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.

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

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.

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.

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.

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

It is decided to attempt fuel transfers between space craft while flying in orbit. The requirement for precision control of two spacecraft is met by using a pair of specially trained twins. Safety is the primary concern, but ensuring this, they overlook one potential fatal flaw in the mission

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

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.

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.

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.

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.

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.

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?

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.

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.

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.

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.

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.

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.

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.

Ship MR34 loses Auto-Control during landing and crashes 200 miles from Moon Base. Two of the crew survive and make for a nearby fuel-cache. Can they use the liquid oxygen there to improvise a survival igloo?

A Soviet Major is the sole survivor of a crash landing near a US advance moon station. Determined to appear blameless, he reports Americans sabotaged the landing and then takes drastic action to destroy all evidence.