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'A Finite Number of Heartbeats': The Trauma of Gemini VIII (Part 1)
By Ben Evans, on March 15th, 2014


Neil Armstrong (left) and Dave Scott sought to fulfil many of the objectives needed to reach the Moon, including orbital rendezvous and docking. They were the only Gemini crew whose two members both walked on the Moon later in their careers. Photo Credit: NASA

At the dawn of 1966, America’s drive to land a man on the Moon had accelerated into high gear. Five Gemini crews had shown that astronauts could survive in space for long enough to complete the journey and that it was possible to venture outside in a pressurized suit and perfect the tricky technique of orbital rendezvous—all of which would someday be critical in enabling the first steps on another world. On Gemini VIII in March 1966, astronauts Neil Armstrong and Dave Scott sought to press the envelope still further. They would spend three days in space, perform rendezvous and—for the first time—actual physical docking with another object, and execute combined maneuvers, scientific experiments, a two-hour EVA, and a precision re-entry and splashdown. In time, Armstrong and Scott would both leave their bootprints on the dusty lunar surface … yet their ill-fated flight together on Gemini VIII would bring them within a whisker of losing their lives.     

The pair had been together since the end of August 1965, and neither man was under any illusion about the complexity of their task. The EVA was particularly crucial. Unlike America’s first spacewalker, Ed White, who had moved around for barely a few minutes, Dave Scott would maneuver to the rear of Gemini VIII, reverse himself into a backpack, known as the Extravehicular Support Package (ESP), and attach a tether to enable him to venture up to 90 feet away. He would spacewalk through orbital daytime and nighttime, retrieve an emulsion package, activate a micrometeoroid collector on the Agena target spacecraft, and test a reactionless power wrench. It was only the second time an American had left his craft in space, and Scott’s work was laden with risk; if he hit difficulties, there would be no way for Armstrong to see or reach him. Aware of this risk, Armstrong had requested realistic training models of the Gemini’s aft adaptor section and a series of rehearsals in an altitude chamber. By the eve of launch, Scott had practiced his movements on 200 parabolic aircraft flights and more than 20 hours on an air-bearing table.

Scott knew that to operate effectively within a space suit he needed to maintain his physical fitness and strength. This was particularly true from conversations with Ed White, who had experienced difficulty closing the Gemini’s hatch at the end of his own EVA. A lever had been fitted to make it a bit easier, but White cautioned Scott that the suit was stiff and heavy and demanded enormous reserves of stamina for any movement, let alone two hours of physical work. Scott jogged, played handball, and pumped iron in the gym, and this brought him face to face with Neil Armstrong’s wry humor. When it came to physical exertion, Armstrong had one cardinal rule: Human beings had a finite number of heartbeats and should not waste them with frivolity! One day, during Gemini VIII training, as a sweat-drenched Scott worked out, Armstrong set the exercise bicycle on its lowest possible setting and began pedaling. …



Gemini VIII was launched on 16 March 1966, atop a Titan II booster, from Pad 19 at Cape Kennedy. Photo Credit: NASA

The training uncovered obstacles that might have threatened Scott’s life. The air-bearing table, for example, allowed him to literally “fly” across a surface and demonstrate a hand-held maneuvering gun. The gun was filled with Freon, a relatively dense refrigerant, and the strength of its impulse caused Scott to worry about how it might perform in space. In one test at low temperatures, the Freon caused the gun’s poppet valve to stick “open” when triggered. Had this occurred in the frigid cold of orbital flight, the escaping gas might have caused Scott to tumble uncontrollably. Elsewhere, there were concerns that an injector in the space suit’s chest pack might freeze and prevent the flow of oxygen, and trials inside the cramped Gemini cabin left some engineers literally “tangling” with the problem of a jumble of floating umbilicals, tethers, and jumper cables. Not until December 1965 did Scott feel confident that he could complete the task.

On the morning of 16 March 1966, the two astronauts awoke in their crew quarters at Cape Kennedy and breakfasted on filet mignon, eggs, and toast with butter and jelly. The skies above Cape Kennedy were clear, blue, and cloud-speckled, and conditions seemed perfect for the launch of their Agena-D target vehicle—a pencil-shaped craft, mounted atop an Atlas rocket—at 10:00 a.m. EST and their own launch at 11:40 a.m. As they donned their suits, a watch belonging to aviation pioneer Jimmy Mattern was strapped around Armstrong’s wrist, and pieces of wood and cloth from an old Douglas World Cruiser, the New Orleans, were packed with Scott’s personal effects. Both were on loan from the museum at Wright-Patterson Air Force Base. At Pad 19, where Gemini VIII sat atop its Titan II booster, a glitch with Scott’s parachute harness required backup commander Charles “Pete” Conrad to ferret around for a toothpick to remove epoxy resin from the catcher mechanism.

As the clock struck 10, the Atlas-Agena combination thundered away from Pad 14, inserting the vehicle perfectly into orbit. By now alone in the cramped cabin of Gemini VIII, the astronauts were elated. The first stage of their mission was running smoothly. “Cradled in my contoured seat,” Dave Scott wrote in his autobiography, Two Sides of the Moon, “it felt almost as if I was being held in someone’s arms.” The Gemini felt as snug and crisp as a brand-new Ferrari, and the pure oxygen atmosphere provided a cool sense of freshness and cleanness to the cabin.

Under the direction of Flight Director John Hodge, Gemini VIII itself rose from the pad at 11:41 a.m. The astronauts felt  “a solid feeling, a sharp kick in the tail” as the Titan delivered them smoothly into space. Scott’s heart rate peaked at 128 beats per minute, with Armstrong’s reaching 146; post-mission analysis would determine that the difference was attributable to a “keying-up” of the commander’s physical and psychological awareness, rather than an indicator of undue stress. Armstrong told his biographer, James Hansen, that the ascent was “very definite” and that although the Titan’s thrust was noticeable, it did not interfere with their communications. By the time the first stage separated and the second stage ignited, Scott described the ride as “smooth as glass” and, minutes later, was amused to let go of his checklist and watch it drift across the cabin … together with a small metal washer which hovered in front of his face.

Nothing could have prepared either man for his first glimpse of Earth. By now they had crossed the vast gulf of the Atlantic Ocean, and as Armstrong rolled Gemini VIII they beheld the deep trench of the Mediterranean Sea, with Italy clearly visible, and far on the horizon the unmistakable shapes of the Middle East and the Red Sea. In those euphoric seconds, Scott realised that his camera would do no justice to this scene; privately he hoped that NASA would someday send an artist or a poet into orbit to describe it better. Nonetheless, he broke out his camera and starting shooting. Armstrong, too, was overwhelmed. He had flown the X-15 rocket aircraft to an altitude of more than 40 miles (64 km) and had seen the curvature of the Home Planet, but this was four times higher and something quite different.



Gemini VIII’s target, the Agena vehicle, is launched from Cape Kennedy atop an Atlas rocket on 16 March 1966. Photo Credit: NASA

There was little time to gaze in wonder at the astonishing scene. Armstrong and Scott were trailing the Agena by a little over 1,000 miles (1,600 km), and they were scheduled to rendezvous and dock with it, later that same day, before performing the EVA. Ninety minutes into the mission, they fired Gemini VIII’s thrusters to slightly lower their orbital apogee. A second burn raised their perigee and a third, at 2:27 p.m., placed them into roughly the same orbital plane as the Agena. “A fundamental requirement of rendezvous,” Armstrong told Hansen, “is to get your orbit into the same plane as the target’s orbit, because if you’re misaligned by even a few degrees, your spacecraft won’t have enough fuel to get to its rendezvous target.” By launching in a tightly defined time span and entering orbit within a few tenths of a degree of the target, Gemini VIII was thus poised. Betwixt the thrusters burns, Armstrong and Scott broke for lunch … and broke would probably be an apt choice of word. Space food was hardly home cooking. The chicken and gravy casserole, despite having been rehydrated, was quite dry, and the men’s chocolate brownie cookies stuck together and crumbled apart. Fortunately, they were running on reserves of adrenaline and eating was the last thing on their mind.

At length, the Agena was detected by radar at a distance of about 200 miles (320 km), and another burn of Gemini VIII’s thrusters, high above Madagascar, aligned them with perfection for the “terminal” phase of the rendezvous. An hour later, at 4:21 p.m., Scott visually sighted the target, less than 80 miles (130 km) away, its rendezvous beacon blinking against the black sky. Drifting into orbital nighttime, they lost sight of it for a while, although its beacon was still apparent, and when they re-established visual contact Armstrong prepared for docking. He was now braking Gemini VIII by eyesight alone, firing off short spurts of the thrusters … and, at length, the men’s craft came into position, close to the Agena, with no relative velocity. Thirty minutes later, after checking that the target was undamaged, they prepared to move in for the final rendezvous and docking.



Gemini VIII’s nose edges into the docking collar of the Agena target. Although this mission achieved a successful rendezvous and docking, it fell victim to violent oscillations, due to a stuck-on thruster, which almost cost Neil Armstrong and Dave Scott their lives. Photo Credit: NASA

The complexity and importance of this maneuver cannot be underestimated. No previous physical docking had ever been accomplished by a manned craft, and, with NASA planning Lunar Orbital Rendezvous as part of its scheme to land on the Moon, the work of Armstrong and Scott was absolutely critical. As the commander guided his ship gingerly closer, he experienced no problems; in fact, fellow astronaut Wally Schirra—who performed a rendezvous the previous December—had assured him that flying close to another vehicle was very easy when the correct positioning had been achieved. For 25 minutes, Armstrong and Scott electronically checked the Agena’s systems, antennas, and lights by radio command and by now were so close that they could read a small instrument panel above its docking collar. At 6:15 p.m., less than seven hours after launch, Armstrong became the first human being to dock with another craft in orbit. An electronic motor aboard the Agena retracted the collar, pulled the Gemini’s nose into the target, and connected their electrical systems. The instrument panel on the Agena displayed a green “rigid” confirmation.

Both vehicles were electrically and mechanically mated. They had done it.

“Flight, we are docked,” Armstrong announced, with more than a hint of triumph, “and it’s really a smoothie!” There was no noticeable oscillations in the combined craft. In the Mission Operations Control Room in Houston sheer pandemonium broke out. The achievement of Gemini VIII had cleared another hurdle on the road to the Moon.

Armstrong’s “smoothie,” though, would be the last time that anyone on the ground or in orbit would breathe easily. Within minutes, Gemini VIII would change from a perfect flight into a very real battle for survival.


Source: https://www.americaspace.com/2014/03/15/a-finite-number-of-heartbeats-the-trauma-of-gemini-viii-part-1/

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'Tumbling End Over End': The Trauma of Gemini VIII (Part 2)
By Ben Evans, on March 16th, 2014 [AmericaSpace]


Dave Scott (left) and Neil Armstrong breathe the fresh air of Earth as the hatches of Gemini VIII are opened by a trio of U.S. Air Force Pararescuemen (PJs) after splashdown. Photo Credit: NASA

Forty-eight years ago today, Gemini VIII astronauts Neil Armstrong and Dave Scott accomplished a key goal in America’s bid to land a man on the Moon by successfully rendezvousing and docking with an unmanned Agena target vehicle in Earth orbit. As noted in yesterday’s AmericaSpace article, it was the first time that a manned vehicle had achieved physical contact with another target in space. However, the situation aboard Gemini VIII was far from perfect. A distinct lack of available tracking stations across the flight path had already resulted in decidedly “spotty” communications with the Mission Operations Control Room (MOCR) in Houston, Texas. In fact, only two ship-based stations were supporting the flight, the Rose Knot Victor and the Coastal Sentry Quebec, together with a land site in Hawaii. Shortly before one loss of contact, at around 6:35 p.m. EST on 16 March 1966, Capcom Jim Lovell radioed the Gemini VIII crew. If problems arose, he told them, they should immediately deactivate the Agena with Command 400 and assume manual control with the Gemini. It was a standard call. Lovell could hardly have imagined that a potential disaster would soon engulf the mission.   

Half an hour after docking with the Agena, Dave Scott instructed the target to roll them 90 degrees, and Neil Armstrong, in the commander’s seat, told Lovell that it had “gone quite well.” The call came a few seconds before Gemini VIII passed out of radio contact with the ground. Alone, the astronauts electronically activated the Agena’s tape recorder. Shortly thereafter, their attitude indicator showed that they were in an unexpected, and almost imperceptible, roll of about 30 degrees. “Neil,” called Scott, “we’re in a bank.” Were the Agena’s attitude controls misbehaving? Or was it a problem with the target vehicle’s software? Certainly, Gemini VIII’s own thrusters were now switched off and the assumption could safely be made that the Agena was at fault. What they did not know was that one of their thrusters—the No. 8 thruster—had short-circuited and stuck into its “on” position. Unaware, Scott cut off the Agena’s thrusters, whilst Armstrong reactivated the Gemini’s thrusters in an attempt to stop the roll and bring the combination under control.

For a few minutes, his effort succeeded.

Gradually, the craft stabilized. Then, as Armstrong started to reorient them into their correct position, the unwanted motions resumed … albeit much faster than before and along all three axes. Perplexed, the men jiggled the Agena’s control switches, then those of the Gemini, on and off, in a fruitless attempt to isolate the problem. Glancing at his instrument panel, Scott noticed that their craft’s attitude propellant had dropped to just 30 percent. At this stage, it dawned on the astronauts that the fault was with their craft. “We had to disengage from the Agena,” Scott later wrote in his memoir, Two Sides of the Moon, “and quickly.”

This posed its own problems, since both craft were rapidly rotating and could hit each other. Quickly, Scott set the Agena’s recording devices to allow flight controllers to remotely command it; a crucial step, since, after undocking, the target would otherwise be dead. “No one would ever know what the problem had been or how to fix it,” he wrote. His prompt action saved the Agena and preserved it not only for subsequent investigations, but also for a remarkable “double rendezvous” on the Gemini X mission in July.

Armstrong and Scott were still out of radio communications with the ground. They duly undocked from the Agena and fired a long burst of the Gemini’s thrusters to pull away … whereupon their craft, now free, began to spin much more violently, in roll, pitch, and yaw axes. Since the stuck-on No. 8 thruster was no longer turning the entire combination, the oscillations were correspondingly worse than before. At length, high above southeast Asia, they came into contact with the Coastal Sentry Quebec. Controllers were stunned at 6:58 p.m. when Dave Scott’s urgent call came through.

“We have serious problems here,” he reported. “We’re tumbling, end over end. We’re disengaged from the Agena.”

Jim Fucci, the communicator aboard the ship, was stunned and asked them about the problem. Quickly, and characteristically calm, Armstrong reported that they were continuously increasing in a left roll and unable to turn anything off. Fucci, an old NASA hand with great experience, alerted Houston that Gemini VIII was suffering from “pretty violent oscillations.” The resultant three-way conversation with the MOCR meant that several seconds elapsed before Flight Director John Hodge picked up all the details; Fucci had to repeat that Armstrong was “in a roll and he can’t stop it.”

In orbit, Armstrong threw circuit breakers to cut electrical power and hence the flow of propellant to the attitude thrusters, including troublesome No. 8. However, with no friction or counter-firing thrusters to halt it, the spinning continued … reaching a horrifying 60 revolutions per minute. Checklists, flight plans, and procedural charts were flung around Gemini VIII’s cabin by the resultant centrifugal force, and the unfiltered sunlight blazed through the astronauts’ windows with startling regularity. To Dave Scott, it was like a constant strobe light, hitting them square in the face. Added to this, the rotation was such that the astronauts were close to physically blacking out and they struggled to read their instruments. Physiologically, Armstrong and Scott were suffering from a complete loss of orientation, caused by the effect on their inner ears, together with an involuntary rhythmic motion of their eyes.



Gemini VIII (foreground) enters into the final stages of rendezvous with the Agena target vehicle. Photo Credit: NASA

Aware that the problem was with his own spacecraft, Armstrong had little choice but to use Gemini VIII’s 16 re-entry thrusters to steady them. This was easier said than done … for the re-entry controls were in a particularly awkward position, directly above his head, and, worse, they were on a panel with around a dozen toggles. “With our vision beginning to blur,” wrote Scott, “locating the right switch was not simple.” Fortunately, months of repetitive training had allowed the astronauts to know each switch, intuitively, but Scott was amazed at Armstrong’s flying skill as he reached for the toggle and grappled with the spacecraft’s hand controller, at the same time. Eventually, the effort succeeded, albeit at the expense of 75 percent of Gemini VIII’s propellant. Mission rules decreed that, once the re-entry controls had been activated, the flight was aborted. Ten hours into a planned three-day mission, Armstrong and Scott were on their way home.

Television stations began interrupting their programmes—Batman and, ironically, Lost in Space—to provide live coverage. Original plans had called for Gemini VIII to splash down in the Atlantic and be recovered by the aircraft carrier U.S.S. Boxer, but the emergency guided them instead to a point in the western Pacific, 500 miles (800 km) east of Okinawa. A naval destroyer, the U.S.S. Leonard F. Mason, based off the coast of Vietnam, was assigned to this splashdown zone and her crew began steaming toward the predicted point.

The bitterly disappointed astronauts ran through their pre-retrofire checklist, and tests of Gemini VIII’s thrusters finally identified the fault with No. 8. Scott later described the thrusters as not exhibiting “a consistent, linear problem … it was really screwed up.” In effect, the thruster had been “on” when it should have been “off” and vice versa. Loading the re-entry software into the spacecraft’s 4,000-word computer memory was difficult, particularly as it was already overloaded from the rendezvous with the Agena. This required Scott to erase the rendezvous and docking programs and feed the re-entry data by means of a keypad and auxiliary tape memory unit. Punching in a series of nine lines of seven-digit numbers, he checked and cross-checked his work with Jim Fucci, whose admirable calmness under duress made those critical moments seem like “taking a stroll in the park.”

At 9:45 p.m., Gemini VIII’s retrorockets fired above south-central Africa, in orbital darkness, which gave the astronauts no visual cues for alignment. The spacecraft re-entered over the high peaks of the Himalayas, and, as it descended, Scott could see nothing through his window, save a pinkish-orange glow of superheated plasma outside … then, after a while, came high-level haze and, later, the glint of water. Ten hours and 41 minutes after leaving Cape Kennedy—at 10:22 p.m. on 16 March in Florida, but a little after midday on 17 March in the western Pacific—Gemini VIII hit the choppy waters with a harsh thump. Seasickness was an inevitability as the spacecraft’s windows rhythmically rolled and pitched, but the men stepped smartly through the shutdown of electrical and other systems. They had forgotten to take their anti-seasickness pills. “When Mission Control told us about three-foot waves,” Scott recalled, “they forgot to mention the 20-foot swells!”

First on the scene were U.S. Air Force Pararescuemen (PJs) from 33 Air Rescue Service, scrambled out of Naha Air Force Base, Okinawa, aboard a Grumman HU-16 Albatross flying boat. They successfully parachuted into the Pacific Ocean, applied the capsule flotation collar to stabilize Gemini VIII and were first to tend to the immediate medical needs of Armstrong and Scott. They were followed, several hours later, by the arrival of the Mason. In fact, the destroyer’s crew had been less than enamored when they were assigned to be one of the backup recovery vessels. They had just finished a seven-week tour in Vietnam and had been given a brief spell of liberty in Okinawa. Now they were as relieved as the rest of the world that Armstrong and Scott were safe.

In the weeks that followed, post-flight analysis removed any blame from the shoulders of the astronauts. Still, astronauts Walt Cunningham and Tom Stafford expressed criticism; the former pointed to flaws in both Armstrong and Scott’s performance, and the latter argued that undocking from the Agena had been the wrong decision. Flight Director Gene Kranz, who supervised Gemini VIII’s re-entry, saw things differently. He regarded it as a failure of the ground controllers in having few contingency procedures to cover the docked phase of the mission. Other astronauts, including Frank Borman and Wally Schirra, praised the actions of the crew as having saved the mission from disaster. Without their safe return, the erroneous belief that the Agena was to blame could have diseased Project Gemini’s final months and made it difficult for Project Apollo—with its emphasis on rendezvous and docking—to move confidently ahead. In Scott’s words, it could have been “a showstopper.”

The performance of Neil Armstrong and Dave Scott in March 1966 was nothing short of remarkable. They had completed a flawless docking with the Agena and, but for the stuck-on No. 8 thruster, might have gone on to complete an equally flawless three-day mission. That neither man was to blame for the events of Gemini VIII is amply highlighted by their subsequent careers: Armstrong was reassigned as backup commander of Gemini XI, whilst Scott was named as senior pilot on the backup crew for the first manned Apollo mission. In time, they would venture further, becoming the only Gemini crew whose both members would someday set foot on the Moon.


The author would like to express grateful thanks to Mr. Jeff Morrisette (SGT USAF, CDR USN, Ret.) for his clarification and additional detail regarding the critical role of U.S. Air Force Pararescuemen (PJs) in the safe recovery of the Gemini VIII.

Source: https://www.americaspace.com/2014/03/16/tumbling-end-over-end-the-trauma-of-gemini-viii-part-2/