Die on Mars - Chapter 198

c198 Day 322 (8) Stare at the sun

“The coordinate system is established.”

“The attitude-orbit coupling model is established.”

“The origin O is the target center of mass, the X-axis coincides with the central axis of the core module, the Y-axis is perpendicular to the longitudinal symmetry plane of the core module, the Z-axis is perpendicular to the Y-axis, and the three axes are right-handed and orthogonal… The inclination angle of the central axis of the space station is 14 degrees 25 minutes 37 Second.”

“The attitude control model is established!”

“The obstacle avoidance model is established.”

Both Lao Mao and Tang Yue were cautious. It was not easy to use the SPT276 ion rocket to stabilize the attitude of the space station. This engine was once installed on the Falcon III asteroid probe and was used for long-distance orbit changes. It is not The original attitude control system on the space station and even the control data link were added later. The three-axis stabilization of the joint space station itself was declared scrapped in the impact.

“The United Space Station has angular velocities on both the X-axis and the Z-axis.” Tang Yue said that according to the data transmitted from the space station system computer, the space station is not simply spinning. It is rolling and turning somersaults.

“I’ve seen it.” Lao Mao stared at the slowly rotating space station model on the monitor. “The degree of freedom of the SPT276 engine is very limited. The velocity vector on the X-axis plane can be solved, but the speed vector on the Z-axis plane is more troublesome… Mai Miss Dong, can you hear me? Miss Maidong?”

“Mr. Cat, I can hear you.”

“Listen to me, can you see the sun now?” the old cat asked.

“able.”

“Okay.” Old Mao’s face was as deep as water. “The sensors on the space station are basically scrapped. We have to find a reliable benchmark. The best benchmark is the sun. We need to orient towards the sun.”

“Ophiopogon japonicus, keep your eyes on the sun.” Tang Yue continued, “The sun, the porthole, and your eyes are three points and one line. This line is the baseline… Do you understand? Ophiopogon japonicus, you must keep your eyes on the sun.”

Maidong raised her head, and the bright sunlight fell into her eyes through the glass porthole, and soon passed through the window. The star was more than 220 million kilometers away, and it took the photons thirteen minutes to cross it. Over a long distance, they draw the straightest line in the universe in the void – if the influence of gravity is not taken into account, light propagates strictly in straight lines, and no matter how precise a ruler or compass is, it is impossible to draw such a line.

Photons drew a baseline for them.

Just keep your eyes on the sun.

“Next we will shut down most functions of the space station system computer and allocate power to the SPT276 ion engine.” Lao Mao sat on the side and began to adjust the power distribution of the space station.

The SPT276 ion thruster is the most powerful electric rocket, but it is also an electric rocket. After it is turned on, the power consumption is astonishing. Its performance on the Falcon III truly explained what is meant by “charging for five hours and turning on for two minutes.” “Because the working duration is too short, the advantages of the Hall thruster are actually not shown – but this is a JAXA product after all, and the Japanese always have strange ideas in aerospace.

The battery capacity of the Joint Space Station far exceeds that of the Falcon III asteroid probe, but it cannot withstand the roar of this thing.

As soon as Lao Mao finished speaking, all the LED lights on Ophiopogon japonicus’ head went out. Lao Mao remotely shut down the computers in the space station and transferred all power to the engines, leaving only the communication system still working.

“Miss Maidong, test the communication system.”

“Communication is normal.”

“Its thrust is only seven kilograms.” Tang Yue leaned down, “How long will it take for us to control the space station?”

“Although the thrust force is only seven kilograms, fortunately our moment arm is long enough, because SPT276 is installed on the truss. Although the thrust force is a bit small, as long as the moment arm is long enough, there is no need to worry about the moment. In addition… I guess now The total mass of the joint space station is less than one hundred tons.”

Laomao is connecting the battery to the supercapacitor. SPT276 is a 600-kilowatt giant ion thruster. The energy density it instantly releases is much higher than the battery pack of the space station. Therefore, the SPT276 engine must be stored before starting.

Responsible for storing energy is a set of capacitors, which are called supercapacitors. This capacitor is actually the fat and bulky head of SPT276. It is very sensitive and can control the engine precisely in milliseconds.

“After the supercapacitor is charged, the remaining power of the main battery pack is 2%, and the remaining power of the secondary battery pack is 33%.”

The two battery packs in the core module of the Joint Space Station are all solid-state lithium polymer batteries with an energy density of more than 400 watt hours per kilogram.

“How long can a discharge last?”

“The total operating time of the engine is five minutes. Under the pulse operating state, the actual deceleration time is forty minutes.” Lao Mao replied, “We should be able to reduce the angular speed of the space station’s spin to seven degrees per second.”

“Then what?”

“Then wait for the next charge.” Old Mao glanced at the time. “The next charge should be completed six hours later before the second posture adjustment can begin.”

“Are you going to have to wait another six hours?”

At this critical moment when fate can be decided in just one second, Ophiopogon japonicus hangs on a thread of life and death in orbit, but rescue on the ground is as slow as a turtle crawling.

“Because the solar panels are gone.” Old Cat said, “After all, we only have four sail panels left now – everyone pay attention! SPT276 is ready to start!”

Lao Mao turned on the Hall thruster on the truss, xenon ions accelerated in the electric field, and the high-speed plasma jet began to do work for the space station, but Ophiopogon felt nothing. The core cabin was still rotating, and occasionally there was a dull clanking sound. It was fragments of the space station that hit the Crystal capsule. The thrust of the electric rocket was really weak. Coupled with Lao Mao’s precise control, the entire deceleration process lasted more than forty minutes.

After the power was cut off, the Crystal cabin was just an empty shell. Maidong looked out the window and saw the fragment closest to her was suspended a few meters away. It might be the shell of a certain cabin section, about the size of a thermos bottle cap. It is large and slightly curved, with one side made of white skin and the other side made of silver metal. It is slowly turning over, reflecting the sunlight moment by moment.

Ophiopogon japonicus was very thirsty, but she did not dare to drink water.

There are now only three liters of fresh water left in the core cabin, all of which are stored in the water bag of the spacesuit. The girl does not know how long she will have to rely on this meager amount of water. She has lost the OGS cabinet and cannot use oxygen or fresh water. Cycled.

From now on, water and oxygen are non-renewable resources.

There was another slight muffled sound, a “boom”.

Apparently another fragment of something hit the core cabin. Fortunately, the relative speed between them was not very fast.

“Is there anything I can do?” Maidong asked, “except stare at the sun.”

“Girl, just protect yourself, we will solve the other problems…”

The old cat suddenly interrupted Tang Yue, “Miss Maidong, if you are willing, please sing a song.”

Sing?

Tang Yue and Maidong were both stunned. The latter was stunned for a few seconds and then smiled.

“Okay, what to sing?”

“Just sing…” Old Cat stared at the space station on the monitor, “‘God Is a Cat’.”