Earth Crisis Rescue Operation

In 2200, due to the invasion of aliens, the earth is about to become an alien colony. Fortunately, the invading alien civilization is only one level ahead of human technology. As long as the news is known in advance, all forces can be united to develop technology. In order to save the earth, people risk great dangers and take time-traveling spacecraft to inform humans more than a hundred years ago. However, due to a malfunction in the spacecraft, the time travel was not smooth. This book mainly introduces the tortuous story of the three protagonists in saving the earth after the malfunction.