While on a routine flight one of the rockets is hit by a meteor fragment. On Earth they run tests to discover the meteor is not only made of metal, but appears to have been artificially created. A second flight is launched immediately to retrieve more samples. What they discover may solve one of the greatest mysteries known to man.

A new project involves launching capsules of atomic waste into orbit and then assembling them with an atomic rocket motor. The unit is then accelerated for disposal into the Sun. The civilian Project Engineer, who will attach the a-rocket in space, is a former astronaut who resigned after a re-entry accident. He now lacks confidence in himself and is convinced that no-one else trusts him.

The first mission to Mars is nearing the red planet when a series of accidents and break downs put the mission in doubt. The crew must balance the need for caution and safety against the massive amount of scientific data that could be gained on such an expedition.

When an astronaut is stricken by a heart attack on the Moon, McCauley must find a way to get him back to Earth.

Trailblazer I is on route to the Moon when one of the crew gets word his wife has been hurt in a car wreck. Although distracted, the crewman needs to focus all his skills and abilities to overcome a major accident.

McCauley and two astronomers are on the Moon on Christmas day, and one of them is stricken with appendicitis.

Two scientists who can't get along are assigned to the same space station, and McCauley has to keep the peace.

A scientist's wife warns McCauley that her husband Perry's's co-worker Hal Carter is jealous of his success. McCauley doesn't believe her, but when Perry's theory about radioactive gas on the moon prove correct, Hal plots to kill Perry.

An asteroid straying close to Earth becomes the subject of an experiment. It is decided to scout the asteroid with a view of turning it into a mobile space station. If not the rock must be destroyed.

Col. McCauley is training a young cadet who wants to be an astronaut, and pushes the young man almost to his limit. When an onboard accident knocks out McCauley, the nervous young cadet has to bring the craft back to Earth on his own.

Four men a stranded after their spacecraft crash lands on the Moon. Their only hope of survival is to walk to Moonbase. All goes well till they realize the oxygen tank they are carrying to resupply themselves has a faulty valve. There is a way around the problem, but the cost may be too high for the team to accept

Senator Jim Sloane questions the need for and cost of a mission to the moon after McCauley's first effort to the moon fails and his second effort leaves a crewman seriously injured during takeoff.

A mission is sent to explore a cave system on the Moon in the hope of finding ice. Having a source of water available would enable the colonization of the Moon.

On the Moon the US and Soviets are in an informal race to be the first to Mars. Both sides play down the need to rush with concerns about safety. Ultimately both missions launch within minutes of each other, but a terrible accident completely changes the game and the ultimate fate of both crews.

His family watching from mission control, Col. Edward McCauley who is commanding the first rocket into outer space must make a desperate gamble when the second stage of his rocket fails to jettison.

Returning from the Moon with valuable spore samples the crew of MR7 are rendered unconscious. Earth sends a rescue mission but a decision has to be made that could put everyone's life at risk.

Shortly after leaving the Moon a spacecraft is hit by an asteroid destroying their oxygen supply. The three man crew now become engaged in a life and death battle to extend their oxygen supply long enough to make it home.

An eager, space-enthusiast technician (played by Robert Reed of The Brady Bunch) installs a smaller Guidance Control System he designed into the rocket ship. There is now room in the equipment bay for him to stow away on the next flight. But during the 12G takeoff his improvised couch crushes the equipment rack, causing the ship to lose all power before reaching orbit. The uncontrollable ship will quickly re-enter and burn unless repairs can be completed.

Col McCauley, while serving on the space station gets word his son has been seriously injured in a hit and run accident near the rocket base. Tension mounts as word comes through the driver of the car has been identified, and appears to be on duty on board the space station. With nowhere to run and nowhere to hide on the station, how will this terrible emotional conundrum be resolved?

A ship tasked with retrieving a malfunctioning Venus probe runs into issues when the scientist in charge, a friend of McCauley's insists on going despite previously disobeying McCauley's orders.

McCauley races against time in order to save an astronaut who is trapped when assembling the prefabricated units of a space station. The astronaut is the son of a air force general and trapped when his sleeve catches between sections of the space station.

A miss-fire of the MR28 sees the craft miss the Moon and head for deep space. The only chance of rescue is a new MX experimental rocket. In theory, the new ship should have the range. In practice, no one really knows.

A 3-man team visit the Lunar Observatory, isolated from all Earth signals on the Moon's far side, for routine Radio Telescope work. They pass the time during a long sky-mapping session by taping "A glimpse of lunar life" sound-broadcast. An power fault interrupts and requires a Moon walk to the Radio Telescope. One man is badly injured while returning. Unconscious for days, he responds to the tape-recording and deliriously asks to hear the "sound from the stars." His colleagues comply and make an interesting discovery.

Space station Astra is chosen for a medical experiment to measure men's reactions to stress and fatigue. The medical director is convinced he can quantify a person's reactions to strain and so prevent accidents. Then a life-threatening problem on the space station requires men to perform well beyond their limits. An inner "voice of infinity" is what they heard, enabling them to save the situation.

Colonel McCauley returns from Asteroid 78-1. The mission was cut short by the failure of his suit oxygen supply. He is insistent that just before he passed out he saw fossil evidence of life on the asteroid. Unconnected with this, Air Force medical staff have recommended his prolonged series of missions requires a 60-day 'grounding' to recover from stress. Will McCauley be able to lead the return mission to the asteroid if its unpredictable orbit permits another rendezvous?