Setting Sail

After reaching the fifth stage, the Hope will maintain a rotational speed of approximately 1.27 rmp for transportation, and then embark on its interstellar journey.

Although humanity has lived on Callisto for decades, it pales in comparison to Earth. It's important to remember that human physiology, cellular memory, development, and genetic information have all evolved to adapt to Earth's environment.

This process has taken over four billion years, starting from the first single-celled organism.

Therefore, Earth's gravitational environment is always the most suitable for humans, no matter the circumstances.

It is precisely for this reason that the New Government decided to set the Hope spacecraft's final simulated gravity to a value similar to Earth's environment.

Moreover, the rotational speed of 1.27 rmp avoids the adverse effects of the Coriolis Effect on humans, indicating that the Hope spacecraft has met its design expectations.

More than a month passed quickly. During this time, the spacecraft's rotational speed gradually increased in stages, and people went through round after round of adaptation, rediscovering the feeling of Earth's gravitational environment.

In reality, if the hibernation time is included, most people have theoretically lived in the Callisto environment for decades, making it impossible to readjust to Earth's gravity in just over a month.

However, due to the needs of space development, humans had developed related drugs to aid this adaptation process even before the disaster.

When the human body adapts to a microgravity environment, the total amount of fluid in the body decreases by a full liter, and because the cardiovascular system does not need to overcome gravity to supply blood to the brain, the function of the heart muscle gradually weakens.

Restoring the body to Earth's gravity requires a slow process.

"Hope, set sail! Target: Ross 154."

After everyone had adapted to the spacecraft environment, Yue Yuan finally issued the order that he had been waiting for for more than forty years.

This target was not chosen randomly, but was determined by astronomers after decades of observation.

According to normal thinking, going to the nearest star would be the best option, but Proxima Centauri, including its Centaurus Trinary Star System, had already exploded, so humans naturally couldn't go there.

Therefore, scientists had to choose another destination.

After decades of analyzing Callisto's direction and speed in space, the direction of the dust cloud after the supernova explosion, and comparing several of the closest stars to humanity, considering the number of planets and the possible distribution of resources, they finally came to the conclusion: Ross 154.

In terms of distance, there is actually an even closer star, Wolf 359, which is only 7.7 light-years away. It was originally the preferred destination, but its system only has two planets: one rocky planet and one gas giant.

According to scientists' observation data, the rocky planet is still close to its main sequence star. Based on its orbital position and the surface temperature of the main sequence star, the surface temperature of the rocky planet is very likely to remain between 480 and 500 degrees Celsius.

Humans simply cannot mine resources on such a harsh planet.

Ross 154 is much better. According to the Radial Velocity Method, humans know that it has seven planets, two of which are likely to be giant gas planets, and the other five are rocky planets. The key is that the five rocky planets are not the closest to the main sequence star. The Radial Velocity Method, simply put, is a way to detect whether a star system has planets based on the gravitational interaction between the planets and the star.

It is one of the seven methods for detecting exoplanets, roughly based on measuring the gravitational influence of a planet on its main sequence star. When a planet orbits, its gravity causes the star to "wobble" slightly. The larger the planet, the greater the impact on the star.

This "wobble" of the star can tell people how many planets a star system has and how big they are. Because it captures the tiny wobbles caused by planets orbiting their stars, moving closer to or further away from Earth, this technique is also known as the Doppler method, because it measures the shift in the star's light caused by gravity, which changes the color of the light.

Scientists speculate that in addition to the five rocky planets, there should be many satellite systems, which is simply paradise for humans today.

Moreover, although Ross 154 is a red dwarf star with a surface temperature of only 3470 Kelvin, which is 3196.85 degrees Celsius, with today's human technology, as long as it is a luminous star, there is a way to obtain energy.

With Yue Yuan's order, the Hope—the ship carrying all of humanity's hope—finally embarked on this long journey of 9.545 light-years.

Ross 154 was originally about 9.693 light-years away from the Solar System, but Callisto carried humans for a distance, so when the Hope set sail, it became 9.545 light-years.

The light of nuclear fission illuminated the dark Callisto, and the azure flames illuminated the silver Hope.

Located in Callisto's synchronous orbit, the Hope began to slowly change its orbit under the propulsion of three huge Fission Thrusters.

Its orbit began to change from a circle to an ellipse.

Yes, unlike the awesome interstellar voyages in novels, the Hope did not rush out of Callisto's synchronous orbit all at once. It needed to change its orbit, change its orbit again, and then fly out with the help of Callisto's gravity.

That's right, a gravity assist.

Although Callisto's mass is pitifully small and not suitable for use as a gravity assist planet, humans now have nothing but Callisto.

Energy-starved humans are naturally unwilling to let go of any usable power, and humans also need to correct the Hope's direction of travel during the orbit change.

Slowly, the Hope's circular orbit became elliptical, and then became a flat orbit.

In the following days, the Hope orbited Callisto like a comet, sometimes far and sometimes near. At the same time, the humans on the Hope were preparing for the final lap of acceleration.

"All parameters have been corrected. The Hope is about to enter the acceleration phase."

Hopeful shouts rang out again in the command center.

"The Hope's attitude has been adjusted. It is expected to enter the predetermined acceleration orbit in one minute and twenty-three seconds."

"All members of the engine team are in position. The main thruster will enter full power operation in one minute and twenty seconds."

"External camera signals are normal, now connecting to screens throughout the Hope!"

Listening to the reports, Yue Yuan sat calmly in the captain's seat. The image on the large screen in front of him was now divided into nine, displaying nine external views, resembling a tic-tac-toe grid.

The images included a half-body shot of the Hope, the long tongues of flame spewing from the Fission Thrusters, and the dark starry sky filling the screen. Of course, there was also the receding figure of Callisto.

"Goodbye, Jupiter's fourth satellite—Callisto!" Yue Yuan murmured in his heart, watching Callisto slowly fade from the screen.

Callisto still bore numerous traces of human industry, including many immovable factories and super-large machinery and equipment. Humans had not destroyed these things; they would represent the traces of humanity's presence, accompanying Callisto on another journey of wandering, disappearing into the vast sea of stars.

If a civilization had incredibly good luck, they might encounter it in the distant future.

However, this was no longer something humans could concern themselves with. In fact, there was another reason why humans didn't blow up the remaining projects and super-large equipment: to save energy.

While Yue Yuan was reminiscing about Callisto, the light from the Hope's Fission Thrusters suddenly intensified. The strong interaction force allowed the Hope to completely break free from Callisto's gravitational field, slowly disappearing into the boundless starry sky.

This was humanity's first interstellar voyage in history, and also a one-way interstellar voyage.

9. 545 light-years was an immense distance. Even traveling along the direction of the remaining Interstellar Dust's diffusion, humanity still had no room for error. But if they didn't set sail, they wouldn't even have a chance.