Back to the Moon-ARC

by Travis S. Taylor; Les Johnson

  “You should be seeing something. The propellant in the tanks is starting to drop rapidly,” Stubborn Stu said calmly. “You still have plenty remaining, but I’m definitely seeing it.” He, like just about everyone else in the room, was starting to perspire. It was a stereotypically hot Houston afternoon in a room with stereotypically cold Houston air-conditioning doing nothing to prevent the perspiration from coming. It just made the sweat feel uncomfortably cold.

  The sweat starting to bead on Bill’s forehead glistened in the control-room lighting. He kept a watch on the laser-ranger data, and finally the velocity numbers began to decrease. The velocity dropped from an excess of five meters per second to four. Then to three and finally to a closure rate that should permit safe docking. This happened not a minute too soon—as Stetson fought to bring the closure velocity down, the distance between the Orion and the EDS continued to dwindle. They were now only a hundred meters away from one another and in desperate need of fine guidance for the final rendezvous. This, too, was a maneuver that the team in mission control had practiced manually, and their training not only took over for these last few minutes of the rendezvous, but it alleviated the stress and allowed the heart rates of the console techs to fall back to normal.

  “We have manual docking in three…two…one.” Marianne Thomas provided the countdown. Bill could tell from the tone in her voice that she was grateful he had overcome the problem and that it wasn’t something she’d done. He figured that the engineer already was beginning the mental construction of a fault tree that would help the mission-review team find out why the automated system had failed and why the GPS data was suddenly blank.

  “Phew,” Stetson said, relieved at completing the docking maneuver successfully. He then declared, “We’re not finished here yet, people. Need I remind you, we’ve got a vehicle that needs to be checked out and sent on its way to the Moon. No dinner and bar just yet.” And he knew that he was correct. If nothing else went wrong, the flight was supposed to continue to the Moon, with the EDS lighting its engines to escape Earth’s gravity in just a few hours.

  The two concurrent failures still needed to be explained and corrected. While the GPS measurements would be useless at the Moon—which had no Global Positioning System satellites—the onboard computer that was supposed to make sense of the laser-ranging data would be used again when the Altair lunar lander returned from the surface of the Moon to rendezvous and dock with the Orion in lunar orbit, allowing the crew to transfer back to the Orion for their trip home. Yes, this was an unmanned test flight, but the systems nonetheless had to work or the launch of the actual mission would be postponed indefinitely until the problem was resolved. The public and political pressure was mounting to kill the space program, and having to scrub so close to launch could be a public-relations nightmare. Bill hoped to circumvent all that.

  The decision to continue the mission or not would have to be made within hours or the liquid-hydrogen supply would boil away uselessly into space. That would give the ground-support team at least a few days to troubleshoot the automated rendezvous and docking system, and its computer and software, to find the source of the problem and hopefully fix it. At least, that’s the logic Stetson was using when he made the decision that only he could make.

  “All right, everyone, we’re go for Lunar Orbit Insertion unless and until I say otherwise. We’ll get this problem fixed and patched before it’s needed again. Let’s stay the course.” In his unflappable way, which was one of the reasons he had been selected to be the commander of the first human lunar return flight, Stetson both committed the mission to the next phase and reassured all in the room of the can-do attitude that was so crucial to past mission successes, had been missing at NASA for decades, and, while on his watch, was absolutely crucial to the current mission—his mission. Bill was going to go to the Moon or bust.

  Chapter 2

  The cause of the rendezvous and docking failure was still unknown, but virtually every member of the team that developed the system and its flight computer were called in to begin working on understanding the failure and figuring out how to fix it. Rocket scientists and engineers in Houston, Texas, and Huntsville, Alabama, found out that they wouldn’t be going home on time. A flurry of cell-phone calls, e-mails, and text messages to spouses or significant others went out explaining that they wouldn’t be home for dinner. Take-out pizza would be the most common meal of the day.

  Thirty-six hours later, the command was given for Lunar Orbit Insertion. In typical NASA fashion, the media were told that all systems were “nominal,” thereby guaranteeing that the viewing public would be put to sleep by the whole event. To those engineers engaged in making it happen, however, “nominal” would not be the word that first came to mind. It certainly wouldn’t be the story they told their families and friends later in the week.

  Upon receiving the command, the EDS fired up its single J-2X cryogenic engine, which began to burn two hundred twenty thousand pounds of hydrogen and oxygen, accelerating the hundred-ton Earth Departure Stage to greater than the twenty-thousand-miles-per-hour velocity required to escape the pull of Earth’s gravity.

  If not for the incredibly cold liquid-hydrogen fuel circulating through the pipes wrapping the outside of the J-2X engine, the hellish six-thousand-degree heat produced by the burning of the hydrogen and oxygen in the combustion chamber would have almost immediately melted the nozzle. The fuel circulated through pumps and around the exterior of the rocket-engine nozzle and then back into the engine, where combustion would take place. The hydrogen and oxygen burned together and forced superheated and pressurized gasses out through the throat of the nozzle to its exit and then into space with a pure bright orange and white fiery glow.

  The J-2 engine originally flew on the second stage of the venerable Saturn V rockets that carried the Apollo astronauts to the Moon. The J-2X was an upgraded version for the new generation of Moon rockets, and it was designed to complete its job in just less than seven minutes of burn time.

  Throughout this acceleration, the Orion continued to perform what was known as the barbeque roll, so-called because it resembled the process of slow-cooking a pig on a spit over an open fire, slowly turning the pig so as to not overcook one side from the intense heat of the flame. The Orion performed this slow roll for the same reason—so as to not cook the ship by having one side of the vehicle continuously exposed to sunlight and therefore becoming a barbeque in space. After all, nobody likes their rocket overcooked on one side and raw on the other, especially not the astronauts inside it.

  In addition, the delicate solar arrays that would power many of the onboard functions, previously unfurled like origami, were rotated so they would continuously point toward the sun. The solar panels were crucial in maintaining the electrical power required to keep the Orion’s systems functioning.

  All of these pointing-and-control maneuvers were controlled by onboard computers. And all of the onboard computers that performed this function had within them a board manufactured by Alcoa Electric Corporation. This same board was used to control the automated rendezvous and docking maneuver between the Orion and the EDS.

  “Bill, I think we’ve got one of the problems figured out.” Stetson, without having to look up from what he was doing, recognized the voice at the door as that of the chief engineer for the rendezvous and docking system. It had been almost two days since the nail-biting Earth-orbit rendezvous of the Orion with the Earth Departure Stage, and no one was really expecting the engineers to figure out the cause of the problem so quickly. Not that Bill Stetson would appear to be surprised by anything.

  “Come in.” Stetson looked up from his desk and motioned for the seasoned but ever-eager Rick Carlton to take a seat at the small conference table across the room. Bill rose from his chair and strode to the table, the alpha male in the room by the way he carried himself and his purposeful stride to the chair adjacent to the one Carlton had just occupied. “What have you got?” he asked.

  C
arlton, no lightweight by anyone’s standards, was intimidated by the astronaut’s presence. Bill could tell, but then he hoped the man would get over it because Bill didn’t go through life trying to intimidate people. It wasn’t his style. He wasn’t trying to be intimidating—he just was. Asking him not to take control over just about any situation in which he found himself would be like asking the sun not to shine. Bill was just one of those people who demanded attention and he usually got it.

  “Uh,” Carlton began his explanation, nervously shuffling the papers he’d brought in with him, “the glitch appears to be in the flight-computer software. You know the software was the tall pole leading up to this flight, and I am surprised the IV&V didn’t catch it long before now.” The NASA Independent Verification and Validation team had the task of approving all flight software. The team’s job was to be another set of eyes to review all the software, line by line, just to make sure it was correct and that there wouldn’t be any major flight-system failure from faulty computer code.

  “Really?”

  “Yeah. The computer is supposed to take all the sensor data from the Orion and route it to the systems that need the information to function. It’s supposed to take data from the laser ranging, the GPS, the sun sensors, and just about every other sensor on the vehicle and make sense of it. Sort it and then funnel it out to the elements that need it next. In our case, however, that didn’t happen.” Carlton paused, and Bill could tell that the pause was not only to take a breath, but also for effect.

  “Why not?” asked Bill, looking at Carlton expectantly but not impatiently.

  “Well,” Carlton began again, “the software got to the computer all right, but the code added the position-error function to the data twice, making its actual position appear to be incorrect, thus causing the ship’s thrusters to overcompensate in an attempt to get it where it was supposed to be—which it already was, at least the first time. Since it didn’t know where it really was, it appeared to be where it was at an earlier time. The thrusters fired to move it to where it was supposed to be, and then the lag happened again. The ship appeared to have not moved or moved only slightly. The thrusters then fired again, making the Orion move faster than it was supposed to in an effort to get to where it thought it should be when, in fact, it was already there.” He began to wonder if his wordy explanation was making any sense.

  “Hmm.” Bill nodded.

  “Are you following me?” Rick Carlton asked, but Bill Stetson was not just following him; he was ahead of him in his thought processes.

  “So, the Orion, thinking it was sitting where it used to be sitting, fired its thrusters to get where it thought it was supposed to be when in fact it was already there. And then it got stuck in this loop, making the ship accelerate when it should have been slowing down. Correct?”

  “Yes.” Carlton, who seemed pleased that Stetson had understood him, nodded and continued. “And then there is the matter of the missing GPS data. Shortly before Earth departure, the data started appearing again. The only thing we can figure is that there is some sort of short in the system. We’ve isolated the problem to a particular circuit board. A loose connector or a lead that wasn’t well potted could have caused it. We still don’t know exactly, but…” He trailed off, lost in thought or perhaps unsure of what he should say next.

  “But what?” Bill asked.

  “Well, the same board is used in several pieces of hardware throughout the Orion and some in the Altair.” Altair was the generic name of the lunar-lander craft, not the name given to any particular lunar lander. “We believe there is a quality problem with this one board, and that’s it. But there is a chance the problem isn’t isolated. If it’s a generic problem with the board’s design, well, then we have a big problem.”

  Stetson knew what that problem would be. If the board’s design was at fault, and it had to be replaced wherever it was used in the entire system, then America’s return to the Moon would be on indefinite hold until a replacement was designed and the entire system assessed for any unforeseen changes that might result. It could mean a mission delay measured in years.

  “Good work, Rick.” Trying to reassure himself as much as Carlton, Stetson added, “Let’s take it one step at a time. Since we can’t look at the board until the Orion returns from the Moon, let’s not sweat it too much. Once the team gets it in front of them on a workbench, they’ll be able to make that call.”

  Carlton stood up, picked up his papers, and started to walk out the door. He almost made it before Stetson called out his name and asked another question.

  “Rick, what other hardware might be affected?”

  “Uh…” Carlton frowned and looked toward his feet before answering. “Lots. The Orion attitude-control system and solar-array pointing system, the Altair attitude-control system, both communications systems, and just about every other piece of hardware that has to be concerned with pointing in one direction or another. It’s all over the place.”

  “Okay. Thanks,” Stetson responded. The tone of his voice conveyed both concern and that the discussion was over.

  “I guess I’ve been dismissed,” Bill overheard the man mutter to himself as he hurried out the door and down the hallway toward his office. Bill paid it no mind at all. He had more important things to deal with.

  Elsewhere, the now-docked Orion and Altair lunar-lander vehicles, thousands of miles away in space, separated from the EDS and began the remaining part of their journey toward the Moon.

  Chapter 3

  “Where’s Bill?” Astronaut Jim England was looking for his longtime friend. England was a tall, lanky man with a noticeable “hillbilly” accent that he seemed able to turn off and on at will depending upon the situation. Presently, his pronunciation of “Bill” would make listeners swear it was a two-syllable word. He’d known Stetson since their first flight to the International Space Station together back in the shuttle days and had immediately become a part of Stetson’s inner circle of close friends. England never seemed to meet anyone he didn’t like, and almost everyone responded to his warm personality by counting him as a friend.

  “Hi, Jim.” Stetson’s secretary looked up from her computer screen at the astronaut. She had been Stetson’s secretary, or, to be politically correct, his management support assistant, for almost five years. Married for over thirty years, with a grandchild on the way, Millie Lawford was cordial, worldly wise, and very good at her job.

  “How’re things?” England asked. “You look perplexed.”

  “Bill’s calendar.” She grunted as she tapped at her keyboard and then clicked her mouse several times. “It’s a frustrating experience that I’d say is more like herding cats while being overrun by mice than trying to actually schedule adult professionals in the same place at the same time.” She managed a smile for England.

  “Ha.” Jim laughed out loud. “Try tuna and milk.”

  “He’s in the office. Shall I tell him you’re here?” She started to rise from her seat.

  “No, that’s okay,” Jim said. “I’ll go on in. Unless you think I shouldn’t?”

  “No, I’m sure it’s fine. Go on in.” She looked back at her screen, forgetting about Jim, and immediately frowned. “NASA just has too many meetings,” she half muttered to herself. “How the heck is he possibly supposed to be in all these places in one short ten-hour day?”

  “Good luck.” England shook his head. Taking her inattention to him as dismissal, he walked up to the closed simulated-wood-grain door to Bill Stetson’s all-too-government-issue office. He knocked on the door and reached to open it in one quick, fluid motion. If Stetson were doing something that he didn’t want anyone to see, then he would certainly be caught by surprise.

  Fortunately, Stetson was simply sitting at his desk looking at his thirty-inch computer monitor with a mild grin upon his face. He looked up and motioned for Jim to join him on the other side of the desk.

  Stetson, though an astronaut and commander of the next flight to the Moo
n, the first flight “back to the Moon,” was still only a civil servant and subject to civil-service rules regarding office space and accoutrements. The simulated-wood-grain desk and generic cream-colored filing cabinets were the primary features of the room. On the walls were framed pictures of a shuttle launch, the International Space Station, Stetson floating in the U.S. Laboratory Module of the ISS, and many, many pictures of his wife and two children. In the family photos, there were none that didn’t have Stetson surrounded by the satellites that were his family. And in all of them, his wife and children wore great big smiles.

  Jim rounded the corner of the desk and heard a voice talking from what sounded like a deep well. The audio was crackly. He knew what he was listening to an instant before he saw the screen and had his guess confirmed. From the speakers came “…forged man’s destiny of tomorrow. And, as we leave the Moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind. Godspeed the crew of Apollo 17.” The voice of Gene Cernan trailed off as Stetson pressed the pause on the touch screen.

  “Watching Apollo 17 again?” Jim smiled and shook his head at the same time. “God, how many times have you watched that video? A hundred times?” He reached behind Stetson and pulled forward a chair. Though good-naturedly teasing his friend, he didn’t really take his own eyes from the screen as he sat down. After all, no modern astronaut had ever made it higher than a few hundred miles above Earth. Cernan had walked on a body about two hundred and forty thousand miles away. What astronaut wouldn’t be in awe of the Apollo-era groundbreakers?