I live in the Martian wilderness!

Option 2: Mars high-altitude signal relay

Principle: Modify the Tianxun Mars rover, remove its core scientific instruments, and install a small signal transmitter consisting of spare electronic components and a combat suit battery pack.

The modified rover will then be driven up Olympus Mons, the highest point on Mars, or launched at maximum speed using a natural steep slope, serving as a temporary, parabolic "high-altitude signal platform".

Launch when it reaches the highest point of its trajectory to minimize signal attenuation in the Martian atmosphere.

Estimated success rate: 0.04%

Huge sacrifice: This means the complete loss of the only long-range exploration vehicle, Sky Survey.

The technical risks are extremely high: the modification of the signal transmitter and the calculation of the transmission trajectory are full of uncertainties.

The communication window is extremely short: it may only be a few seconds long, just enough to send a very simple encoded signal that "I am still alive".

Gu Yu stared at the two seemingly hopeful but actually impossible plans on the screen and fell silent.

Suddenly, he abruptly raised his head, his gaze fixed on the folded disc-shaped object on top of the Candle Dragon One through the porthole.

"Wait, no... the Candle Dragon One is equipped with a high-gain parabolic antenna! It even has a laser communication module! I used it to make a video call to Earth yesterday."

Gu Yu's voice carried a hint of urgency: "Even if the relay satellite is lost, can't we just use the spaceship's main antenna to directly transmit the signal to Earth?"

"I'm sorry, Captain. The laws of physics are cruel." Xuanjian's voice immediately shattered his illusions, and a cruel [signal attenuation curve] was projected onto the screen.

"You've overlooked the most crucial variable—distance."

"The communication system of Zhulong-1 was designed based on the special conditions that Mars is only 1 million kilometers away from Earth after the celestial changes. At this distance, it can indeed achieve broadband transmission."

"But now, we are 60 million kilometers away from Earth. That's a 6000-fold increase in distance."

Xuanjian highlighted the end of the parabola: "According to the inverse square law of radio signals, as the distance increases by 60 times, the signal strength will decrease to 1/3600th of its original value."

"With the current power of the Candle Dragon 1 transmitter, when the signal travels across 60 million kilometers of deep space to reach Earth, its strength will drop to below -180dBm."

"This means that our calls will be completely drowned out by the noise of the cosmic microwave background radiation."

"To Earth's Deep Space Network (DSN), we are currently like a mosquito trying to get attention in a storm with a buzzing sound..."

Xuanjian concluded: "Unless the transmission power is increased by a thousand times, i.e., Option 1, a valid physical-level connection cannot be established."

The light in Gu Yu's eyes dimmed. He understood that he was facing not only distance, but also an insurmountable physical barrier.

Based on his current resources, the possibility of establishing effective communication with Earth in the short term is infinitely close to zero.

Gu Yu put down the bowl, temporarily putting aside thoughts of those unattainable communication solutions.

Before hoping for rescue from afar, he must first win this battle for survival.

He stood up and walked back to the control panel. The list of supplies, which he had already reviewed countless times, was brought up again.

"Mystery, a food unit, is estimated to last 66 days. But if I switch to a low-metabolism mode and reduce my daily intake to 1500 calories, how many days can I sustain that?"

"Recalculating..." Xuanjian responded immediately, "In the lowest metabolic mode, your physical and mental recovery speed will decrease by 45%, posing unpredictable health risks."

"But in theory, you can extend the survival limit of your food from 66 days to 110 days."

"One hundred and ten days..." Gu Yu nodded. Nearly four months.

"Next question," he said, his gaze shifting to the water unit, "120 liters of water. Calculate our water resource consumption limit."

"Understood." Xuanjian's voice became serious.

"First of all, the approximately 2.5 liters of water you circulate daily through drinking, excretion, and breathing are theoretically not consumed. The water purification system will treat all wastewater into an equivalent amount of drinking water."

"What we really need to calculate are the net losses that cannot be recovered."

A complex data chart unfolds on the screen.

"There are two main sources of net loss: airlock circulation and inherent system leaks."

"First, there's the airlock," Xuanjian explained. "When the airlock volume is 1.8 cubic meters, each decompression can recover 95% of the gas."

"However, there will still be a 5% loss of air containing water vapor. Based on your frequency of entering and exiting the cabin at least once a day, this alone will result in a loss of approximately 0.2 liters of liquid water per day."

"Secondly, there are inherent system leaks."

"The entire command cabin circulation system consists of hundreds of interfaces and valves. Even under the highest manufacturing standards, the daily evaporation and permeation losses are estimated to be around 0.1 liters."

"The conclusion is that, without considering any unforeseen circumstances, your net daily water consumption is approximately 0.3 liters."

"Your 120 liters of water supply will be completely depleted in about 400 Martian days."

Four hundred days...

This number seems to be much smaller than the stress associated with food.

"Captain, this 400-day period is based on the most idealized calculations, assuming you only maintain your own survival."

"Once the Seed Bank of Hope is launched and a hydroponic system is established, the daily additional water consumption will be between 2 and 5 liters, depending on the scale of cultivation."

"In addition," another set of data shows, "if you need to carry out industrial activities such as 3D printing, mineral purification, or electrolytic hydrogen production, these are also major water consumers."

"Once we enter the full development phase, the existing 120 liters of water reserves will be completely depleted in less than thirty Martian days."

Gu Yu felt a sudden tightness in his back.

The 66-day countdown for food is just the first hurdle.

The water crisis, however, is an even more terrifying boss.

Gu Yu's gaze finally settled on the names of the two steel behemoths. His plan became clearer and more urgent. "Xuan, our mission is clear."

"Within 110 days, I must use the Seed Bank of Hope to establish a self-sustaining food source."

"But before that, even in sync, I must successfully mine the underground frozen lake in the Land of Adventure."

"Transform our water cycle system from a constantly depleting closed loop into an open loop that can be replenished indefinitely!"

"Building nests, digging wells, farming... all of this is for survival."

He looked up again, gazing at the distant blue star on the screen.

"But if this life is destined to take place in eternal solitude, then how different is it from death?"

"Xuan." For the first time, Gu Yu's voice carried a hint of unconcealed weariness and confusion.

"I'm here, Captain."

"What's the best plan for tomorrow?" he asked softly.

"Based on the priorities you just determined," Xuanjian responded immediately, "you should carry out the water acquisition mission tomorrow morning, as this is the foundation for ensuring that all plans can be implemented."

"I know," Gu Yu said slowly, "I know this is the most rational choice, but..."

He paused for a long time, "But I still think that connecting with Earth is the real highest priority."

"Xuan," he raised his head, his gaze sharpening again, "discard those unrealistic plans with less than a 2% success rate."

"Think about it again carefully, use our brains, use the mindset of engineers, and think about it again."

"We must have overlooked something! There must be another way! Any way!"

Xuan fell into a long silence, this time without giving an immediate response...

Its massive computing core seems to be searching and calculating all the overlooked possibilities with unprecedented depth.

Just when Gu Yu thought there would be no more answers, Xuan Jian's voice suddenly rang out, carrying an uncertain tone.

"Captain, it seems we have indeed overlooked something."

"What?" Gu Yu's heart skipped a beat.