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.
Official NASA Account of the Mission from On the Shoulders of Titans: A History of Project Gemini, by Barton C. Hacker and Charles C. Alexander, Published as NASA Special Publication-4203 in the NASA History Series, 1977.
After a smooth countdown, Atlas launch vehicle 5303 rose from pad 14 at 10:12 a.m. For two minutes the rocket's three engines rammed Agena 5004 skyward. Only ten seconds before the two outboard engines were supposed to stop, however, one of them gimbaled and locked in a hardover pitchdown position. The whole combination - Atlas and Agena - flipped over into a nosedive and headed like a runaway torpedo back toward Cape Kennedy.
Shortly after the booster engines stopped firing, the guidance control officer reported he had lost touch with the launch vehicle. Richard W. Keehn, General Dynamics program manager for the Gemini Atlas, was alarmed and puzzled. Telemetry showed that the sustainer engine had cut off, and a signal that the Agena had separated from its launch vehicle followed. Agena signals kept coming until 456 seconds after launch - then there was silence. Keehn raced over to Hangar J, the General Dynamics data station, where the telemetry tapes pointed to an Atlas engine problem. But television reports implied that the target vehicle was in trouble again, and Lockheed officials winced whenever they heard someone speak of the "Agena bird"; this was ironic in the light of the problems and delays caused by Atlas in the Mercury program and the success of Agena in Project Surefire and Gemini VIII. Meanwhile, the Gemini IX Atlas and Agena had plunged into the Atlantic Ocean 198 kilometers from where they had started.
As contractors worried about technical problems, NASA again faced the necessity for a quick recovery plan when a target vehicle failed to reach orbit. This time, however, the agency had something in the hangar, an alternate vehicle - the ATDA. After the Agena exploded in October 1965, NASA had ordered General Dynamics/Convair to be prepared to furnish a backup Atlas within 14 days of another such catastrophe. And in April 1966, just a month before the attempted launch of Gemini IX, Schneider had reminded Preston that he would have to be ready to launch the alternate target in a hurry if the Agena again failed to keep its orbital appointment. Now it had. On 18 May, Mathews wired Colonel John Hudson, Deputy Commander for Launch Vehicles, Air Force Space Systems Division, to prepare Atlas 5304 for launch on 31 May in a mission now called Gemini IX-A.
With what had been the backup plan now in effect, the next question was what to do if the ATDA, too, failed. At a staff meeting on 18 May, Mathews announced that Gemini IX-A would be launched anyway, to rendezvous with the Gemini VIII Agena, still in orbit. McDonnell, in any case, was confident of the ATDA. When Mathews asked, in a management meeting in St. Louis the next day, "Does anyone have any reservations about flying the ATDA?" the answer was no. That was just as well, because the motion of a rendezvous with the old Agena soon had to be abandoned. Its orbit had not decayed to the expected extent, and it was still sailing around Earth 402 kilometers up. Without the help of Agena, high- altitude flight might take too much spacecraft fuel and leave the crew stranded with no way to get to the lower orbit needed for retrofire. Deputy Administrator Robert Seamans and Mueller agreed with Mathews that rendezvous with Agena 8 was too risky, but Gemini IX-A would still fly, even if the substitute target did not make it. Extravehicular activity with the AMU was a much needed venture in its own right.
Long before these decisions were made, the Atlas contractors were frantically busy. Keehn had bundled up the telemetry tapes and headed for San Diego, where study of the data plus some tests located the trouble in the electrical wiring. Within a week, Keehn and his group pinpointed the cause of the failure: a pinched wire in the autopilot that produced a short circuit. This meant some extra work on the electrical connectors, and General Dynamics asked NASA for an extra day to complete the task and prepare Atlas 5304 for launch. The agency set 1 June as the new date.
Although General Dynamics had accepted the blame for the mission failure, Lockheed was worried about telemetry signals that indicated a problem with an Agena inverter. A nagging question persisted. Could the target vehicle have gone into orbit if the Atlas had worked? This inverter provided power to both the gyroscope and the sequence timer. To Lockheed's relief, a series of row cameras located at Melbourne Beach, Florida, got pictures of the Atlas' outside loop. They showed that the Agena passed through ionized gases from the booster's exhaust, which caused an electrical short and failure of the inverter.
On 1 June 1966, men and machines were again gathered at the Cape Kennedy launch site, this time to try to send the alternate target vehicle and Gemini IX-A into coordinated orbital flight. At the appointed time, 10:00 a.m., the Atlas rose from pad 14. After a six-minute boosted phase, it tossed the ATDA into a nearly perfect 298-kilometer orbit. Just one thing marred the picture: telemetry signals suggested that the launch shroud covering the docking port had only partially opened and had failed to jettison.
Concurrently, over on pad 19, Stafford and Cernan were going through their countdown to launch. When the count reached the three-minute mark, a hold was called so the spacecraft could be launched precisely on time for the best catchup trajectory with its target. Almost immediately after the count resumed, problems developed in the Cape ground launch control equipment when it tried to send the spacecraft refined information on the exact launch azimuth. The launch window (only 40 seconds long) closed, and Mission Director Schneider delayed the flight for 48 hours. For the second time, Stafford and Cernan had to take the elevator down. Stafford later said, "Frank (Borman) and Jim (Lovell) may have more flight time, but nobody had more pad time in Gemini than I did!" By the time Gemini IX-A lifted off, he had been in the two spacecraft (6 and 9) ready for launch a total of six times.
Stafford and Cernan met with no untoward incidents on 3 June. The flight began precisely at 8:39:50 a.m. Stafford watched the instruments more closely than had his predecessors, since he had this new IVAR (insertion error correction) to handle in starting the rendezvous sequence. Six minutes after launch, CapCom Neil Armstrong said, "You are go for IVAR." Seconds later, the command pilot fired the spacecraft thrusters in the chase toward the target vehicle 1,060 kilometers ahead.
By the time Stafford and Cernan arrived over the Canary Islands - only 17 minutes after launch - the computers had ground out the figures. Armstrong gave the crew the data for the phase adjustment near the first apogee. At 49 minutes into the flight, the thrusters added 22.7 meters per second to spacecraft speed to raise its perigee from 160 to 232 kilometers. "I felt that one. Tom!" Cernan exclaimed.
During the hour before the triple play - to correct phase, height, and out-of-plane errors - the crew checked systems, went through stowage lists, took off gloves and helmets, and got cameras ready for the rendezvous. To circularize the flight path, at 2:24 hours elapsed flight time Stafford pitched the nose of the spacecraft down 40 degrees and turned it three degrees to the left of its flight path. Fifty-one seconds later, he fired the aft thrusters to add 16.2 meters per second to the vehicle's speed. The orbit now measured 274 by 276 kilometers - 22 kilometers below and 201 kilometers behind the target vehicle and closing with it at 38 meters per second.
Over Tananarive, 12 minutes before Stafford had fired the thrusters, the crew got some flickers of a radar contact with their target. A range reading of 240 kilometers between the vehicles showed on the scale. George Towner and the other Westinghouse radar builders were relieved; they had worried about acquisition of a target that would wig, wag, and wobble. The Agena was a stabilized vehicle; the ATDA was not, and its radar reflectivity changed with its continually changing attitude. Within 222 kilometers, however, electronic lockon was relatively good.
At 3:20 hours, the crew caught sight of their goal 93 kilometers away. For some time, it flitted in and out of view on an optical sight. At 56 kilometers, it became quite clear and remained visible from then on. As he drew nearer, Stafford reported seeing flashing acquisition lights. Thinking for a moment that the shroud had jettisoned after all, he said, "All right. We're in business." Surely they could not have seen the running lights so clearly if the shroud were still attached. While making minor corrections, he was glad that he could see the little "shiners" so well, because moonlight, streaming through his window, almost blinded him. The Moon soon became an asset, however, as its rays reflected off the ATDA.
Stafford began slowing his spacecraft at 4:06 hours. During the closure period, he peered out the window, trying to see if the shroud was there or not. Then he exclaimed, "Look at that moose!" As the distance dwindled, he knew that he had been indulging in wishful thinking - "The shroud is half open on that thing!" Seconds later, Cernan remarked, "You could almost knock it off!" When the final braking was completed,the two vehicles were only 30 meters apart and in position for stationkeeping. But it did not seem likely that the spacecraft nose could slip into the mouth of the "moose" and dock.
The crew described the shroud in detail and wondered out loud what could be done to salvage the situation. One of Stafford's remarks - graphic and memorable - became the trademark of the entire mission. His animal analogy switched to reptilian when he said, "It looks like an angry alligator out here rotating around." He itched to nudge it with his spacecraft docking bar to open its yawning jaws, but Flight Director Kranz told him to control the urge.
Perhaps the most significant aspect of this incident was the close examination of an unstable body while discussing it over the air-to-ground circuit. Stafford stayed 9 to 12 meters from the target but moved to a ticklish position only centimeters away in daylight. As the ATDA rotated slowly, he rolled his spacecraft upside down to parallel the movements of this weird looking machine. His performance met, in effect, one of the Defense Department's objectives for the AMU - finding and inspecting unidentified satellites. Stafford said he could plainly see that the explosive bolts had fired but that two neatly taped lanyards held the clam shell partially in place. These lanyard wires had high tensile strength, he was assured from the ground, so it might not be wise to nudge its jaws.
Schneider called James McDivitt and Scott, who were in Los Angeles, and asked them to go to the Douglas plant and look at a duplicate target vehicle shroud to see if the wires could be cut or the shroud removed in any way during orbital flight. The astronauts soon reported that the wires could be clipped, but there were many sharp edges that might tear the astronaut's suit as he worked. In the meantime, ground controllers sent signals to the target to tighten and relax the docking cone, hoping that might free the shroud. But it remained in place - there would definitely be no docking on Gemini IX-A.
The shroud episode was embarrassing, and another investigation began immediately. The solution was simple, if one recalls the old saw about too many cooks spoiling the broth. Douglas built the shroud that Lockheed, in turn, fitted to the Agena. The ATDA, however, was built by McDonnell. Before McDonnell technicians made the final installation on the ATDA at the Cape, a Douglas engineer supervised a practice run, with the exception of the final part - the lanyards that operated the electrical disconnect to the explosive bolts. For safety's sake, these were not hooked up. Before the mission, the Douglas engineer went home to his pregnant wife. On launch day, the McDonnell crew followed procedures published by Lockheed, which had been copied from Douglas documents. The instructions said, "See blueprint," but the Lockheed drawing was not used. The Douglas technician who normally hooked up the lanyards knew what to do with the loose ends, even without the blueprint. But he was not there, and the strangers fixing the ATDA's shroud looked at the dangling straps, wondered what to do with them, then taped them carefully down. In orbit, Stafford photographed their neat handiwork.
As Scott Simpkinson, GPO Manager of Test Operations, later said, three good lessons were learned from this mistake: (1) simulate processes completely, (2) keep experienced people on the job, and (3) follow written procedures exactly.
Gemini IX-A now began its equiperiod rendezvous. Five hours after launch, Stafford nosed the spacecraft down 90 degrees and fired the forward thrusters for 35 seconds to increase his speed by 6 meters per second. The crew quickly found that the target was disappearing below them. Later, in the darkness, they plotted their position with a sextant and checked the result against a preplanned chart solution. Mission planning had been right; all that was necessary to complete the rendezvous was to slow the spacecraft down. At 6:15 hours, Stafford began a series of four maneuvers to bring the spacecraft back to stationkeeping alongside the target. The second of the three rendezvous exercises was easy.
Less than an hour after Gemini IX-A returned to its target (6:36 hours elapsed time), the crew got ready to leave again, for the third planned rendezvous. At 7:15 hours, Stafford fired the aft thrusters to decrease the spacecraft speed by 1.1 meters per second and widen the distance between the two satellites.
Stafford and Cernan could now relax a little. It had been an exhausting day. Still wanting to snap the alligator's jaws off, they chatted with ground controllers about the shroud. Then they checked spacecraft systems, ate, and tried to sleep. Cabin noises and lights made sleeping difficult, however, and they only dozed for 40 minutes or so at a time; their scheduled eight hours of slumber were fitful, at best.
The next day - 4 June - Spacecraft 9 led its target by 111 kilometers. That retrograde maneuver (against the direction of the flight path) had lowered the orbit of the spacecraft (it now measured 289 by 296 kilometers) and the target traveled a nearly constant 298 kilometers above the planet. Thus the spacecraft, being nearer Earth, illustrated the paradox of slowing down to go faster, relative to the surface of the world, than the object flying overhead. The stage was set for Stafford and Cernan to do a rendezvous from above; but they first had to accelerate the spacecraft in the direction of the flight path so it would leap to a higher altitude than the target. Automatically, then, the lower flying target would reduce the spacecraft's 110-kilometer lead. To rendezvous, the crew only had to cancel out altitude and velocity vectors that had placed their vehicle above and ahead of its objective.
A phase adjustment at 18:23 hours was followed a little more than 30 minutes later by a height adjustment. Another burst from the thrusters put the spacecraft into an orbit measuring 307 by 309 kilometers. The slant range to the target, which had stretched to 155 kilometers, began to shorten. Within 15 minutes, Stafford reported that the vehicles were only 100 kilometers apart. Forty minutes later, Cernan called out a 37- kilometer mark. At 21:02, the distance was 28.6 kilometers. Stafford pointed the nose of his spacecraft down 19 degrees and yawed it to the left 180 degrees, aiming at the other vehicle, which was still below and behind him.
Over the Atlantic Ocean, then the Sahara Desert, on past the African continent, Stafford and Cernan had troubled spotting the target, but the electronic eye of the radar did not. When they were 37 kilometers away, they had seen the vehicle reflected brightly in the moonlight and, later, in the sunlight. As the Sun rose, however, they lost sight of it completely. The range had closed to less than six kilometers before Stafford saw what looked to him "like a pencil dot on a sheet paper." Without the radar, he said, they would "have blown that rendezvous." But at 21 hours and 42 minutes after launch, IX-A and the target were again side by side. Three types of rendezvous had been completed in less than 24 hours.
At the end of the third rendezvous, the Carnarvon, Australia, flight controller told Cernan that Flight Director Charlesworth wanted the crew to start getting ready for EVA. Stafford had begun to worry about the amount of fuel that would be consumed if he continued stationkeeping with the target. Unless the flight controllers thought Cernan might actually do something about the shroud, the command pilot wanted to get out of the vicinity of the ATDA before the pilot got out of the spacecraft. The crew was also pretty tired. As they approached Houston, Armstrong told Stafford to postpone EVA until the third day and to leave the ATDA. Stafford accelerated the spacecraft by one meter per second and moved away forever from the angry alligator.
On 5 June, at 5:30 a.m., nearly 45 hours and 30 minutes into the mission, the crew began preparations for Cernan to emerge from the spacecraft. In the cramped cabin, they worked, rested, and worked again, finishing ten minutes before sunset. Near sunrise, Cernan cracked his hatch. It took more effort than he expected, but he soon stood in the opening, looking out at infinity and waiting for the first signs of daylight. Cernan had no feeling of disorientation nor any sensation of being lost in the dark of space. He heaved out a litter bag, the start of an exercise scheduled to last 167 minutes, during which the pilot would stand, walk, float, or ride nearly twice around the world.
Once outside the spacecraft, Cernan did some simple experiments to get the feeling of working in space. He was startled to find that everything took longer than he had assumed it would from his experience in simulations. Cernan said he really had no idea how to work in slow motion at orbital speeds. Every movement of an arm or leg in free space exacted a reaction from his body.Minute forces that would scarcely be noticed in Earth's gravity upset his equilibrium in space. He had only to twitch his fingers to set his body in motion. On Gemini IV, White had commented on the need for handholds. Now Cernan found that even those installed on Spacecraft 9 were inadequate and that the Velcro was not strong enough to keep his body in position as he edged back toward the adapter. He had to fight the limited mobility of his space suit, and the effort taxed his strength. He constantly referred to the umbilical as the "snake." When he let it out to any distance, it was hard to control.
When he finally reached the adapter, some lights that had been installed especially to help him see were not burning. He asked Stafford to turn them on, but only one lit up. Moving around the adapter was no easier than moving around the rest of the spacecraft. Still, he began preparing the maneuvering unit for flight. He attached penlights; opened and checked the nitrogen and oxygen shutoff valves; positioned the sidearm controllers, umbilicals, and restraint harness; attached the AMU tether; turned on the unit's electrical power; and changed over to the electrical umbilical. Everything, just everything, took much longer than he had expected. He kept floating out of control; he simply could not maintain body position. The few footbars, stirrups, and handbars were insufficient for any task that required leverage.
Ten minutes after sunset, Cernan's faceplate began to fog, so he rested. But here there could be no such thing as complete relaxation because of the tendency to drift away. He went back to work, but his visor soon fogged again. After the next sunrise, the moisture lessened. As soon as he moved about, it returned. Strangely, he felt neither hot nor cold - his only problems were this fogged visor and tasks that had to be done with one hand when he really needed two.
When 80 percent of his work was finished, Cernan again had to stop and rest. Like a mountain climber with a backpack, he sat down in the maneuvering unit and found his most peaceful moment in this strange environment. Body molded to the seat, feet against a footbar, and arms atop the handbars, he enjoyed a taste of comfort for the first time since he started this stroll outside. The flight passed into darkness, but by the light in the adapter Cernan could tell just how occluded his faceplate had become.
He began to wonder whether to go on with EVA. Mentally, he ticked off the checklist items that remained: strap in, change to the AMU oxygen lead, start breathing oxygen from the unit's supply, and free his personal transportation from the spacecraft adapter. Cernan knew, from repeated experience in zero-g training flights, that he could do these tasks blindfolded. But then what? he thought. "So you make the connections . . . if you can't see, you can't very well go out there and fly because you don't know what to expect." And if he flew the maneuvering unit, anyway? He could finish putting it on, he knew, because he was restrained in the adapter. But when the time came to take it off, he would be standing in free space. Could he take it off with one hand, while holding onto the spacecraft with the other? Would it be wise to try that when he couldn't see? Much better to end the exercise now, he thought. So he and Stafford decided to cancel the rest of the EVA,and Mission Control agreed.
Carefully, Cernan eased himself out of his comfortable seat, leaving his sun visor up to see if that might help defog his faceplate. At sunrise, he detached the AMU's electrical umbilical and connected his spacecraft lifeline. Still almost blind, he groped his way out of the adapter and back along the spacecraft to the cockpit. He slid into the hatch and stood there a few moments. Stafford held on to Cernan's legs so he could rest. Slowly his faceplate began to clear in the center, giving him a narrow range of vision. He tried to retrieve an externally mounted mirror that the command pilot had used to watch what was going on behind the cockpit. As Cernan wrestled with the mirror, his suit's cooling system became overtaxed, causing him to get extremely hot for the first time. His faceplate again fogged up completely. Stafford helped Cernan in and, together, they closed the hatch and started pressurizing the cabin. With their helmets almost touching, Stafford still could not see Cernan through the faceplate. The extravehicular exercise had lasted for 128 minutes instead of the planned 167; fogging had started 63 minutes after hatch opening.
Two major aims of Gemini XI-A were rendezvous and extravehicular activity; the third was experiments. Stafford and Cernan gave closer attention over a sustained period of time to the assigned experiments than had any Gemini crew before. When the space walk was postponed to the third day, the astronauts spent most of the second day on experiments and rest. About the only conversation they would tolerate from the ground was about their workload. On several occasions, when flight controllers forgot, they were reminded that the crew was busy. "My mistake for contacting you," came the response.
Stafford and Cernan carried out M-5, bioassay of body fluids (the only medical experiment), which required wastes to be collected and labeled in laboratory fashion. Like other Gemini crews, Stafford and Cernan disliked this complex and messy task, nor did they enjoy the blood sampling they had to endure before and after the mission. Stafford equated the physical effort for M-5 to that required for doing a rendezvous and a half.
The Department of Defense sponsored one experiment in addition to the Astronaut Maneuvering Unit - D-14, UHF/VHF polarization - to measure the inconsistencies of the electron field along the spacecraft orbital path and to study structures and variations of the lower ionospheric region. Stafford and Cernan operated the D-14 transmitter five times over Hawaii and once over Antigua during five successive revolutions. Everything worked well, but the number of measurements was limited because the antenna was poorly located. Later, when he was struggling outside, Cernan accidentally broke off the D-14 antenna.
The four remaining experiments were scientific. Two of these involved micrometeorite collection. S-10 was a package mounted on the ATDA for Cernan to pick off during his space walk. This he could not do, but the astronauts did manage to photograph the package. The pictures showed that the device was in excellent condition. The second experiment of this type, S-12, was attached to the spacecraft and operated by the astronauts by remote control. While Cernan was in the adapter, he heard Stafford close and lock the box. Cernan retrieved the package and stowed it in the spacecraft.
Cameras were the principal instruments used in the last two experiments - S-1, zodiacal light photography, and S-11, airglow horizon photography. Stafford and Cernan took S-11 pictures on three successive night passes, between the 29th and 33rd hours of flight. They got 45 good photographs, under very trying circumstances. The tendency to float upward in zero gravity made pointing the camera and taking the pictures no easy task.
Zodiacal light photography had been scheduled for the space walk. A fogged faceplate, however, was no help in aiming a camera. The pictures had to be taken from inside the spacecraft after Cernan had returned to the more restful confines of his couch. Cernan had to hold the camera against his chest while pointing it out the window at the targets and calling out directions to Stafford for aligning the spacecraft. He obtained 17 good photographs.
On 6 June, during the 45th revolution, they got ready to come home. Gemini IX-A touched down 0.70 kilometers from the planned impact point in the Atlantic Ocean, 72 hours, 20 minutes, and 50 seconds after launch. After scanning the panels in the spacecraft and flipping some switches, the crewmen opened both hatches, relaxed, and watched the gently rolling sea. They were close enough to raise their arms and thumb a ride on the Wasp. Stafford and Cernan stayed in their spacecraft until it was hoisted onto the ship's deck. After the usual hullabaloo had subsided, Cernan told anyone who would listen to him that extravehicular activity was not easy, not nearly as easy as people believed. And he seemed bitterly disappointed that he had been unable to fly the Air Force's maneuvering unit.
To the public, the frustrations of Gemini XI-A - the formidable shroud and the fogged faceplate - overshadowed its accomplishments. Flying formation with and examining an unstable body had been a useful experience. Of even more significance were the advanced rendezvous maneuvers, proving that the flight controller and crews could handle sophisticated rendezvous techniques that might be applicable to Apollo. Had Gemini IX-A been VIII, the results might have been viewed differently - as just part of the learning process. But docking, a primary objective, had not been achieved; and extravehicular activity had not succeeded in evaluating the maneuvering unit. Some engineers in MSC Crew Systems Division thought too much was being tried too soon - the simpler maneuvering unit planned for Gemini VIII would have been the logical second step in mastering EVA. As it turned out, the cliche to "watch out for that second step" would have made a good motto, but the step was greater than anyone had yet realized. References: 1 , 2 , 5 , 6 , 26 , 33 , 60 .