Space: SPACE The Fuel-Cell Flight

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It was scheduled to be the longest space flight on record. It almost became one of the shortest. And the threat to the ambitious mission became doubly dramatic as the fortunes of Gemini 5 oscillated wildly last week between disaster and promise, perfection and near-fatal flaw.

Lift-off from Cape Kennedy, when it finally came, was timed to the second. The countdown clock had not been stopped once−a truly remarkable demonstration of cooperation between men and intricate machines. Rising above its roaring tail in textbook exactitude, the booster flung its capsule aloft with a heart-stopping burst of power. Ahead were eight orbital days−eight days that would, if all went well, teach man more than he had ever known before about the problems and possibilities of flight in space.

Bad luck seemed behind the spacecraft at last. Forgotten for the moment was the mare’s nest of trouble that had postponed the flight for two days. Fuel cells running low on fuel, liquid hydrogen boiling uselessly away, telemetering equipment turned suddenly unreliable, fire near the launch pad, thunderstorms aloft−all seemed problems of the past. Now everything was going well; Gemini’s orbit was incredibly exact. “Everything is fine,” reported Command Pilot Gordon Cooper. “You are go! You are go!” exulted Astronaut Jim McDivitt, capsule communicator in the Mission Control Center near Houston.

Dropping Pressure. At 56 minutes after launch, Cooper began the mission’s first important maneuver. By firing his aft thrusters at just the right moment for just the right length of time, he gave his craft a “kick in the apogee” and moved it into an even more precise orbit. Curving between 107 and 217 miles above the earth, Gemini wasnow ready for its next test: release of the 76-Ib. Radar Evaluation Pod (REP). Fitted with bright, flashing lights and radar transponders, the REP would be an orbiting target for a carefully planned attempt to check the techniques of docking vehicles in space.

But even before REP could be released, there was an ominous hint that the mission might be going sour once more. In the final minutes of the first revolution, as Gemini 5 came within range of the Guaymas tracking station in Mexico, Astronaut Pete Conrad made a calm, almost routine report. The pressure, he said, was dropping in the fuel cells’ oxygen supply. The gauge that normally should have read 800 to 900 Ibs. per sq. in. was dropping fast. Since the fuel cells were the main source of power for the spacecraft’s communications, computer and environment control system, they were, in effect, the heart of the Gemini mission.

As yet untried in orbit, fuel cells were installed in Gemini 5 because they were smaller and lighter than the conventional batteries used on all previous space flights. Unlike conventional batteries, they can supply electricity for as long as they are fed their fuel−an ideal trait for long-duration power supplies. They produce electricity through the continuous chemical reaction of oxygen and hydrogen, and in the process they form water, a most valuable byproduct.

The cell’s hydrogen and oxygen are both stored in spherical tanks in a supercold liquid state. Warmed by electric heaters, they turn to gas, build up pressure and push themselves into the cells. And those heaters are among the least complicated devices on the spacecraft: a filament of gold-plated wire curving around the tank. The same type of device is a veteran of all the manned Mer cury and Gemini flights, being used to convert liquid oxygen into gas for the astronauts to breathe. When oxygen pressure started falling in Gemini 5, it was a sure sign that for some reason electricity was not heating that vital filament.

Still Safe. Gemini soared into its second orbit. Over Africa, Cooper ejected the Radar Evaluation Pod precisely on schedule. Though the spring release tossed it out a little harder than anticipated, the mission still seemed safe.

But back at NASA’s Houston control room, Flight Director Chris Kraft’s ground crew was growing more and more worried about the unheated fuel for the fuel cells. The pressure kept falling; it was already dangerously low at 180 p.s.i. Because the radar, radio and computer would use up too much power, Chris Kraft decided against any further maneuvers with the pod. He went into a huddle with his fuel-cell engineers Assured that the pressure was far too low for normal operation, Kraft immediately planned for the crew’s safety.

Against the growing probability that the mission would have to be aborted early, he ordered four Air Force planes to move into position in the Pacific for a possible emergency splashdown some 490 miles north and east of Hawaii. A Navy destroyer and oiler in the vicinity were alerted to stand by. Radioed Cooper: “We’ve decided we’re going to have to either re-enter early or else power down.” Kraft promptly ordered him to shut off as many systems as possible. Was the rendezvous with the pod still possible? asked the astronauts. “We’re working on a new flight plan for you,” answered Kraft.

Anxious Quiet. Following instructions from Houston, Cooper and Conrad worked desperately to rejuvenate the balky fuel-cell system. Neither the automatic nor the manual controls for the oxygen tank heater would function. And getting at the heater itself was out of the question. Located in the adapter section, it was inaccessible to the crew. The astronauts flicked switches off and on again and again, trying somehow to stir the system into life. They maneuvered the spacecraft around so chat its blunt end, which housed the fuel-cell system, would get the full impact of the sun’s rays. But the sun was no help. By this time the astronauts had turned off the radar, radio, computer and some of the environment-control systems. They were consuming only 13 amperes of electricity−but that was all that the fuel cells were producing.

An anxious quiet set in as Gemini 5 swept over the Atlantic on the beginning of its third revolution. Along with most of the U.S., the astronauts’ families huddled close to their TV sets, waiting for some word. Almost everyone was convinced that the spacecraft would have to be brought down during the sixth revolution, before its orbital track took it away from the Pacific recovery area that would be its last convenient rescue location for many hours.

When the astronauts passed over the tracking station at Tananarive in the Malagasy Republic, they were called by Mission Control. Kraft, who usually passes on instructions only through the capsule communicator, went on the air himself. “What is your pressure reading now?” he asked. One hundred and twenty to 125 Ibs., came the answer. “It looks like the rate of decrease is decreasing,” observed Kraft, hoping to hearten the crew. He told them that airplanes were on their way to the Pacific recovery area, adding, “We hope we don’t have to use them, but it will be a good exercise for them, and they’ll be there if you need them.” While they talked, though, the oxygen pressure dropped still lower−to 95 Ibs. If it fell to 20 Ibs., the spacecraft would have to switch to its back-up batteries, which produce just enough power to handle an orbit and a half, plus re-entry and recovery time.

Please Acknowledge. During the next pass over the U.S., the astronauts were ordered to cut off one of the two fuel cells, in the hope that the maneuver might help the ailing system. The fourth revolution was even quieter than the third. The astronauts were instructed: “If you have had a significant pressure rise, please turn your transmitter up and acknowledge.” There was no acknowledgement. The pressure had leveled out at 71 Ibs. The sixth revolution was coming up fast, and a decision had to be made soon. If recovery were delayed even one revolution longer, Gemini would not be over a convenient landing area for another 18 hours.

Kraft told Capsule Communicator McDivitt to raise the capsule on the radio and explain the problems and possibilities for going beyond the sixth orbit.

CapCom to Cooper: I would like your opinion on going through another day under these circumstances.

Cooper: We might as well try it.

CapCom: O.K. We will look at this thing for another orbit.

As Gemini 5 sailed off over the South Atlantic on its fifth revolution, Kraft faced his responsibility. Go? Or no go? Should he bring his ship down or reach for 18 revolutions? If he aborted the flight now, the astronauts would land in the Pacific recovery area where there were no helicopters within reach. At 18 revolutions, the spacecraft could splash down southwest of Bermuda, in the primary recovery area. The flight director called in his engineers, conferred with top NASA brass. Pride and prestige were involved; no manned U.S. spacecraft had ever failed to complete its planned mission. But Kraft, as ever, was the cool and deliberate flight engineer. He used every available moment to weigh every contingency. He ran a check of the spacecraft. All the key systems, such as cabin pressure, oxygen flow and cabin and suit temperature, were normal and running perfectly.

Why Settle for Six? By this time Kraft and his experts were satisfied that the oxygen pressure had stabilized at 71 Ibs. With no further drop, the spacecraft would still have enough electricity for a “drifting flight.” There would be power for only a few experiments, but the risk to the astronauts was slight. Said Kraft later: “We decided we were in reasonably good shape−that we had the minimum power we needed, and that there was a chance the problem might straighten itself out.” Why settle for six, when 18 or more revolutions seemed possible? Chris Kraft relayed his “go” decision to the astronauts as they arced over Hawaii on their fifth circuit of the earth.

Calm & Steady. The decision was a matter of hardheaded determination. With the guts to gamble after carefully considering the odds, Kraft and his ground controllers kept Gemini 5 up in the air, and they kept its chances of success very much alive. Their measured confidence in themselves, their machines and their spacemen was a testament to the considerable achievements of the space age−it was a reminder of how much man has learned about the arcane art of operating in the cold reaches beyond his own atmosphere. The spirits of the Gemini 5 astronauts were buoyed by the chance to go on. For Gordo Cooper, 38, father of two, an Oklahoma-born lieutenant colonel in the Air Force and one of the original seven astronauts, the delays and difficulties had been a familiar part of the business. He had waited out a one-day delay before making his 22-orbit Mercury flight in Faith 7. To Pete Conrad, 35, though, it was all new. A Navy lieutenant commander and father of four, Conrad started flying lessons back home in Pennsylvania when he was only 13. It was, in fact, his first trip into space. But like Space Veteran Cooper, he was steady and calm. Shortly before the first launch attempt was scrubbed, he could joke about the gathering clouds and ask for permission to turn on the windshield wipers−which spacecraft do not have.

If Cooper and Conrad kept their aplomb, it was also obvious that theirs would be a silent journey. There was not enough power for the easy banter, wide-eyed exclamations and cheery hellos to Perth. The fuel cell was generating only 11 amperes of power, and the only systems left operating were the pumps to cool the spacecraft, the suit fans, the air-filtration fans, a power converter, the receiver that takes commands from the computer on the ground, and one radio receiver for getting messages from the ground. They turned on their own radio transmitter and radar beacon only when they crossed over the tracking stations.

Disappearing Pod. The Gemini 5 mission, to be sure, will not be able to accomplish everything it set out to do−no matter how many times it circles the earth. Because of the strict rationing of power, Gemini will be forced to forgo some of the 17 scientific, engineering and military experiments it was supposed to carry out. Though the rendezvous pod kept Gemini 5 company up until the eighth revolution, the astronauts were unable to do anything about it. Once, the pod was sighted within a thousand feet of the spacecraft. Another time, on the sixth revolution, Cooper reported: “That thing’s right with us. It has been all along−right out in back of us.” Then two revolutions later, on an order from the ground, Conrad turned the spacecraft a full 360°, looking for the pod. It had disappeared.

But the rendezvous exercise was by no means a complete failure. After the ejection of the pod, the spacecraft radar received the range of the pod for 43 minutes. This should furnish valuable data on the system’s capabilities and limitations that will help Gemini 6 in its planned rendezvous and docking exercise next October.

Primary Objective. The more revolutions Gemini 5 makes, the more likely it is to fulfill its primary objective of determining the effects on man of long travel in space. Asleep or awake, at lift-off and in orbit, the two astronauts were constantly being monitored by the doctors at the Manned Spacecraft Center, led by Dr. Charles A. Berry, 41, the chief space-flight surgeon. Wavy lines flickering across the oscilloscope on the flight surgeon’s console represented the astronauts’ heartbeats. Data also streamed in giving their pulse rates, blood pressure and respiration.

Such medical monitoring is necessary to determine how well man holds up under the G forces of lift-off and reentry, prolonged confinement in the cramped spacecraft, and the strange effects of weightlessness during flight. When Gemini 5 does come down, Berry plans to run both astronauts through the longest and most intensive postflight medical examinations ever made thus far. Besides checking for dehydration, shifts in blood volume and possible decalcification of the bones, he is particularly concerned about the problem of orthostatic hypotension, which is created by weightlessness. The symptoms: a sharp increase in the heartbeat and a drop in blood pressure on return to earth. If sharp enough, they could cause the astronaut to black out. As an experiment, Berry fitted Conrad with a pneumatic, blood pressure-like cuff around each thigh. The cuffs inflate and deflate automatically for two minutes of every six during the entire mission. Thus, by impeding the flow of blood, they force the heart to pump harder and get its much-needed exercise. If Conrad comes through in better physical shape than Cooper, who is not wearing the cuffs, Berry may have the solution to orthostatic hypotension.

The Longer the Better. With each revolution after the crucial sixth, the hopes at Mission Control soared. The flight of Gemini 5, they speculated, might go eight days after all. Relaxed and grinning, wearing a silver Gemini pin in his lapel, Chris Kraft held his first press conference of the mission. “We have reasonably good confidence,” said he, “that we’re going to be able to go on and complete the intended duration of this flight. He had just made one of the toughest decisions of his career, he was confident he had made the right one, and with each passing hour, each passing day that the spacecraft stayed aloft, he was proven correct. Gemini looked ready to finish its mission. “The longer we go,” said Kraft, “the better off we are.”