Kari Lippert

“Rich Purnell sipped coffee in the silent building. Only his cubicle illuminated the otherwise dark room. Continuing with his computations, he ran a final test on the software he'd written. It passed.

With a relieved sigh, he sank back in his chair. Checking the clock on his computer, he shook his head. 3:42am.

Being an astrodynamicist, Rich rarely had to work late. His job was the find the exact orbits and course corrections needed for any given mission. Usually, it was one of the first parts of a project; all the other steps being based on the orbit.

But this time, things were reversed. Iris needed an orbital path, and nobody knew when it would launch. A non-Hoffman Mars-transfer isn't challenging, but it does require the exact locations of Earth and Mars.

Planets move as time goes by. An orbit calculated for a specific launch date will work only for that date. Even a single day's difference would result in missing Mars entirely.

So Rich had to calculate many orbits. He had a range of 25 days during which Iris might launch. He calculated one orbital path for each.

He began an email to his boss.

"Mike", he typed, "Attached are the orbital paths for Iris, in 1-day increments. We should start peer-review and vetting so they can be officially accepted. And you were right, I was here almost all night.

It wasn't that bad. Nowhere near the pain of calculating orbits for Hermes. I know you get bored when I go in to the math, so I'll summarize: The small, constant thrust of Hermes's ion drives is much harder to deal with than the large point-thrusts of presupply probes.

All 25 of the orbits take 349 days, and vary only slightly in thrust duration and angle. The fuel requirement is nearly identical for the orbits and is well within the capacity of EagleEye's booster.

It's too bad. Earth and Mars are really badly positioned. Heck, it's almost easier to-"

He stopped typing.

Furrowing his brow, he stared in to the distance.

"Hmm." he said.

Grabbing his coffee cup, he went to the break room for a refill.

...

"Rich", said Mike.

Rich Purnell concentrated on his computer screen. His cubicle was a landfill of printouts, charts, and reference books. Empty coffee cups rested on every surface; take-out packaging littered the ground.

"Rich", Mike said, more forcefully.

Rich looked up. "Yeah?"

"What the hell are you doing?"

"Just a little side project. Something I wanted to check up on."

"Well... that's fine, I guess", Mike said, "but you need to do your assigned work first. I asked for those satellite adjustments two weeks ago and you still haven't done them."

"I need some supercomputer time." Rich said.

"You need supercomputer time to calculate routine satellite adjustments?"

"No, it's for this other thing I'm working on", Rich said.

"Rich, seriously. You have to do your job."

Rich thought for a moment. "Would now be a good time for a vacation?" He asked.

Mike sighed. "You know what, Rich? I think now would be an ideal time for you to take a vacation."

"Great!" Rich smiled. "I'll start right now."

"Sure", Mike said. "Go on home. Get some rest."

"Oh, I'm not going home", said Rich, returning to his calculations.

Mike rubbed his eyes. "Ok, whatever. About those satellite orbits...?"

"I'm on vacation", Rich said without looking up.

Mike shrugged and walked away.”
― Andy Weir, _The Martian_