Mark Lee gazed out of the porthole, watching as Earth gradually shrank in size, turning into a blue sphere in the dark void of space. Silence reigned aboard their ship, broken only by the steady hum of the life support systems. Everything he had dreamed of since childhood, all the years of preparation and training, had led to this moment—the moment when their mission began. A mission that could change the future of all humanity.

He and Lee Donghyuck had been sent on a three-year expedition to a distant planet, potentially habitable. Their task was to conduct research and determine whether humanity could colonize this planet, should Earth become uninhabitable. This was not just a scientific mission; it was a chance to save millions of lives.

Mark took a deep breath, feeling his heart tighten under the weight of responsibility. It felt as though he had left a part of himself on Earth, where his girlfriend was waiting for his return. Every moment of their parting had felt like an eternity. In her eyes, he had seen pride and love, but also a shadow of worry. He knew he had left a heavy burden on her shoulders—the burden of waiting, hoping, and fearing. This realization pierced him to his core, but he knew he had to take this step. For her, for everyone left behind on Earth.

He clenched his fists slightly, trying to gather his thoughts. "Donghyuck," he finally said, his voice cutting through the silence. "The instruments are working fine, and we're on course. Keep an eye on the readings, especially the communications with the base. We can't afford any mistakes."

In these moments, as their ship moved farther away from Earth, Mark felt both calm and tense. He knew that challenges, uncertainties, and trials awaited them. But he also knew that by his side was a reliable partner and friend, with whom they could overcome anything.

Closing his eyes for a moment, he sent his thoughts back to Earth, to the one who was waiting for him. He would return. He would return for sure.