The Orbital Mechanic

The Orbital Mechanic (Complete story in one post)

Engineering Stories – Short Stories (Realistic Fiction) in Science, Technology, Engineering, and Math (STEM)

Come into my office, conference room, and laboratory – Experience my adventures, teams, challenges, thoughts, travels, and sudden insights

Kenneth Richard Hardman

Copyright © 2013 Kenneth Richard Hardman

All rights reserved. This book is a work of fiction. The characters, incidents, and dialogue are drawn from the author’s imagination. Any resemblance to specific events or persons, living or dead, is coincidental.

DEDICATION – Glenn and Dorothy Hardman – To My Father and Mother, for teaching me, no, for showing me how to work, how to play, how to smile, and how to care.



“Dad, what a cool office.” Kayla hopped into the high-back chair behind a handsome desk lined with little spacecraft models and rockets. “I didn’t know you work in a place like this.”

“Well,” Dr. Thomas Dixon said to the fourteen-year-old, “I also spend some of my time in conference rooms and laboratories.” Kayla’s father carefully lifted a small model and glided it through the air in a curved path in front of his office window. The company marquee outside read, “Welcome to Bring your Child to Work Day.”

“It seems extra bright outside.” Dr. Dixon closed the blinds.

“I’m just glad to be out of school for a day.” Kayla said.

“Now,” Tom thought, “how am I going to get her to see how exciting science is? He slid a chair right beside Kayla, tapped the space bar on his laptop keyboard, and typed a password.

“So dad, I know that you do something with spaceships, but whenever you leave papers around the house, all I see is circles and curves and numbers. Are you some kind of spacecraft artist?”

“I guess conic sections could be viewed as art,”

He thought, then turned to Kayla. “Not a traditional artist; I’d say I’m more of an architect, but I don’t design buildings.” Tom moved the mouse around, clicked a couple times, then pointed at the screen. “Look here. Do you recognize this?”

“Of course dad, it’s our solar system.”

“Right. Well, what do humans know about all these planets, and how did we get that information?”

“That’s easy, we just search for it on the internet. I did a research paper last year on Pluto. Did you know it’s not a planet any more?”

“So they say.” Tom tightened his lips. “No one on Pluto told us what Pluto is like, and there’s certainly no internet connection there, yet. What we know came from using telescopes and space probes to take pictures, and measure motion, and frequencies of light; then someone could put the information on the world-wide-web.”

“Hey, do you think we’ll ever have a solar-system-wide-web?”

“Likely!” Tom said with a smile, then patted his daughter on the back. “And maybe you’ll be the one that invents it.”

Kayla picked up one of the models on the desk. “So is that what these are, interplanetary space cameras?”

“Yes, but they do more than take pictures.”

“So your company designs spaceships. What exactly do you do?”

“I decide what path or trajectory to take to get there.”

“That doesn’t sound too hard. Just launch it on a rocket, and point it at the planet you want to go to.” Kayla turned when she heard her father laugh.

Tom clicked again and pointed. “Look here. This is called a interplanetary trajectory map. It’s an overlay, kind of a road map printed on the solar system.”

“One, two,” Kayla pointed at the circles on the screen starting from the sun moving outward. “Three. This one is Earth, right?”

“Yes. Now as you know all these planets are moving around the sun. Our planet goes around the sun in…”

“I know dad, 365 days.”

“That’s my girl. The closer the planet is to the sun, the faster it orbits around the sun. If we want to go from Earth to, say Jupiter, we can’t just aim for Jupiter, because it takes a number of months to get there, and Jupiter won’t be there any more if we just point in that direction from the start.”

Kayla squinted, then pointed at Earth’s ellipse. “Why is the spaceship path from Earth to Jupiter going around the sun?”

“Kayla, what you’re looking at is the very mission we are performing right now, in space. In fact, we are at an exciting time in our mission to Jupiter. The spacecraft is called Vector1.” Tom pointed at Earth on the map. “We launched a year ago and in three days from now Vector1 will pass by Earth on it’s way out to Jupiter. It’s been around the sun…”

“Wait. Why is Vector1 coming back to Earth if it hasn’t been to Jupiter yet?”

“It’s called a gravity assist maneuver or fly-by. To get to great distances and speeds, we swing by planets and take some of their energy.” Tom slowly moved his finger along the curve approaching Earth. “We fly in behind them and let the planets gravity accelerate the spacecraft and give it enough speed or energy to make it farther out into space, farther away from the sun. This way, we don’t have to use as much rocket fuel; fuel is heavy and very expensive to lift into space.”

Kayla wiggled in her seat and rubbed her nose. “So, you plan pathways that follow the planets, which speeds up the spacecraft to keep it going deeper into space.”

“That’s a simple view of it, but pretty much correct.”

“But if you just come in behind the planet, why doesn’t the planets gravity just pull it in and make it crash?”

“Very good question. We don’t try to hit the planet as we follow it. We point to the side a little so the planet does two things. It makes us go faster, and it turns or steers the spacecraft in the direction we want to go. The trick is approaching the planet just right.”

“Kayla squinted her eyes a little and pinched her chin.

“Here, let me make it a little easier. Picture our big round trampoline at home. Now imagine it with a bowling ball resting right in the center. Now, suppose you and I are standing on opposite sides of the tramp. To roll a soccer ball from me to you, I would roll it along the trampoline so it passes just to the side of the bowling ball. What will the soccer ball do as it rolls along?”

“It will turn toward the bowling ball because that’s downhill.”

“Right. If it rolls too slow, it will turn too much toward the center, and hit the bowling ball. If it rolls fast or far away from the ball, it will pass by the bowling ball while turning toward it just a little. If I roll it even faster, it will turn a little and then roll off the far side of the tramp. Picture every planet as a bowling ball in the center of a trampoline causing things that come near to steer toward the planet. We can use these gravity pulls to turn and steer the ship where we want it to go.”

“Cool.” Kayla picked up a different model and held it high as she flew it around a globe in the corner of the room.

“And let’s suppose the trampoline was orbiting around the house…”

Kayla raised her eyebrows. “Sorry dad, I can’t imagine a trampoline orbiting our house.”

Tom looked up for a moment. “Okay, try this. Remember when we all went skating? Suppose you and I were skating along and I was a little ahead of you. Now if I reached back and grabbed your hand, then pulled on you and swung you out in front of me, you would speed up and I would slow down a little, you would be going faster than you were before, and I would be going a little slower. That’s what the planet does to the spacecraft.”

Kayla closed her eyes half way. “It sounds like a lot of math.”

“Yes, and physics and other important school subjects. But it’s really powerful to know how to…”

“Dr. Dixon!” A man in his early twenties with a red face, out of breath, stood in the doorway of Tom’s office.

“Hi Ben, how is your internship going?”

“I’ll tell you about that later. We have a serious problem and I came to get you.”

“What are you talking about?”

“There’s been a solar flare, larger than expected. As programmed, Vector1 computer systems automatically shut down for radiation protection.”

Tom stood and moved quickly toward the window and parted the blinds.

Ben continued. “They’re not sure if the solar panels retracted in time, the radio signal has gone quiet. Anyway, the solar wind gave us a nudge, and they say she’s approaching Earth high and wide.”

“No!” Tom turned from the window, distinct wrinkles across his forehead. “This can’t be. Everything was going well. We’ve worked so hard for this.”

Ben opened the door wide. “The director wants the best orbital mechanic, in the control room, right now” Ben pointed at Tom and raised both eyebrows. “That means you.”

Tom grabbed his laptop and headed for the door. “Kayla, come with me. It looks like ‘Bring Your Child to Work Day’ is not going to be routine.” Tom pointed at the spacecraft Kayla was flying around the office. “Bring that model.”

Kayla lowered the spacecraft and followed the two men quickly down a long hall.

“What happened Ben? We’ve experienced solar flares before. Why is she off course? Why do you think the solar panels are still extended?”

“That’s the only explanation for the change in trajectory. And there’s another problem; we don’t know the spacecraft attitude…”

“A spacecraft with an attitude?” Kayla thought out loud, but the two men did not hear her. “Well if I had just been hit by solar wind, my attitude would be bad.”

Tom and Ben entered the control room, with Kayla gravitating right behind. Her father pointed to a chair in the corner. “Ben, would you sit by my daughter? She’ll probably have questions and I’ll be too…”

“You got it Dr. TD.” Ben replied.

“Dr. Dixon, the timing couldn’t have been worse.” A man with a dress shirt and loose tie sighed a small measure of relief when Tom entered the room. He pointed at a computer monitor. “From all we can tell, the solar wind had enough effect on Vector1 to put our periapsis or perigee burn altitude too high.”

“Kayla.” Ben leaned over and spoke quietly. “Ask me anything you want.”

“Why did you call my dad an orbital mechanic? That sounds like someone with wrenches on the space station that goes around fixing broken satellites.”

Ben grinned. “An orbital mechanic uses math and physics to predict how planets, asteroids, and spacecraft react to the gravitational pull of each other.”

“Oh. So that’s how he can plan trips to Jupiter.”

Tom leaned over and examined the screen. We’re off by a few arc-seconds.

“We’re on the wrong approach trajectory to Earth. We need a course correction burn immediately,” Tom pronounced with a very serious tone, “or we’ll be on the wrong departure trajectory leaving Earth; we’ll be headed no-where at high speed.”

“We can’t maneuver within an hour,” Another man, plaid shirt and blue jeans yelled from across the room.  “Vector1 is in radiation shutdown for fifty-five more minutes. And when she comes back on line, if she comes back on line, we don’t even know her attitude, we could make things worse with a hasty burn. We could come in low and have aerodynamic drag in the Earth’s atmosphere…”

Kayla looked at Ben.

Ben whispered. “A burn means to fire the on-board rockets to change it’s direction or speed. It’s often called a Delta-V or Delta-velocity.”

“What are you talking about?” Dr. TD raised his voice.

“Tom, it’s very possible that the solar panels were damaged by the flare. They weren’t designed to take this much radiation. They were supposed to retract temporarily for events like this.”

“I know all that. Are you telling me that our billion dollar mission is gonna fail because…”

“Okay, hold on everyone.” The mission director demanded everyone’s attention, then walked over to the whiteboard. He drew a small circle in the center surrounded by three slightly oval or elliptical circles, progressively larger representing the orbits of the planets out to Jupiter. He drew the flight path of Vector1 starting from where the Earth was a year ago for launch, around the sun just past Venus, and approaching Earth’s present position. He drew an X representing the position of Vector1, very close to Earth, then a dashed arc passing just outside Earth and on out to Jupiter.

“Why didn’t he draw Mercury or Mars?” Kayla whispered.

“I’ll tell ya’ in a minute.”

The director continued, “In three days, Vector1 will make it’s closest approach to Earth.”

“That’s called perigee” Ben said to Kayla.

“On it’s current path her altitude will be too high.” The director handed the marker to Tom. “What are our options? Let’s get them all on the board.”

“Wow, dads pretty important. He’s got to figure out how to save this mission.”

“Sometimes they call him Dr. TD for Touchdown when the probe hits the target. Or sometimes it’s Dr. T for ‘trajectory’ because he’s the best trajectory planner on the planet.”

“Okay.” Tom accepted the pen and moved to the board. “Is there anyway to command power-up any sooner than fifty-five minutes?”

Several head movements indicated no.

“Jerry, do we still have our full budget of extra fuel?”

“Yes, all prior burns have been planned, nominal, and within budget.”

“If we could burn now, we could correct it with one burn, perhaps even in an hour.” Tom drew a red curve from the X passing between Earth and the present trajectory.

“Remember Tom,” a lady at one of the computers said, “once the computer powers up, it will take another thirty minutes for it to perform system checks and to confirm attitude. We can’t burn until that’s done.”

“But you’re not sure we have an attitude problem, right?” Tom asserted.

“That’s true. If we knew the attitude was okay, we could burn right after she wakes up.”

“Can you give me a probability? What are the odds that Vector1 is still at the right roll, pitch and yaw?

There was silence for ten seconds.

Ben held his hand out flat, palm down, in front of Kayla. “This is roll.” Ben rotated his hand thumb down, then thumb up. “This is pitch.” Ben pointed his finger tips downward, then upward. “This is yaw.” He rotated his hand moving his finger tips left and right, keeping his palm pointed down.

Another man spoke up. “I’d say if both solar panels are still extended, then the solar wind would have acted equally about her CG”

“CG?” Kayla asked Ben.

“Center of Gravity. Kind of like the pivot point on a playground teeter-totter. If you push on both sides equally, then it won’t rotate.”

“Look.” Tom used the blue pen and sketched another curve. “We can correct this problem using two Delta-V burns a couple hours from now, but we’ll use most of our spare fuel. There won’t be any margin for error later in the mission.”

“That’s not acceptable.” The director patted a handkerchief on his forehead.

“We may be able to do it with one simple burn if we do it in one hour when Vector1 wakes up. Is there any other way to ascertain her orientation?”

Again silence.

Kayla still held the model of Vector1 in her lap, running her fingers over the solar panels. She turned to Ben and whispered. “I remember a time when dad and I were out on the back patio of our house an hour after sunset looking for shooting stars. Dad pointed out a satellite passing slowly overhead reflecting sunlight from it’s solar…” Kayla stopped and looked over toward her dad then mumbled. “Why don’t they just look at it through a telescope.”

Kayla grabbed Ben’s arm. “Why don’t they just look at Vector1 through a telescope? Or a few telescopes?”

“I don’t know. I haven’t been here long enough to know if that will work. Usually space probes are too far away for a visual. But this one’s close to Earth.”

“Uh, Dr. Dixon.” Ben raised his hand slowly. “Sir, I don’t know if this is practical, but Kayla has a suggestion.”

The director turned to Tom. “Who is this Tom?”

“This is my daughter, Kayla. She’s here for…”

“This isn’t a good time for a field trip.” the director said.

“I know sir,” Ben insisted, “but I think you may want to hear what she has to say.”

“Okay young lady, if you’re as smart as your dad, we need to hear it.”

All eyes turned on Kayla.

“Well, my dad showed me a satellite one night flying overhead. The solar panels reflect the sun just after sunset if they’re pointed in just the right way. If Vector1 is close enough to the Earth, can’t we look through telescopes and see how much the solar panels are reflecting?”

Several people in the room suddenly turned back to their computers and began typing.

“Ya, remember that time,” someone in the room said, “that we needed to determine the condition of the Space Shuttle. We pointed lasers and telescopes from Patrick Air Force Base and they were able to see into the shuttle bay and…”

The room turned from silence to business. “Get on it people. Contact all the space surveillance sites and get those telescopes pointed at Vector1.”

Dr. Tom looked over at his daughter and gave her a wink. The director nudged Tom’s arm with his elbow.

Within fifteen minutes, the tracking stations began reporting.

“Affirmative!” The man in the plaid shirt called out. “Indeed, Vector1 solar panels appear fully extended and her attitude unchanged by the solar flare.”

Dr. TD began running simulations on his laptop to plan for the correct Delta-V needed right when Vector1 came online.

Kayla and Ben were no longer sitting in the corner. Now an integral part of the team, they looked over shoulders at data on various controller screens. Optimistic tension still filled the room. Tom uploaded the burn parameters into the main flight computer.

“She’s awake.” yelled one of the controllers. “Vector1 is back on line.”

“Are you ready!” the Director said to Tom.

“We are ‘go’ for Delta-V burn.” Tom replied.


Immediately, the command was issued. Within seconds, favorable telemetry signals were received. Within minutes it was confirmed; Vector1 made the course correction successfully. The control room erupted with cheers. Kayla joined the high-five ceremony.

The good news, Vector1 could continue on her journey to Jupiter; the bad news, there was a good chance her solar panels were damaged in the flare. This would reduce mission capability, but not crush it.

Ben elbowed the ninth-grader. “I think they should rename it, Kayla-one.”

Mentor Discussion and Exercises

  1. Would you like to be the engineer, mathematician, or scientist that figures out how to get spaceships to distant worlds?

If so, you may want to consider a career in Orbital Mechanics, also known as Celestial Mechanics, or Astrodynamics. It’s a great job. Engineers of this type must understand the laws of physics, mathematics, and computers. Dr. Dixon used all these tools to plan and simulate interplanetary trajectories. As a result, mankind gets more experience with space, and the truth about distant places.

  1. What did you learn from this story?
  2. Why does it take so long to get to Jupiter or other planets?
  3. Is there a way we can get there faster?
  4. Why did Dr. Dixon send Vector1 around the sun, past Venus, and back to Earth before going to Jupiter?
  5. Why did the solar flare knock Vector1 off course?
  6. Could solar wind make that much difference?
  7. Why was Kayla able to think of a solution when others didn’t?

Everything we see and experience in our lives might help us solve a problem someday. Even in school, all of our classes give us knowledge and perspective to help us be more creative and aware. Next time you’re in a math or science class, listen for terms like parabola, conic sections, or Newtons laws of motion. With tools like these, you could be The Orbital Mechanic that takes mankind to new and very distant places.


In Get a Grip, a young engineer is astonished to be assigned to an experienced team responsible for developing critical automation in the manufacture of smart phones. She travels with the team on a foreign customer visit, participates in creative concept generation, and helps the team through difficult setbacks and technical problems.

In The Orbital Mechanic, a solar flare knocks a space probe off course endangering a costly mission. A simple  solution comes just in time from an unlikely source to save the spacecraft. In this story, learn how engineers use science, math and physics to get spaceships from Earth out to distant planets and beyond.

In Foot Notes, an engineer is faced with the daunting task of inventing a cost effective foot scanner in a short amount of time, driven to search for and consider possible solutions, taking clues from the near and far, the past and present, the people and objects all around. After much effort, old impractical perceptions are pushed aside by new achievable techniques.

In Quick Step, an engineering team is required to create a way to make customer arch supports (orthotics) in 30 minutes. They face hurdle after hurdle as they try to find an answer to a fundamental friction problem. In the end, after much frustration, determination and creativity, they stumble onto a completely different yet very elegant approach.

In Cutting Edge, a student engineering team wins a bid to develop an automated synthetic diamond cleaning (blasting) machine. They familiarize and immerse themselves in customer needs, write specifications, research similar equipment, brainstorm solutions and evaluate their options. They experience the pain of unforeseen problems and the thrill of success looking externally and internally to find answers to complex questions.

In Speed Reader, two engineers have been working hard for weeks to prepare for and demonstrate the capability of their design. On the Friday of their last week of testing, the customer is not fully satisfied, launching the engineers into a last minute creative mode to find a quick and reliable solution, and to save their weekend plans.

In The Ribbon Cutting, three engineers work to create a complex system, a cutting machine with a blade that automatically morphs into shapes needed for unique products. Ideas and solutions are found all around them, in their hobbies, in other machines, in books and online. Their specific talents unite as they help each other move their company forward.

Use the following search phrase online to find additional Engineering Stories.

“Hardman” AND “Engineering Stories”

Engineering Stories are available online and in paperback. Contact the author for paperback information and volume purchases.


Ken Hardman graduated from Brigham Young University with a Master of Science degree in Mechanical Engineering. He is an Associate Technical Fellow at a major aerospace company, and a Licensed Professional Engineer. As of this writing, he has worked nearly 30 years in the aerospace and industrial automation fields defining, creating, researching, evaluating, managing, testing, and supporting satellites, aircraft, test equipment, and industrial automation. As an Adjunct Faculty, Ken has mentored and coached engineering students for many of those years. He loves to solve design problems, create useful solutions and encourage others to do the same.

About Kenneth Richard Hardman

AncestorClips are very short stories about very real people. Each clip nurtures awareness of a time, a place, and the character of a man or woman who cultivated a path for our life. The reader feels the good, the obstacles, the happiness, the sadness, and the overcoming. They cheer us, make us resilient when challenged, give us purpose, and connect us to our multi-generational family. Each story is followed by reflections from the author and readers sharing how the story strengthened or inspired them. Ken Hardman is a son, a brother, a grandson, a great-grandson… He is also a husband, father and grand-father. Ken is a professional engineer, engineering mentor, technical writer, and associate technical fellow at a major aerospace company. He is a writer of engineering and family history stories. Please join Ken in reading, reflecting upon, or writing #AncestorClips
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