Exploration of Mars
The Viking program launched "Viking 1" and "Viking 2" spacecraft to Mars in 1975; The program consisted of two orbiters and two landers – these were the first two spacecraft to successfully land and operate on Mars.
The primary scientific objectives of the lander mission were to search for biosignatures and observe meteorologic, seismic and magnetic properties of Mars. The results of the biological experiments on board the Viking landers remain inconclusive, with a reanalysis of the Viking data published in 2012 suggesting signs of microbial life on Mars.
The Viking orbiters revealed that large floods of water carved deep valleys, eroded grooves into bedrock, and traveled thousands of kilometers. Areas of branched streams, in the southern hemisphere, suggest that rain once fell.
Sleepers of Mars
While on the planet in the previous story, the Soviet and British crews had explored part of Mars around their landing sites, discovering vegetation plant life, in the form of scrubby bushes growing along the banks of ancient canal works, with sluggish water still in them. The planet also hosted AI robots, hostile to the visitors from Earth. They seemed almost wild, feral machines living without control of organic life. Due to fatal encounters with these robots, and ill planned gunfight with the British crew, the Soviets now number four crewmen. Preparing to depart for Earth they discuss the fate of their mission - originally a race between the nations of Earth to be the first to reach Mars. The British and the "Gloria Mundi" had won the race, reach Mars before the Soviets and United States (whose rocket had crashed with no survivors upon reaching Mars). The Russians speculate what would be the global reaction if the "Gloria Mundi" reaches Earth, and then the Soviets return, and claim that they were the first to land on Mars, not the British. They conclude that they would not be believed. However, they reason that if they succeed in racing the British home, then they can claim that the USSR was the first to conquer the Red Planet, and the British will be disbelieved.