One of the lakes on Jupiter is found to contain water with extraordinary properties. This is of great interest to the scientists, but from being a matter of interest the water soon turns to being a matter of deadly peril to the planet.

Galasphere 347 is in deep space. After a comet collides with the ship, Dart and his crew discover a new planet beyond the orbit of Pluto. Touching down in the dense forest, Dart and Slim meet one of the planet's giant inhabitants

Slim is sent to Venus to investigate a mysterious disease which is paralysing the population. He finds a serious and highly dangerous state of affairs on the planet.

Tyrig plans to use a nerve gas to seize power on Mars. Raeburn discovers that Tyrig and his men have set up base on the Martian moon Phobos and Dart is sent to investigate. Dart and his crew are captured by Tyrig, who wants to use the Galasphere to spread the gas. Refusing to co-operate they are placed in a dungeon which slowly fills with sand

The Earth’s food supplies are in danger when an unknown fungus is found to be destroying all plant life. It is thought that leaves from a tree on Saturn will help to avert disaster and Dart is sent to collect them.

On a mission to Jupiter, Slim disappears in the swamps. Raeburn orders Dart and Husky to leave but trouble with the Galasphere's primary drives gives Dart an excuse to resume the search only to find that Slim has shrunk to dwarf-like proportions

Raeburn is contacted by Yria from Alpha Centauri who is seeking help to destroy an evil computer superbrain which is attempting to take over the planet Delta

The Galasphere is sent on a rain-making mission to Mars with a cargo of oxygen and hydrogen—the very ingredients escaped criminal Marog requires to complete his bomb under construction at his Phobos hideaway

Haggarty invents a robot that responds to thoughts. Dart tests the range of telepathic thought in space and investigates a new planet near the Sun unaware that the Neptunians have encamped there. Only Haggarty's new robot escapes the Neptunians' hypnotic influence

Exploring the Silver Forest of Venus, Husky becomes trapped in the web of a Spirigum Spider. Haggarty manages to free him and discovers that fragments of the web act as a truth drug. Raeburn, meanwhile, is offered the formula for Kinotine, which has the ability to store heat indefinitely. Kinotine's inventor, Dr. Mason, will donate the formula but when a call is received from Kolig, head of Mars's largest chemical plant, offering the formula for sale, Raeburn suspects foul play

The problem of dwindling supplies of Plutonite is solved when an asteroid made of the material is discovered. But before Raeburn has managed to secure the asteroid Miga, a wealthy Venusian has taken possession and intends to sell it. Raeburn reluctantly agrees to the asking price and sends Dart to complete the transaction

The Galasphere's Meson unit malfunctions and lands in the unexplored Tuhera jungle. Dart and Husky leave to fix the problem. When Husky fails to return, Dart follows and is captured by a giant primitive man. Husky speaks with the giant in its native language and they are set free. They return to Earth with some Martian fruit which makes hair grow—the perfect solution to Haggarty's problem

An asteroid has been deflected from its orbit and is heading straight for the capital of Mars. Colonel Raeburn, Head of SPACE PATROL, gives Larry Dart an almost impossible assignment - to destroy the asteroid.

Dart and his crew, seeking a lost party of scientists on Jupiter, come upon a band of criminals who are killing numbers of Lumis, the only wild animals on the planet.

When Colonel Raeburn finds that criminals on the moon are operating a Lazer [sic] gun against Earth he sends Dart to investigate. The Patrol Captain has a disturbing report to make on his return.

When Dart and his crew make an emergency landing on Titan to repair their galasphere, they make a curious and far-reaching discovery.

Colonel Raeburn is faced with a dangerous situation when a would-be dictator sets himself up on the satellite Ganymede and begins to interfere with the sun.

Professor Borra of Venus has invented a mechanical eye which can destroy any ship constructed of metal alien to Earth, Mars or Venus. The demonstration is impressive but what will happen when a Galasphere constructed from metal mined from Pluto comes within range?

To halt a virus destroying Martian vegetation, Dart is sent with a spray that is deadly to all forms of life except those native to Mars. When the spray comes into contact with a whirlwind, the chemical is rushed into space and is soon on a collision course with Earth

A strange jittering is affecting the city and other Earth locations. Haggarty discovers, by chance, that the jittering is caused by radio waves emitted by Uranus, where the Duos are once again planning an invasion

Saturn has a new leader. Riga is succeeded by his brother Simba and whilst Dart is en route to investigate, Simba launches rockets destined for Earth containing Saturnian grass seed—which absorbs oxygen and emits carbon dioxide

The Neptunians create a forcefield around the Earth containing particles with strong electromagnetic properties. The field begins disrupting electricity supplies, causing a complete blackout