He looked around the room and let that sink in.
“We do have some things going for us,” he finally said. “We have some of the parts built for the Ares 4 presupply missions. We can steal from them, and that’ll save us some time. Also, we’re sending food, which is pretty robust. Even if there’s a reentry problem and the probe impacts at high velocity, food is still food.
“And we don’t need a precision landing. Watney can travel hundreds of kilometers if necessary. We just need to land close enough for him to reach it. This ends up being a standard tumble-land presupply. All we have to do is make it quickly. So let’s get to it.”
[08:02] JPL: We’ve spun up a project to get you food. It’s been in progress for a week or so. We can get it to you before you starve, but it’ll be tight. It’ll just be food and a radio. We can’t send an Oxygenator, Water Reclaimer, or any of that other stuff without powered descent.
[08:16] WATNEY: No complaints here! You get me the food, I’ll be a happy camper. I’ve got all Hab systems up and running again. The Water Reclaimer is working fine now that I replaced the burst hoses. As for water supply, I have 620L remaining. I started with 900L (300 to start with, 600 more from reducing hydrazine). So I lost almost 300L to sublimation. Still, with the Water Reclaimer operational again, it’s plenty.
[08:31] JPL: Good, keep us posted on any mechanical or electronic problems. By the way, the name of the probe we’re sending is “Iris”. Named after the Greek goddess who traveled the heavens with the speed of wind. She’s also the goddess of rainbows.
[08:47] WATNEY: Gay probe coming to save me. Got it.
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 to 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. A course 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
He began an email to his boss.
