For the second time in his life, Ji Xinghe boarded a spacecraft; the last time was when he left Azure Star for an Alien Planet. However, this time, he was not returning to Azure Star from Alien Planet, but to the near-earth space of an Alien Planet.
The region of space known as near-earth on Azure Star begins from 100 kilometers above the ground and extends to a spherical shell-shaped area of 36,000 kilometers. Forty percent of all spacecraft and one hundred percent of intercontinental ballistic missiles and submarine-launched ballistic missiles primarily operate in this space.
On an Alien Planet, the parking orbit chosen by spacecraft is generally a near-Alien-Planet point approximately 280 kilometers away, a far-Alien-Planet point approximately 59,000 kilometers away, with a period of two Alien Planet days. Although spacecraft at this altitude also need to adjust their orbits, the energy expenditure is negligible.
