Dead on Mars

Chapter 179 - Sol Three Hundred and Twenty-One, Seven Kilograms of Thrust
Tang Yue entered Kunlun Station and took off the life support system. Tomcat was wearing an earpiece hugging its hind feet as it sat on a chair. It was looking free and easy.

When Tang Yue took off the Radiant Armor, he heard Tomcat singing “God is a Girl.”

But when he listened carefully, the lyrics were different.

“God is a cat,

“Wherever you are,

“Do you believe it, can you receive it?”

It was actually singing, “God is a Cat.”

“Miss Mai Dong, take note. You are sixty-six meters from the core module. You are a little too far.” Tomcat glanced at the image on the screen as it gave a warning. “You should start heading back.”

“Mr. Cat.” Mai Dong sounded to be in a bit of a predicament. “I’ve just released the anchor cable, but I can’t reach the handle.”

“OK, don’t panic… I’ll switch on the cable hoist to pull you back,” Tomcat looked up and saw Mai Dong helplessly floating two meters from her working position. She was desperately trying to reach her hand out for a handle on the wall.

Tomcat remotely switched on the power and the safety tether on Mai Dong’s EVA suit tightened as she was pulled back towards the space station. This continued until the girl grabbed onto the maintenance handle on the space station’s outer walls again.

“Miss Mai Dong, hold tight next time.”

Mai Dong nodded and hooked the anchor rope onto the wall.

“What are you doing?” Tang Yue hung up the Radiant Armor as he walked over with a cup of water. “Another repair?”

“The Hall-effect thruster,” Tomcat replied. “It’s a 600 kW Hall-effect thruster, SPT276, that was replaced from the Hayabusa III asteroid probe during the last Mars mission.”

“Hayabusa III?” Tang Yue tried hard to recall. He had heard of that name and it was apparently something from the Japanese. In the past few decades, the Japanese have become rather enamored with making asteroid probes. Each one of them surpassed their predecessor in terms of distance traveled. “It’s an asteroid probe, so shouldn’t it be in the asteroid belt? Why is it in the space station?”

“But it won’t be in the asteroid belt forever. The Hayabusa III probe will pass by the United Space Station in its forty-fourth orbit during its mission. Therefore, the space station’s occupants will do some maintenance on it when that happens,” Tomcat explained. “But that probe’s propulsion device has malfunctioned, so it’s been dismantled and placed in there.”

“Where’s the probe?”

“It flew off,” Tomcat replied. “The probe malfunctioned and delayed the mission, so the probe’s exploration plans were abandoned. Therefore, Mission Control decided to make it a deep-space probe. It was sent out with a gravitational slingshot thanks to Jupiter. By now, it should have already gone past Jupiter’s orbit.”

“Why are you fiddling with it?”

“We’re trying to see if we can fix it,” Tomcat said. “If it can be repaired, the space station’s attitude adjustment won’t require the Orion II’s Raptor rockets. This will maximize the space station’s lifespan. Even if Miss Mai Dong lands, the space station will continue staying in orbit for a very long period of time.”

“You know how to fix that gizmo?” Tang Yue was somewhat puzzled. He pulled a chair over and sat beside Tomcat. “If I recall correctly, a stationary plasma thruster and a chemical rocket’s structure are completely different.”

Tang Yue looked at the schematic on the monitor to the left of Tomcat. The Hayabusa III asteroid probe SPT276 stabilizers and stationary plasma thruster was a cylindrical body with a diameter spanning more than a meter. It resembled a spotlight and it was installed on the space station’s truss. During the last Mars mission, the astronauts had dismantled it from the Hayabusa III and placed it there, perhaps to take it back on the next mission.

“It’s different.” Tomcat shook its head. “It’s slightly bigger. The Hayabusa III probe SPT276 is currently the biggest stationary plasma thruster in service.”

“How big is it?”

“Its thrust reaches a terrifying…” Tomcat said with utmost seriousness, “70 N!”

Seventy Newtons?

Seven kilograms?

An engine rocket with a total thrust of seven kilograms?

Tang Yue was somewhat puzzled.

“A rocket with a total thrust of seven kilograms can push a four-hundred-ton space station?”

“At most, the acceleration will be small. It will eventually move as it’s pushed,” Tomcat said. “No matter how small the force is, an electric rocket’s advantage is its high impulse!”

Mai Dong was following Tomcat’s instructions to repair the thruster. The huge item, with a diameter spanning more than a meter, brought certain conveniences to the repairs. The Hall-effect thruster’s layout was relatively simple. It was a lot easier than a chemical rocket. SPT276’s malfunction wasn’t serious; therefore, when the asteroid exploration plans were shelved, Mission Control had thrown Hayabusa III out the Solar System while keeping the thruster behind.

Mai Dong carefully dismantled the thruster’s hull.

Unlike traditional chemical rockets, SPT276’s internals didn’t have any reservoir tanks or turbopumps. Nor did it have any complicated, twisted pipes. In their place were dense electromagnetic line circuits and layers of insulation walls. Such a stationary plasma thruster used Xeon ions as its thrust and electricity as its energy source. It didn’t need large amounts of methane and oxygen.

Mai Dong felt as if she was repairing an electrical appliance, such as an induction cooker.

“With this thruster, we can at least extend the space station’s lifespan by a third.” Tomcat was pleased. “It will live for another six years. Ideally, it might even work for ten years.”

Tang Yue didn’t care about the United Space Station’s lifespan. After all, he didn’t have that long to live. Nor did Mai Dong. With him and Mai Dong dead, the uninhabited space station was no different from a tomb.

Tomcat seemed glad that it was extending the lives of every human relic, extending them from three years to six years, or six years to ten years. However, Tang Yue lacked interest in such actions. Deep down in his heart, he viewed it with numbed coldness.

Everything would fade away. Death waited at the end of every road for everyone.

“I only wish to know when Orion II can land.”

Tomcat and Mai Dong were taken aback.

“I also wish to know when Orion II can begin the landing,” Mai Dong whispered as she stopped what she was doing.

“I’ve mentioned it before. It’s estimated to be about twenty hours from now… The landing needs to have all the preparation work completed before it can begin,” Tomcat replied. “However, Miss Mai Dong, I have to remind you once again that it’s extremely dangerous for Orion II to enter the atmosphere again. The chances of failure are high. There’s actually no need for you to do it…”

Mai Dong had already lost count of the number of times Tomcat had reminded her of the risks of descending. It was quite obvious that Tomcat didn’t have confidence in a safe landing. Tomcat had gone for broke due to the comet’s threat. To rally their morale, it had said to Mai Dong and Tang Yue that there wouldn’t be any problems.

But now, Tomcat had already lost the reason to lie.

It had transformed back into the cold, rational scientific station’s assistant that measured the pros and cons of everything. From its point of view, the best choice for Mai Dong was to stay put.

“I know,” Mai Dong cut it off, “Mr. Cat.”

The girl’s voice was very soft and slow, but it was said in an irrefutable manner.

“I’m not afraid of death, but I don’t want to die in the space station,” Mai Dong said. “If I have to die… I hope to die on Mars.”