Newton to the Rescue

Author : Patricia Stewart, Staff Writer

“So, Sergei,” asked mission specialist Clark Zander, “How’s it look?”

“Not good, Clark,” replied Tsiolkovsky as he removed his helmet. “The meteorite punctured the aux tank. I was able to shut off the transfer valve, but we lost 60% of the fuel in the main tank.”

“Can we still take off?”

“We have enough fuel to escape Mercury’s gravity, but not the sun’s. We can’t reach Earth on our own; they’re going to have to come pick us up. Let’s call Houston.”

***
Zander and Tsiolkovsky contacted Houston and explained the situation. Unfortunately, a rescue ship couldn’t reach them for six months, and they only had enough oxygen for four. Both men somberly considered the most obvious solution, that there was enough oxygen for one of them to live eight months, but neither man was willing to suggest that option aloud. Finally, Zander broke the ice, “Look Sergei, there must be a way for both of us to get out of this alive. Can’t we stretch our supplies somehow?”

“We could probably ration the food and water, but not the oxygen. No, Clark, our only hope is to get off this rock, and meet them halfway.”

“I’m game. Any ideas?”

“Yeah, a matter of fact, I do have one. It’s a little hair brained, but it just might work.”

“I may regret this, but let’s hear it.”

“You know those UV foil blankets keeping the neutrino receivers from overheating; there are hundreds of square miles on them. I was thinking that we could sacrifice a square mile’s worth to construct a solar sail. Once we get into space, we can deploy the sail and let the solar wind blow us toward Earth.”

“How do you plan to build the support structure? We don’t have tubing to construct a framework. How can you prevent the sail from collapsing?”

“Simple, we rotate the sail like it was pizza dough. It’ll flatten out under its own CF. Then all we have to do is synchronize the ship with its rate of spin so we don’t foul the rigging. It won’t be easy, but I think we can pull it off.”

“Sure, what the hell. It beats my plan of clubbing you on the back of the head when you fell asleep,” replied Zander with a broad smile.

***
Two weeks later, the return module lifted off from Mercury’s surface. Once clear of Mercury’s shadow, they fired their port control jets and began to spin the ship like a top. When they hit 72 RPM, they released the carefully folded sail. As the sail began to unfurl, conservation of angular momentum caused its rate of rotation to decrease. The ship began firing their starboard jets to match the sail’s slowing rotation. It was touch and go a few times, but the sail eventually spread out like a giant parachute, rotating at a modest 0.6 revolutions per minute.

Zander monitored the telemetry data. “Well, I’ll be damned,” he announced, “The sail is generating twenty pounds of pull. Our acceleration is one quarter of a milligee. I think it’s gonna work.”

Under the full force of the bloated sun, the improvised solar sailing ship moved outward. In the interplanetary yachting world, the maneuver was known as “running before the solar wind”. After a minute, they had moved a modest five meters. After an hour, they had covered eighteen kilometers. After a day, they were 10,000 kilometers closer to rescue, and still accelerating.