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The Maretian

by Kris Overstreet

Chapter 206: Sol 370

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They gathered in Teddy’s office: the usual group of Teddy, Venkat, Mitch, Annie, and (via teleconference) Bruce, plus Mindy Park from SatCom.

“So,” Teddy said, once Bruce’s call was connected, “how are the Hab crew coming on the booster test?”

“Ready to go on their end,” Venkat said. “Mark completed the procedure we sent him to remove the short-range transmitter on the northern weather station and rewire it to boost its signal. Once he connects power, it’ll transmit for two hours on the battery it has. The transmitter itself will probably melt in less than half an hour. But for as long as it lasts, the signal strength should be good enough for any orbiter on that side of the planet to pick it up.”

“Um, yes,” Mindy Park continued. She was the only person in the room not in a neat suit, and her bloodshot eyes made it obvious she didn’t care what the higher-ups thought of her old Astrocon T-shirt and sweat pants. “On Sol 374 six of our Mars satellites will be in position to track the launch. I finished testing software updates that will let them track the signal and send that data to us. As soon as Dr. Kapoor gives me authorization, I’ll upload the software patches and then go home and go to sleep.”

“Our target time is two hours before sunset,” Venkat continued. “It’s a compromise between the optimal trajectory for a perfect sun intercept and the restrictions of communications. Hermes and Earth both drop below the Hab’s horizon about thirty minutes before sunset. As nice as it would be to have one less piece of space junk to deal with, the important part of the test is to verify the numbers the ponies got when this system was tested on their homeworld.”

“Yes, about that,” Teddy said, picking up a piece of paper. “Did I read this correctly? Six G's of acceleration from the launchpad, rising to a peak of eight and a half G’s after three minutes? For a vehicle that weighed twenty tons, fuel and capsule, at launch?”

“So Starlight Glimmer reported, yes,” Venkat said. “And to be clear, their best estimate is that their world and Earth have the same diameter and gross mineral composition, so their one G is the same as ours. Also, they didn’t get a solid rate of decay for the booster’s effectiveness over distance. Their flight was an orbital launch, and the ship went over the horizon while the boosters were still about eighty percent effective. Again, their estimates.”

“I understand the caveat,” Teddy said. “Now tell me what it means for this launch. One G is nine point eight meters per second squared of acceleration, on Earth, right? So how fast is the test vehicle going to go?”

“Well, there are a lot of differences,” Venkat said. “For one thing, after their last test the ponies decided to restrict the power flow to the boosters, both to lengthen the life of the batteries and to prevent the MAV passengers from being crushed. And for this test, instead of using the fifteen large batteries, they’re only using nine normal batteries. They predict a net force reduction in the booster system of about sixty percent for the test.

“But the final test vehicle, according to Mark’s measurements, has a mass of 1.62 tons.” Venkat smirked as he added, “One point six two is a bit less than twenty. So even with only forty percent of the force on the target vehicle, the test vehicle’s going to move a lot faster. If the pony test is accurate, we’re estimating a launch acceleration of just under thirty G’s.”

Mitch lurched up from the couch. Mindy came wide awake. Teddy whistled.

“In English, please?” Annie said.

“A sudden and momentary acceleration of thirty G’s causes severe injury in humans,” Venkat said. “Sustained, it’s lethal in seconds.”

“Put it another way,” Mitch said, “that rocket engine will be going faster than a civil war cannonball almost the instant it leaves its pad.”

“Within about two seconds,” Bruce chipped in over the teleconference. “According to Starlight, they expect their battery array to power the system for about seventy seconds. Assuming ideal conditions- a straight vertical trajectory with no divergence due to air resistance- at the end of seventy seconds the target would be going twenty kilometers per second relative to Mars, at an altitude of not quite seven hundred kilometers.”

“Twenty kilometers per second,” Teddy said quietly.

“That’s right,” Venkat said. “Our friend at astrodynamics said that doesn’t quite get us a direct shot into the sun, but the resulting solar orbit will pass close enough to the sun to turn it into a fairly short-lived comet.”

“Twenty kilometers per second,” Teddy said again. “No fuel. No engine on the craft. Twenty kilometers per second. In just over a minute.” He took a deep breath. “Have we asked the ponies why they haven’t used this system before?”

“No, but I can think of several drawbacks from the start,” Venkat said. “First, they can’t steer the thrust. It just pushes its target away from itself. Second, once they’re out of range of the booster, their ship still needs its own engines for steering, orbital adjustments, and the like. Finally, the system requires a planetary mass to rest on, or else you run into serious issues with Newton’s Third Law. Try to make one ship push another, and you end up with two vessels getting accelerated apart on varying trajectories.”

“Most likely they just never thought of it,” Annie said.

Every eye turned to the press director.

“Oh, come on, you fucking geniuses didn’t think of that?” she asked. “Look at it. They live in a world so lousy with magic that they barely developed magic batteries until they invented an engine that used magic faster than it could be drawn out of the fucking air. They didn’t think, ‘we can’t lift this thing, go get more batteries.’ They thought, 'We can’t lift this with magic, so let’s fart around with a bunch of dangerous explosives and radical new ideas like electronics and radio and shit and see if that works.'

“But then some of them got dropped into our world, where magic is like rainfall in Yuma. And they didn’t have any rocket fuel, or electronics, or any of the newfangled shit they were just getting used to, but they got lucky and found enough crystals for a New Age hippie wet dream. So then they thought, ‘We don’t have rockets, but maybe we can use magic.’ And so they stumbled across the fucking holy grail of space exploration- cheap, reusable surface to orbit launch- by complete fucking accident.”

“How do you create a launch system by accident?” Mitch asked.

“Oh, for fuck’s sake,” Annie grumbled. “Read your own goddamn history. I have to know ten zillion cutesy little anecdotes about the early manned space program so I can sprinkle them into my bullshit sessions with the press. More than half your major advances in rocket and capsule design almost didn’t happen. We were originally going to the moon in a single fifty meter tall tail-lander with an enormous ladder until what’s-his-name, Houbolt, jumped over three layers of management to push lunar orbit rendezvous as a fuel-saving mechanism. Because Wehrner von Braun assumed you couldn’t rendezvous ships in lunar orbit. Think of how many damn things seem so obvious now, that weren’t obvious when our grandparents got all this shit started!”

“Assumptions,” Teddy said, nodding. “Thank you, Annie. I think a re-read of some of the books on my shelf is in order.” He swiveled in his chair to look at the television screen. “Bruce, what does this mean in practical terms for the MAV?”

“The MAV weighs about twenty-eight tons fully fueled- that’s the two ascent stages and the capsule,” Bruce said. “With the reduction in force, the boosters will provide an extra three G’s at launch, in round numbers- twenty-eight meters per second. A little more than a minute of that would be enough, by itself, to make up the difference between Mars orbit and the velocity required for the Hermes intercept- without a single modification.”

“Well!” Mitch flopped backwards onto the couch. “I call that a win! Why not hold the crew back at the Hab a couple more weeks, then?”

“We’re still going to lighten the hell out of the MAV,” Bruce continued. “The goal is to get onto trajectory with the second ascent stage unignited. That stage can be relit several times, so we can use it for any fine-tuning required to reach Hermes. And even if this test goes perfectly, we can’t put perfect faith in this system. After all, the Sparkle Drive had two successful flights before the one that landed our guests in Mark Watney’s lap.”

Everyone sobered in the face of this obvious truth.

“But the good news is,” Venkat added, “we don’t need to use the rebuilt Sparkle Drive for the ascent.”

“That is good news,” Teddy said. “But I want everyone to consider this. If we could duplicate this launch system, and create our own Sparkle Drive, the entire solar system is at our fingertips. If the cave farm can generate enough magic to launch the MAV almost by itself-“

“It could, almost,” Bruce agreed. “With steering thrusters, at least. We’d have to choke down more on the velocity to spare the astronauts in the future.”

“Then think how much power is generated every second by all the wild plants and animals around the Cape,” Teddy continued. “We could launch entire space stations at once- no, entire starships. This technology, or magic, will revolutionize space flight. I cannot stress how vital it is now that we rescue the aliens, establish formal relations with their universe, and learn how to duplicate these systems.” He looked around the room and said, “I know you’re already doing everything you can for Mark and his friends, but bear in mind the sheer potential they represent. Four years from now we could be going back to Mars, not for another thirty-day mission, but to stay.”

No one could say anything to follow that except, of course, goodbye.

Author's Notes:

Yeah. I sat down and did some quick and dirty math. I don't know how to do integrals anymore, if I ever learned, so I made estimates and used a spreadsheet...

... and yeah, the booster system Starlight thought up and Twilight implemented is, well, even more impressive than I thought.

And I'm sure absolutely NOTHING will go wrong with it.

Today's chapter inspired by comments, of course.

Tomorrow's chapter will be the launch.

And, finally, thanks to those who chipped in on the shirt Kickstarter! If you pledged, please check for your survey and answer, so I can make some decisions on production.

Next Chapter: Sol 374 Estimated time remaining: 8 Hours, 56 Minutes
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