December 21, 2037, Rocket City, Sazhou, Bright Country
Today was the winter solstice, and Daphne's thirty-eighth birthday. Little Vito was already seven. He ran around the yard, sometimes grabbing Michael's strong arm and hanging from it, playful and adorable.
The prefab house where Michael and Daphne lived faced the bay, with the launch site on the coastal mudflats clearly visible. The Flamingo 13 Heavy Rocket stood tall on its launchpad, and the VESSEL Great Ship probe was about to blast off.
1977 had been calculated by astronomers as the best launch window for sending probes from Earth to the outer Solar System. Thanks to the fortuitous positions of the giant planets in their orbits, a spacecraft launched from Earth could pass Jupiter, Saturn, Uranus, and Neptune in succession.
While visiting these giant planets, the spacecraft could also use their gravitational slingshot effect to accelerate, eventually flying out toward the edge of the Solar System. Such a window came only once every 165 years.
In August and September of that year, the Bright Country Space Administration launched Voyager 1 and Voyager 2. Thanks to the efforts of astronomers, the spacecraft systems had been repaired multiple times over vast distances, and even today they could still communicate with Earth.
A full sixty years had passed. Another 165 years? Michael didn't want to wait another hundred.
Fortunately, the VESSEL Great Ship's mission wasn't to explore the giant planets. It was to search for X Planet and send humanity's second calling card. Although Michael had improved the spacecraft's propulsion system, it was still necessary to give the ship as much speed as possible.
Jupiter and Saturn had a conjunction cycle of about twenty years. In the sixty years since 1977—three cycles—their relative positions in the sky had become almost the same as before.
So