Cybernetic Tyrant and Deep Space Visitor

Two books in one volume Cybernetic Tyrant Mark and the team have returned from deep space and discover that NASA seems to be run by robots. They are met by one in Earth orbit which refuses to allow them to communicate with Houston and also has locked the visiting scientists from Herade in the passenger compartment. It assumes the aliens are animals and stops all communication between the two species. Finally, Mark, Anna, Bill, Chan and Mary are shipped back to Earth, but the reception they receive is totally unexpected and frightening. What has happened to their friends and colleagues while they've been away? Deep Space Visitor - a second adventure in the same volume. After celebrations to welcome the Heradians, Mark's team are discussing how much help they need to occupy their original world in the Trappist-1 system. Development work on the spolding drive has meant that an expedition is also being planned to the pristine Earth the team had accidentally stumbled upon on the first main Trappist-1 expedition. Just when they begin discussing the plan, Anna walks into the office and announces more information on a vague signal being received from deep in the solar system between the orbits of Saturn and Uranus. What is it, and why does it lead to a spolding expedition to Nu Lupi, almost fifty lightyears from Earth?