehicles was very close to the nominal 1000 miles. Major objective of the mission was achieved during the fourth revolution when the spacecraft rendezvoused with the GATV at 5 hours 23 minutes ground elapsed time and docked with it about 30 minutes later. More spacecraft propellant was used to achieve rendezvous than had been predicted, imposing constraints on the remainder of the mission and requiring the development of an alternate flight plan. As a result, several experiments were not completed, and another secondary objective - docking practice - was not attempted. To conserve fuel and permit remaining objectives to be met, the spacecraft remained docked with the GATV for about 39 hours. During this period, a bending mode test was conducted to determine the dynamics of the docked vehicles, standup extravehicular activties (EVA) were conducted, and several experiments were performed. The GATV primary and secondary propulsion systems were used for six maneuvers to put the docked spacecraft into position for rendezvous with the Gemini VIII GATV as a passive target. The spacecraft undocked at 44 hours 40 minutes ground elapsed time, separated from the GATV, and used its own thrusters to complete the second rendezvous some three hours later. At 48 hours and 42 minutes into the flight, a 39-minute period of umbilical EVA began, which included the retrieval of a micrometorite collection package from the Gemini VIII Agena. The hatch was opened a third time about an hour later to jettison extraneous equipment before reentry. After about three hours of stationkeeping, the spacecraft separated from the GATV. At 51 hours 39 minutes ground elapsed time, the crew performed a true anomaly-adjust maneuver to minimize reentry dispersions resulting from the retrofire maneuver. The retrofire maneuver was initiated at 70 hours 10 minutes after liftoff, during the 43rd revolution. The spacecraft landed within sight of the prime recovery ship, the aircraft carrier Guadalcanal, some 5 km from the planned landing point on July 21.
Space craft engaged in investigation of spaceflight techniques and technology (US Cat A).
Photographed earth and stars.
Retrieved micrometeoroid collector from Agena.
Threw excess equipment out of spacecraft.
More highjinks with Conrad. First orbit docking with Agena, followed by boost up to record 800 km orbit, providing first manned views of earth as sphere. Tether attached by Gordon to Agena in spacewalk and after a lot of effort tethered spacecraft put into slow rotation, creating first artificial microgravity.
The primary objective of the Gemini XI mission was to rendezvous with the Gemini Agena target vehicle (GATV) during the first revolution and dock. Five maneuvers completed the spacecraft/GATV rendezvous at 1 hour 25 minutes ground elapsed time, and the two vehicles docked nine minutes later. Secondary objectives included docking practice, extravehicular activity (EVA), 11 experiments, docked maneuvers, a tethered vehicle test, demonstrating automatic reentry, and parking the GATV. All objectives were achieved except one experiment - evaluation of the minimum reaction power tool - which was not performed because umbilical EVA was terminated prematurely. Umbilical EVA began at 24 hours 2 minutes ground elapsed time and ended 33 minutes later. Gordon became fatigued while attaching the tether from the GATV to the spacecraft docking bar. An hour later the hatch was opened to jettison equipment no longer required. At 40 hours 30 minutes after liftoff, the GATV primary propulsion system (PPS) was fired to raise the apogee of the docked vehicles to 741 nautical miles for two revolutions. The PPS was fired again, 3 hours 23 minutes later, to reduce apogee to 164 nautical miles. The crew then prepared for standup EVA, which began at 47 hours 7 minutes into the flight and lasted 2 hours 8 minutes. The spacecraft was then undocked to begin the tether evaluation. At 50 hours 13 minutes ground elapsed time, the crew initiated rotation. Initial oscillations damped out and the combination became very stable after about 20 minutes; the rotational rate was then increased. Again, initial oscillations gradually damped out and the combination stabilized. At about 53 hours into the mission, the crew released the tether, separated from the GATV, and maneuvered the spacecraft to an identical orbit with the target vehicle. A fuel cell stack failed at 54 hours 31 minutes, but the remaining five stacks shared the load and operated satisfactorily. A rerendezvous was accomplished at 66 hours 40 minutes ground elapsed time, and the crew then prepared for reentry. The spacecraft landed less than 5 km from the planned landing point at 71 hours 17 minutes after liftoff. The crew was retrieved by helicopter, and the spacecraft was brought aboard the prime recovery ship, the aircraft carrier Guam, about an hour after landing.
Docking target for Gemini 11.
Retrieved micrometeoroid collector from Agena.
Threw excess equipment out of spacecraft.
Photographed earth and stars.
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. Retrofire occurred 94 hours after liftoff. Reentry was automatically controlled. The spacecraft landed less than 5 km from the planned landing point on November 15. The crew was picked up by helicopter and deposited 28 minutes later on the deck of the prime recovery ship, the aircraft carrier Wasp. The spacecraft was recovered 67 minutes after landing.
Docking target for Gemini 12.
Photographed earth and stars.
Tested tools and techniques for extravehicular activity.
Photographed earth limb and stars in ultraviolet.