Gemini 7: Two Weeks in the Front Seat of a Volkswagen

With the crew of the International Space Station (ISS) routinely spending six or more months in orbit, it is sometimes forgotten that only a few decades ago the first flights of such length were just being attempted and their effects on the human body were largely unknown. It has taken over a half a century of experience to develop the techniques needed for people to remain healthy and productive in space for months at a time as well as adapt to Earth’s environment after returning.

During the opening decade of the Space Age, NASA tasked its Gemini program to perform a series of long duration missions of increasing length to determine if a crew could perform adequately over the anticipated time needed for Apollo to perform a mission to the Moon. The ultimate long duration mission was that of Gemini 7 launched in December 1965 with its crew of two spending a then record-setting two weeks in orbit. While only a fraction of the length of today’s tours on the ISS with its large internal volume and many facilities, the Gemini 7 mission pushed the limits of what was then known. And with its very limited internal volume, the press at the time likened this mission to spending two weeks in the front seat of a Volkswagen Beetle.

A promotional image from 1965 of the Volkswagen Beetle. (VW)

 

Gemini Program Objectives

The purpose of NASA’s Gemini program was to develop the technologies and techniques needed to fulfill President Kennedy’s goal of landing a man on the Moon by 1970. The major objectives of the program were:

– Demonstrate that humans and their equipment can survive up to two weeks in space
– Demonstrate rendezvous and docking techniques in orbit
– Demonstrate the technology and techniques needed to perform EVAs (Extra-Vehicular Activities)

Meeting all of these objectives was necessary if the Apollo lunar program were to be successful.

Diagram showing the major systems of the Gemini spacecraft. Click on image to enlarge. (McDonnell)

Gemini was a two-man spacecraft that was roughly conical in shape with a base diameter of 3.3 meters which stood 5.8 meters tall.  Built by the McDonnell Aircraft Corporation (which merged with Douglas in 1967 to become McDonnell Douglas which subsequently merged with Boeing 30 years later), it consisted of two major sections. The first section was the reentry module which housed the crew, their equipment, food supplies and so on in orbit as well as the recovery systems needed to safely return them to Earth. Unlike today’s crewed spacecraft, the Gemini crew cabin was pressurized with pure oxygen at about one-third standard atmospheric pressure to save weight. The next section, the adapter section, connected the reentry module to the launch vehicle during ascent and housed equipment needed to support the crew while in orbit. It consisted of a retrograde section which held a set of four solid retrorockets used to start the descent to Earth from orbit and an equipment section which housed the in-orbit propulsion systems, life support, power systems and all other equipment not needed for the return to Earth.

With a typical launch mass of up to about 3,700 kilograms or more, Gemini needed the largest operational rocket available at the time to get into orbit: a modified Titan II ICBM built by Martin Marietta (which is now part of Lockheed Martin). A number of modifications were made to simplify the operation of this rocket, smooth out its ride and improve its reliability to support crewed missions. With the Gemini spacecraft mounted on top, the Titan II GLV (Gemini Launch Vehicle) was 33 meters tall and had a fully fueled launch mass of about 154 metric tons.

Diagram showing the major components of the Gemini-Titan II. Click on image to enlarge (NASA)

After the first successful crewed test flight of the spacecraft during the brief three-orbit Gemini 3 mission launched on March 23, 1965, NASA was ready to work its way steadily up the learning curve to meet the Gemini program’s objectives (see “The Mission of Gemini 3”). The primary objective of the second crewed flight, Gemini 4 launched on June 3, was to start the step-wise process of increasing the duration of crewed missions by spending four days in orbit (see “The Forgotten Mission of Gemini 4”). With the flight of Gemini 5, the mission duration had been extended to eight days – the minimum time necessary for Apollo to land on the Moon and return to Earth (see “Eight Days or Bust: The Mission of Gemini 5”). While the primary objective of the two-day Gemini 6 mission was to perform the first orbital rendezvous and docking, officials left reaching the ultimate Gemini program goal of spending two weeks in orbit to the Gemini 7 mission.

 

The Gemini 7 Mission

The primary objective of the Gemini 7 mission was to evaluate the effects on the crew and spacecraft of 330 hours in orbit. Secondary objectives included conducting 20 medical, science and engineering experiments ranging from assessing various aspects of crew health during a long duration mission to photography of the Earth and interesting weather phenomena from orbit. Immediately after reaching orbit, Gemini 7 would perform station keeping maneuvers with the spent second stage of their Titan II launch vehicle with the secondary objective of gaining more experience in these important operations. Other secondary objectives included conducting various spacecraft systems tests as well as an attempt at a precision reentry and landing.

A fish-eye view of the Gemini 7 crew cabin. (NASA)

Because of the length of this mission, it was felt that the standard G4C space suits worn on the earlier Gemini missions would prove to be too uncomfortable. Another secondary objective of the Gemini 7 mission was to evaluate the new lightweight G5C spacesuit. Designed and manufactured by the David Clark Company, development of the G5C suit had started in April 1965. It dispensed with as many of the hard parts in the G4C suit as was possible and consisted of only two nylon-based layers to get the garment’s mass down to 7.2 kilograms. Like the Sokol spacesuit used today on Soyuz flights, the G5C suit had no hard helmet. Instead it had a nylon hood with a clear visor integrated with the suit that could be easily unzipped to open. To protect their heads during key parts of the flight, the astronauts would wear modified pilot’s helmets inside their suits with built in headphones and a microphone for communications.

The crew of the Gemini 7 mission wore the new lightweight G5C spacesuits during their mission like he one being modeled here. (NASA)

The new suits were designed so that it could be partially doffed during flight for comfort and take only 35 seconds to close up in an emergency. It was also designed to be completely removed while in orbit and be donned in five to ten minutes. As a safety precaution, mission planners would allow only one astronaut at a time to remove his spacesuit and wear just lightweight undergarments. This would be the first time an American astronaut would go without a spacesuit while in orbit, although the three cosmonauts on the Voskhod 1 mission back in October 1964 flew their entire one-day mission without spacesuits (see “The Mission of Voskhod 1”). The two astronauts would alternate removing their suits during the 14-day mission and both would be required to wear the G5C suit during critical phases of the mission such as launch and reentry.

Portrait of the prime crew for the Gemini 7 mission: James A. Lovell, Jr. (left) as pilot and Frank Borman (right) as command pilot. (NASA)

In order to take advantage of their already extensive training, the backup crew of the Gemini 4 long-duration flight were assigned to fly the Gemini 7 mission. The command pilot, 37-year old USAF Major Frank Borman, was a West Point graduate with extensive experience as a pilot and instructor in thermodynamics, fluid mechanics as well as flight and spacecraft testing. The pilot for this mission, 37-year old USN Lt. Commander James A. Lovell, Jr., was an Annapolis graduate with an equally impressive military career as a pilot and instructor. Both men were part of the second group of NASA astronauts selected in September 1962 and neither had flown into space before (see “NASA Selects the “New Nine” – September 17, 1962“). Borman and Lovell’s back up crew consisted of USAF Major Edward H. White II, who was the pilot on the four-day Gemini 4 mission, and rookie astronaut, USAF Major Michael Collins.

The Gemini 7 mission patch. (NASA)

 

A Change of Plans

In preparation for a December 1965 lift off, Gemini spacecraft number 7 was flown from McDonnell’s St. Louis facility and arrived at Cape Kennedy, Florida on October 5. The Titan II GLV-7 launch vehicle serial number 62-12562 was shipped from Martin’s Baltimore plant and arrived at the Cape on October 19. But before the hardware could be erected on the pad at Launch Complex 19, plans for Gemini 7 had changed. On October 25, Gemini 6 was supposed to lift off for its two-day mission to perform the first rendezvous and docking in space. Unfortunately, the Agena target vehicle for this mission never made it into orbit because of a failure of its primary propulsion system (see “The Unflown Mission of Gemini 6”). With no replacement target vehicle readily available, the original Gemini 6 mission plans were scrapped and a new plan quickly devised to keep the fast paced Gemini program on schedule.

Artist’s concept of the Gemini 6 and 7 rendezvous mission. (NASA)

The new plan called for Gemini 7 to be launched first on its original long duration flight from LC-19 on December 4, 1965. Ground crews would then quickly refurbish the pad and prepare what was now officially designated “Gemini 6A” for launch with the original crew of Walter Schirra and Thomas Stafford nine days later. Gemini 6A would then use Gemini 7 as a rendezvous target and perform a station keeping exercise. No docking would be attempted because of insufficient time to develop the needed hardware and procedures as well as address all of the safety concerns. In addition to supplemental training for Borman and Lovell who had already been practicing station keeping maneuvers with the Titan II, the only modifications required for Gemini 7 to support the new mission was the addition of an L-band radar transponder for Gemini 6A to track as well as target acquisition and orientation lights on the Gemini adapter section to improve visibility. The new plan was approved and publicly unveiled on October 28.

Since the Titan II GLV-6 already installed on the pad did not quite have the performance needed to launch the long-duration spacecraft number 7, which was almost 120 kilograms heavier than the one for the Gemini 6 rendezvous mission, spacecraft number 6 was destacked on October 28 and its Titan II removed from the pad at LC-19. The following day, GLV-7 was erected at LC-19. The modified spacecraft number 7 was finally mated to its launch vehicle on November 22. After a final simulated flight test on November 27, everything was ready for the launch of Gemini 7.

Lovell (left front) and Borman (right front) having their prelaunch breakfast with fellow astronauts. (NASA)

In order to keep Borman and Lovell in peak condition for their mission, it was decided not to disturb the crew’s preflight work and rest cycles so launch was scheduled for 2:30 PM EST. This allowed Borman and Lovell to sleep in until 7:00 AM on the December 4, 1965 launch day. During the course of the comparatively leisurely morning schedule which included the usual preflight medical examines, the crew had a traditional steak and eggs breakfast at 10:00 AM with some fellow astronauts. Included was a briefing from the backup crew, White and Collins, who had spent the morning working with the ground crews preparing Gemini 7 for launch.

Lovell and Borman exiting the suiting trailer wearing their G5C spacesuits on their way to LC-19. (NASA)

After breakfast, they were off to the trailer at LC-16 to don their new G5C spacesuits. Afterwards, Borman and Lovell were transported to LC-19 and got into their seats in the waiting Gemini. Following a nearly perfect countdown, Gemini 7 lifted off at 2:30:04 PM EST under clear skies and towards orbit for the longest crewed mission ever attempted. Almost immediately, ground crews began work to prepare LC-19 for the launch of Gemini 6.

The launch of Gemini 7 from LC-19 at 2:30:04 PM EST on December 4, 1965. (NASA)

 

First Days in Orbit

After the Titan II second stage had shutdown, the 3,663-kilogram Gemini 7 was in a 161 by 327-kilometer orbit with an inclination of 28.9°. Frank Borman fired Gemini’s aft OAMS thrusters for just two seconds to pull away from the spent second stage then turned the spacecraft around to start the station keeping exercise. In less than a minute, they had the spent rocket stage in view. Over the course of the next fifteen minutes, the astronauts took turns at the controls and were able to easily maneuver as they wished around the stage at distances of 18 to 46 meters thanks to the hours of practice in the simulator. The only complication was fuel venting from a broken line causing the Titan II second stage to tumble at about 2 RPM.

A view of the spent Titan II second stage during the Gemini 7 station keeping exercise immediately after reaching orbit. (NASA)

After Gemini 7 had performed a brief separation burn and had drifted away from its target, a 75-second OAMS thruster firing raised the low point of the spacecraft’s orbit to 222 kilometers ensuring that the orbit would not decay before the end of the nominal two-week mission. After a meal and some housekeeping chores, the astronauts settled down for their first night of sleep in orbit. Meanwhile back on Earth, work proceeded overnight at LC-19 where the post-launch assessment had revealed surprisingly little damage.

Lovell and Borman wearing their G5C spacesuits inside the Gemini 7 crew cabin. (NASA)

On the morning of December 5, ground crews began erecting Titan II GLV-6 back onto the pad at LC-19. As Borman and Lovell began their scheduled activities for their first full day in orbit, there were some minor glitches in orbit. The crew was having problems with the reticule of the photometer for the D-5 Star-Occultation Navigation experiment. Eventually the experiment was cancelled because of continuing issues with the hardware over the next few days. Frank Borman also accidentally pulled off an EEG electrode he was wearing for the M-8 Inflight Sleep Analysis experiment. The crew attempted to replace the electrode but were unsuccessful.

Frank Borman seen with an EEG electrode in place before his flight. This electrode was accidentally pulled off during the second day in orbit. (NASA)

On the third day, Jim Lovell was finally allowed by ground controllers to remove his G5C spacesuit. Lovell felt much more comfortable and was eventually given approval to sleep without his suit. Among the activities on this third day, the crew observed the launch of a Polaris A-3 SLBM (Submarine Launched Ballistic Missile) just off the coast from the Cape. The SLBM was fired by the “Gold Crew” of the nuclear-powered ballistic missile submarine, USS Benjamin Franklin (SSBN-640), as part of its shakedown cruise. That night, Lovell slept comfortably as Borman sweltered in his fully donned suit.

A photograph taken by the Gemini 7 crew during the launch of a Polaris A-3 SLBM off the coast of Cape Kennedy at 4:01 PM EST on December 6. The missile’s contrail is visible as a thin line in the upper right corner. Click on image to enlarge. (NASA)

On December 7, Borman fired the OAMS thrusters in the first of a series of maneuvers for the upcoming rendezvous with Gemini 6. This day’s trajectory adjustment placed Gemini 7 into a 188 by 302-kilometer orbit – the first step towards circularizing the orbit to approximate that of an Agena target vehicle. After much discussion, Lovell was allowed to sleep for another night with his suit off. As a concession to Borman, he was allowed to sleep with his gloves off and his hood fully opened to make his situation a bit more comfortable.

A view from Gemini 7 at 4:30 PM EST on December 8 looking across the Pacific Ocean towards the Moon above the horizon. (NASA)

As the Gemini 7 crew continued their marathon mission in orbit, Borman and Lovell had to contend with some minor spacecraft issues. On the sixth day there were indications of some issues in one of the fuel cell stacks. Since the power produced by the fuel cells was vital to the long duration mission, crew and ground controllers continued to monitor their performance. On the morning of the seventh day the crew woke up to find Gemini 7 tumbling at a rate of 10 degrees per second probably as the result of exhaust from a water boiler used for cooling the spacecraft systems. The affected radiator was manually bypassed and OAMS thrusters were employed to steady the craft.

Fuel cells like these were the only way to power long duration mission such as Gemini 7 and the Apollo lunar missions. (NASA)

By December 9 it was apparent that preparations for the launch of Gemini 6A were proceeding ahead of schedule and that launch could take place a day early on December 12. In preparation for this launch, Borman fired Gemini’s thrusters for 78 seconds to raise its perigee to 299 kilometers. A second burn a half orbit later lowered the apogee to 303 kilometers. Gemini 7 was now in its “circular” orbit to wait for the arrival of Gemini 6.

A view of the Mission Control Center in Houston, Texas during the Gemini 7 flight. (NASA)

By the next day, the temperature inside the Gemini 7 crew cabin had risen to an uncomfortable 29.4° C and once again the issue of spacesuits was raised. Because of various delays, Borman had remained in his spacesuit since launch while Lovell had spent the previous four days in the relative comfort of his undergarments. Finally after Borman’s multiple requests, the crew was instructed late in the afternoon to switch suit modes – Lovell had to put his suit back on while Borman was finally allowed to remove his. Borman would finally have a chance to cool off and get a comfortable night’s sleep. The next day, the long duration crew performed more experiments and made preparations for the launch and rendezvous of Gemini 6.

 

The Long Grind

On the morning of December 12, preparations proceeded on schedule for the launch of Gemini 6. As Gemini 7 passed over Cape Kennedy at 9:54 AM EST as Gemini 6 was supposed to launch, Borman and Lovell could see the plume from the ignition of the Titan II first stage engines that were intended to send Gemini 6 on its way to an orbital rendezvous. But based on their own experience and having witnessed the launch of a Polaris A-3 SLBM from orbit just six days earlier, they could tell that the launch had been aborted – an observation confirmed by Mission Control. With the long awaited rendezvous postponed, the Gemini 7 crew continued their marathon mission in orbit (see “Rendezvous in Space: The Gemini 6 Launch Abort”).

This image, acquired at 9:53 AM EST on December 12, shows Cape Kennedy as seen from Gemini 7 at the time of the Gemini 6 launch abort. (NASA)

At 1:25:18 PM EST, as engineers and technicians on the ground were still assessing the cause of the Gemini 6 launch abort, Borman and Lovell surpassed the 190 hour, 55 minute, 14 second space duration record set just 3½ months earlier by the crew of Gemini 5 (see “Eight Days or Bust: The Mission of Gemini 5”). Although December 12 was going smoothly for them in orbit, the strain of the long duration mission was taking a toll on the Gemini 7 crew especially after the launch abort. Neither astronaut was in the best of spirits with Borman observing “Jim and I are beginning to notice the days seem to be lengthening a bit.” With the uncomfortable cabin temperature, lack of adequate toilet or cleaning facilities and the tight confines of the Gemini crew cabin, Borman added “We’re getting a little crummy up here.”

Frank Borman shown on board Gemini 7 with the hood of his G5C suit open. (NASA)

The psychological impact of the long duration mission was especially noticeable on Borman who was the mission commander. While for the first few nights of the mission Borman was averaging about six hours of sleep like Lovell, by the end of the first week in orbit, he was typically only sleeping 4½ to 5 hours a night despite being allowed to remove his G5C spacesuit for the first time during the sixth day of the mission. Keenly aware of his responsibilities, Borman slept fitfully and woke frequently to scan the spacecraft’s instruments before drifting back to sleep.

The day after the launch abort, it became clear that Gemini 6 could not only attempt another launch but that the ground crews could shave a day off of the normal four-day turn around. Another launch attempt would be made on the morning of December 15. Meanwhile in orbit, Borman and Lovell had to contend with another fuel cell issue. A warning light indicated that excess water was building up in the waste tank. This was flushed out by forcing extra oxygen through the system from the crew compartment’s reserve supply. On December 14, the crew continued with their experiments in orbit. This included observing the reentry of an ICBM reentry vehicle over the Eniwetok Atoll in the Pacific Ocean after it had been launched from Vandenberg Air Force Base in California by a Minuteman ICBM – the first such observation from space.

A view of the launch of Gemini 6 from LC-19 at Cape Kennedy on December 15, 1965. (NASA)

Gemini 6 finally lifted off the pad at LC-19 on schedule at 8:37:27 AM EST on December 15 but out of view of Gemini 7 overhead due to clouds along their line of sight. The spacecraft with Wally Schirra and Tom Stafford on board accelerated until the first stage finally burned out 156 seconds after launch. Stafford checked the guidance computer at that moment and got a velocity reading of 7,830 meters per second indicating that they were well on their way after a false start three days earlier. A brief flash engulfed the ascending spacecraft as the second stage ignited. After five minutes and 41 seconds of powered flight, Gemini 6 was finally in a 161 by 259-kilometer orbit some 1,992 kilometers behind Gemini 7. A few minutes later, Borman and Lovell finally observed the contrail from Gemini 6 and even caught a brief glimpse of the spacecraft itself as they passed over Africa. The Gemini 7 crew donned their G5C lightweight spacesuits and waited for company to arrive.

 

The Rendezvous

With Gemini 6 finally in orbit, the US had started its first two-spacecraft crewed mission. The Soviet Union had already flown dual space missions before with their one-person Vostok spacecraft: Vostok 3 and 4 in August 1962 followed by Vostok 5 and 6 in June 1963. But the relatively primitive Vostok was incapable of performing an actual rendezvous and these spacecraft simply passed within about five kilometers of each other just because of good aiming at launch. Gemini 6 and 7 were real “spaceships” in the sense that they could maneuver from one orbit to another using computer processed radar information to bring them together in orbit.

A number of different rendezvous modes with an orbiting target had been identified during theoretical studies of the issue. The most aggressive and fastest of these, which would be preferred for the Apollo missions when the Lunar Module departed the Moon’s surface, was the “first apogee” method where the active spacecraft would be launched directly into an elliptical orbit that would allow a rendezvous with the passive target spacecraft during the active spacecraft’s first apogee. This method required a fast-paced sequence of precisely timed and executed maneuvers in order to be successful. For the Gemini 6 mission, the “coelliptical” method was chosen instead where the active spacecraft would first be placed into a circular orbit below and some distance behind the passive target spacecraft (Gemini 7, in this case) which is in its own circular orbit. The active spacecraft would then catch up to its target over the course of several revolutions then maneuver to match the target’s orbit in order to perform the actual docking. While this approach took longer, it was much more flexible and allowed more time to plan and execute maneuvers – a desirable characteristic for the first attempt of the untried orbital rendezvous procedure. For this mission. Gemini 6 would attempt what was called an “M=4” profile where the rendezvous would take place during the 4th revolution.

A schematic showing the rendezvous orbit geometry intended for the Gemini 6 mission. Units on this diagram are in nautical miles (1 nm = 1.852 km). Click on image to enlarge. (NASA)

Being in a lower orbit with a shorter period, Gemini 6 was able to close in on Gemini 7 very quickly. About 94 minutes after launch with Gemini 6 trailing Gemini 7 now by 1,175 kilometers, Schirra used the OAMS (Orbital and Attitude Maneuvering System) thrusters on Gemini 6 to increase its velocity by 4 meters per second raising its apogee up to 272 kilometers. After two hours and 18 minutes of flight, Schirra added 19 meters per second to the chasing craft’s velocity to begin the phase adjustment to reduce the distance further and raise the perigee to 224 kilometers. A half an hour later over the Pacific, another OAMS burn maneuvered Gemini 6 into the same orbital plane as Gemini 7 which was now only 483 kilometers away.

After three hours and 15 minutes, Gemini 6 activated its L-band radar to attempt to detect the transponder carried by Gemini 7 and established a lock at a range of 434 kilometers. At mission elapsed time of three hours 47 minutes, the aft OAMS thrusters of Gemini 6 were fired for 54 seconds to increase the velocity by 13 meters per second. This placed Gemini 6 into a nearly circular 270 by 274-kilometer “final intermediate orbit” to slowly catch up to Gemini 7 now only 319 kilometers away. Four minutes later, Schirra and Stafford entered an automatic rendezvous mode under the control of their onboard computer.

After five hours and four minutes of flight, Schirra spotted Gemini 7 just 100 kilometers away as a bright star. Twelve minutes later, Schirra began the final series of maneuvers to bring the two spacecraft close to each other. During the terminal stage of the rendezvous, Schirra and Stafford both saw Gemini 7 aligned with the stars Castor and Pollux in the constellation of Gemini as they completed their last nighttime pass before finishing the rendezvous. Gemini 7 blazed into view as it passed into sunlight 200 meters ahead of Gemini 6 at orbital dawn. After a series of small braking maneuvers, Gemini 6 finally stopped 40 meters from Gemini 7 completing the first rendezvous in the history of spaceflight at 2:33 PM – just under six hours into the mission of Gemini 6. Cheers erupted at Mission Control as flight controllers waved American flags and celebratory cigars were lit.

A view of Gemini 7 during station keeping with Gemini 6. (NASA)

High above the Pacific Ocean, the four astronauts happily exchanged greetings and jokes. “You guys sure have beards” quipped Schirra as he saw the smiling faces of Borman and Lovell through the windows of their Gemini 7 spacecraft. At one point, Stafford (who was a graduate of the US Naval Academy like Schirra and Lovell) placed a “Beat Army” sign in his window as a friendly dig at West Point alumnus, Borman, in reference to the traditional Army-Navy football game (which had ended in a 7-7 tie 2½ weeks earlier).

A view of Gemini 6 where Stafford has displayed a “Beat Army” sign in his window. (NASA)

For the next three orbits, all four astronauts took turns controlling their respective spacecraft during station keeping exercises as they drifted as far apart as 90 meters and maneuvered in as close as just 0.3 meters. The crews performed a series of tests and determined that they had no problems maneuvering their spacecraft accurately with respect to each other or visually tracking each other even during the night time passes. According to the final tally, the rendezvous of Gemini 6 had used only 51 kilograms of propellant with 62% still unused in the spacecraft’s tanks. With the successful conclusion of this exercise, NASA was now ready to attempt a docking during the upcoming Gemini 8 mission (see “Gemini 8: The First Docking in Space“) the two spacecraft a safe distance of 16 kilometers apart. Both crews ate a good meal and went to sleep to get some well deserved rest as a pleasing observation “we have company tonight” came in from Gemini 7.

 

Coming Home

The morning of December 16, Schirra woke up with a stuffy head and a runny nose. Fortunately, the Gemini 6A mission had met all of its primary objectives and was ready to return to Earth after only a day in orbit freeing up tracking and recovery resources for the last three days of the Gemini 7 mission. But before Gemini 6 left orbit, Tom Stafford radioed in “This is Gemini Six. We have an object, looks like a satellite, going from north to south, up in a polar orbit. He’s in a very low trajectory… looks like he may be going to re-enter pretty soon. Stand by… it looks like he’s trying to signal us.” A few seconds later this was followed by a rendition of “Jingle Bells” from a small, four-hole Hohner harmonica Schirra had carried with him and the tinkling of little bells by Stafford – Christmas was only nine days away and the crews were going to start heading home.

A view of Gemini 7 in orbit with Frank Borman and Jim Lovell on board for a record-long mission. (NASA)

With a final call to Gemini 7 from Schirra, “Really good job, Frank and Jim. We’ll see you on the beach.” Schirra then flipped Gemini 6 blunt-end forward and fired the retrorockets on schedule for the return to Earth in the primary recovery zone in the west Atlantic Ocean. The final objective of the mission was to perform a precision reentry and landing. Schirra initially placed the descending reentry module in a heads-down attitude then banked to 55° left at an altitude of 100 kilometers. The onboard computer took control of the descent at 85 kilometers banking the module one way then the other to keep on course.

At an altitude of 24 kilometers, the Gemini 6 reentry module was coming straight down with the parachute deployment starting at 14 kilometers and the main chute out at 3,200 meters. Gemini 6 splashed down just 12.9 kilometers from the planned aim point at 10:28:50 AM EST after a mission of 25 hours, 51 minutes and 24 seconds. While Navy frogmen were in the water and attached a flotation collar on the reentry module, Schirra and Stafford opened the hatches and opted to be picked up by the recovery carrier, the USS Wasp, 62 minutes after landing. In another first, the whole operation was broadcast live back to television viewers in the US from the USS Wasp via satellite. After so many false starts, the Gemini 6 mission was successfully concluded.

Stafford and Schirra shown in the Gemini 6 reentry module after splashdown on December 16, 1965. (NASA)

Meanwhile in orbit, the departure of Gemini 6 was a real let down for Borman and Lovell who still had two days left before their return to Earth. They continued to deal with fuel cell issues as well as other minor system malfunctions and were growing less tolerant of each other. At 9:30 AM on December 16 as Gemini 6 was preparing to leave orbit, a problem was noted in two of the thrusters on Gemini 7 used for yaw control. With the station keeping exercise completed and with only three days left, it was decided that backup systems and operating in a free drift mode would suffice for the remainder of the mission. But there was also some good news for the weary astronauts: After consultation with doctors and engineers, it was decided that the Gemini 7 crew would be much more comfortable out of their G5C spacesuits and that the benefits far outweighed the risks. For the first time in the mission, both astronauts were allowed to remove their spacesuits at the same time and leave them off until their return from orbit.

Here is an image of clouds over the upper Amazon Basin as seen from Gemini 7 at 1:43 PM EST on December 17 – the last full day of the mission. (NASA)

On December 17, Borman and Lovell were given the final go to complete their 14-day mission despite ongoing fuel cell issues. Analysis by NASA and McDonnell engineers indicated that they would perform adequately for the remainder of the mission. With the relief of this good news, Borman slept better than he had before during the mission. Learning from the experiences of the Gemini 5 long-duration crew, the Gemini 7 crew brought along a couple of books to help pass the time and relax during periods of drifting flight over the last couple of days in orbit. Borman read some of Mark Twain’s Roughing It recalling the author’s adventures in the American West during the 1860s. Lovell brought part of Drums Along the Mohawk by Walter D. Edmonds. Both books were chosen, in part, because they had nothing to do with spaceflight.

After stowing all of their gear and two-week’s worth of trash not to mention getting back into their rather soiled G5C spacesuits for one last time, Frank Borman and Jim Lovell were ecstatic about finally coming home on December 18. With only 24 hours of oxygen, 10 hours of power and almost no water left, the retrorockets on Gemini 7 fired automatically in sequence to begin the return to the west Atlantic recovery zone where the USS Wasp was waiting. Like Gemini 6, the last objective of Gemini 7 was to perform a precision landing. Borman banked the reentry module at 35° due to a ground controller error instead of the planned 53°. By the time the error was noticed, the computer was already online and commanding the reentry maneuvers. Borman had a wager with Schirra about who would come down closest to their aim point during their precision landing and this was not a good start. Guided by the computer, the Gemini 7 crew experienced braking loads of 3.9 Gs which “felt like a ton” after a fortnight in weightlessness.

Lovell and Borman in a raft shortly after splashdown waiting to be picked up. (NASA)

Gemini 7 came through its reentry and made its splashdown at 9:05:05 EST after a flight lasting 330 hours, 35 minutes and 1 second – just 5½ hours short of two weeks and a space endurance record that would stand until the 18-day Soyuz 9 mission in 1970. And despite the initial navigation error, Gemini 7 came down only 11.8 kilometers off target and 1.1 kilometers closer than Schirra in Gemini 6. Although Borman felt a little dizzy at first, Lovell felt fine. And while the astronauts had initially planned on taking off their spacesuits immediately after landing, they decided it was not worth the effort and opted to leave them on until they were recovered.

Lovell and Borman shown after their arrival on the deck of the USS Wasp at the end of their record-long space mission on Gemini 7. (NASA)

As before, Navy frogmen were in the water to secure the Gemini reentry module shortly after splashdown. Borman and Lovell, who opted for a helicopter recovery, were on the deck of the USS Wasp only 32 minutes after landing followed a half hour later by their spacecraft. Aside from a general sense of fatigue, the Gemini 7 crew survived their long-duration mission and were soon back to their preflight condition. With the successful conclusion of this two-week flight (which was longer than any planned for the Apollo lunar missions) and the first rendezvous in space, NASA was one step closer to the Moon. In fact, just three years after the Gemini 7 mission, Borman and Lovell would be reunited to fly the Apollo 8 mission with rookie astronaut Bill Anders for the first crewed mission to orbit the Moon (see “Apollo 8: Where No One Has Gone Before“).

Gemini 6 and 7 reentry modules shown together on the USS Wasp after their recoveries. (NASA)

 

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Related Video

Here is an excellent NASA documentary on the Gemini 6 and 7 mission from 1966 entitled “Proud Conquest: Gemini VII and VI”.

 

 

Related Reading

“Rendezvous in Space: The Gemini 6 Launch Abort”, Drew Ex Machina, December 12, 2015 [Post]

“Rendezvous in Space: The Launch of Gemini 7”, Drew Ex Machina, December 4, 2015 [Post]

“The Unflown Mission of Gemini 6”, Drew Ex Machina, October 25, 2015 [Post]

 

General References

David Baker, The History of Manned Space Flight, Crown Publishers, 1981

Barton C. Hacker and James M. Grimwood, On the Shoulders of Titans: A History of Project Gemini, SP-4203, NASA History Division, 1977

David J. Shayler, Gemini: Steps to the Moon, Springer-Praxis, 2001

“Gemini 7/6”, NASA Press Release 65-362, November 29, 1965