Yamato Origins, Part 4: Asteroid Ship Icarus

After Keisuke Fujikawa, the next author to become involved was SF novelist and television writer Aritsune Toyota, He wrote a separate proposal either in parallel or just after Fujikawa’s (the timeline is somewhat hazy on this point) which began from the same premise and went in a slightly different direction. Toyota’s working title was Asteroid 6, which became Asteroid Ship when Nishizaki decided this was the way to go.

Toyota wrote this brief essay about the project in 1982:

I first met Mr. Nishizaki through Eiichi Yamamoto, who was my boss at Mushi Pro Studio at that time. Mr. Nishizaki had read Methusulah’s Children by Robert Heinlein and wanted to create an SF space anime. This was the clincher for me to become involved in the writing of Yamato for the next ten years.

I wrote the basic ideas and SF concepts. The premise was for the Earth to be completely contaminated. It was my idea to build an Asteroid Ship which would travel over 20,000 light-years to retrieve a radiation removal device.

In fact, this is “Journey to the West.” In other words, it is extrapolated from a familiar story in which the local world of Central Asia has fallen into disorder and a passage is made into Western regions.

Because I wrote the original proposal, I was scheduled to write the first draft of episode 1. Instead I became involved in another series [the live-action Monkey Army, a Japanese takeoff of Planet of the Apes] and could not participate.

Here is the complete text of Toyota’s story proposal, which is an expanded version of his Asteroid 6 concept. (No obvious reason existed for the Asteroid 6 title, since there were more than six characters and fewer than six spaceships. Hence the name change.) The art shown below was created in summer 1973 for the first plan book that promoted the series to prospective sponsors.

Asteroid Ship Plan

The Setting/Background of the Era

At the beginning of the 21st century, Earth was attacked by aliens from the mysterious Planet Rajendora. Nuclear missiles flew in from distant space and covered the Earth in burning fire which dispersed poisonous radioactivity around the globe.

Earthlings resisted the Rajendorans by building cities deep underground where it was still possible to survive, but even these will become unsafe if the missile bombardment continues.

However, one day the attack suddenly stops. People in the underground cities are overjoyed, but then a terrible truth is discovered. The Rajendorans did not give up the attack; rather, they judged that it was no longer necessary. The entire surface of Earth is now covered in boiling magma in which no life can survive. The only plants and animals that remain are those useful to humans underground.

Radioactivity from the surface is gradually seeping downward. Moreover, it is only a matter of time before the energy reserves of the city dry up. Therefore, the Rajendorans no longer have to raise their hand to defeat the human race. Instead, they can now coldly watch as Earth slowly perishes like a half-dead animal, a far more cruel measure.

The surviving scientists discuss this serious situation. Their research determines that makind has only one year left. What should be done? Will they wait in silence for extinction?

A boy appears in the assembly hall and offers up the only solution: on the surface of Mars, Mariner 18 has identified the wreckage of a spaceship that seemingly crash-landed there several thousand years ago. The data left in the wreckage of the ship has been decoded. It is determined that it originated in a solar system over 20,000 light-years away, from a planet called Iscandar.

The advanced civilization of this great planet has the technology to eliminate radioactivity. Perhaps they can save the Earth from its terrible fate.

The RNA of many dead scientists has been implanted in the brain of this boy, and he now carries their cumulative knowledge.

Footnote: RNA is Ribonucleic Acid, the material responsible for memory. For example, two mice (A and B) take part in an experiment. Mouse A is trained to take the bait when a door is opened. Mouse B is not given this training. When mouse A’s RNA is transplanted into the brain of mouse B, it then takes the bait when the door is opened.

A conventional electric-powered transport cannot be trusted to make the voyage from the dying Earth to Planet Iscandar.

It seems that a planet once existed between the orbits of Mars and Jupiter, but now it has broken up into 44,000 pieces. It is here that an Asteroid Ship can be built. An asteroid can be hollowed out and equipped with an engine modeled after the one in the crashed spaceship from Iscandar.

This is the Asteroid Ship.

If it is built from the 770-km diameter asteroid Ceres, it can accommodate 100,000 people. Additionally, the 2-km diameter Icarus can carry dozens.

Various devices are built into this Asteroid Ship. Although it looks like the Imperial Palace, it is equipped with nuclear missiles, high-speed warships, and the best achievements of Earth science.

Many dangers must be waiting in the 20,000 light-years between the asteroid zone and Planet Iscandar. The Rajendorans could be taking their hateful breaths on the planets of other solar systems.

Morevoer, there is only one year left.

Many surviving Earthlings are sent to the Asteroid Ship where they become Asteroid Soldiers and launch in their mission to leave the solar system. But an automated Rajendoran observatory on Pluto catches sight of Icarus as it begins its voyage.

The Asteroid Soldiers will experience adventures on many varieties of planets on the way to Iscandar.

About Asteroid Ship Icarus


Asteroid Ship uses the asteroid Icarus, which has a 2-km diameter. It contains an antigravity engine with continous acceleration.

Footnote: The accelerating force: even though Icarus is a large rock, its engine output is superior because there is no air resistance in space. But there is danger of being burned by friction when entering the atmosphere of a planet, so the ship cannot go into action wherever the crew wants.

High-speed warships are stored inside Icarus; when acting in the atmosphere of other planets, they launch into battle or a reconnaissance mission.

Various equipment is stored on the surface of Icarus and many other locations. It is, so to speak, Tankuro.

Footnote: Tankuro was a character who appeared in the manga Children’s Club, published in the early Showa era. Its arms, legs, wings, cannons, etc. all emerged from the body of an iron ball.

When all equipment is withdrawn, the ship only looks like an asteroid.

The Rajendorans have devasted many planets and established bases there.

There is an area of space where ten Rajendoran ships are grouped together. It can be assumed that Icarus passes through while camouflaged as drifting stardust. (Note: this idea was used in TV episode 9.)


The outside of Icarus seems to be a rock lump, but the inside houses its mechanisms and the Asteroid Soldiers. Therefore, various equipment is available for life support and recreation.

Image Garden:

Vegetation from Earth is planted here, and an image is projected on a wall screen showing scenery from Earth’s past. Seeing this, the Asteroid Soldiers become more determined to continue their fight to reach Iscandar.

Image Bed:

When lying in this bed in a semi-hypnotic state, a user is surrounded by an image on a screen that simulates dating and traveling. (Note: this idea became the holography room in the TV series.)

Sky Swimming Pool:

This area’s gravity can be adjusted for ten minutes. Asteroid Soldiers can wear wings to fly in here or play space sports to their heart’s content

Garden lobby:

An area in which real trees grow and flowers bloom, created to ease the hearts of the crew. In addition, various events and meetings are held here. Men and women of Icarus occasionally come here to take a break from the other facilities or to find solace when disputes arise. This is an important way to avoid problems during missions.


It is 20,000 light-years to Planet Iscandar. Attacks and interference from the Rajendorans are expected during the voyage. Icarus carries equipment and weapons to resist them.

Image Projector:

A device that can project images into empty space. It is possible to give the illusion of many Icarus ships or an entire spacefleet. It is also useful for creating the illusion of robots, monsters, etc. to lure the enemy. (Note: this became the projection system used by Volgar in TV episode 17 to create the Balanosaurus.)

Balloon Dummy:

Because the Image Projector can be undone by radar, various ship models are prepared for quick inflation with high-pressure gas at a moment’s notice. Various models exist in various scales from the size of a Space Soldier to the size of Icarus itself. (Note: this idea was used in TV episode 11 with the balloon dummy of Yamato.)

Heat Ray Gun:

Also called a blaster or plasma gun, it has enough power to incinerate anything.

Nuclear Bazooka:

An atomic bazooka gun. Conventional nuclear material such as uranium or plutonium is needed in large amounts to create a nuclear explosion, and thus are too large to be used in a handheld bazooka. Therefore, this weapon uses Californium, which has a smaller critical mass (as little as 1.5 grams) and is currently used by the US Armed Forces. 1.5 grams is small enough to fit into a bullet!

Ray Gun:

A handgun that fires laser beams; can be set to stun level, kill level, or destruction level.


When communication with Earth is not possible during a crisis, it is anticipated that panic could set in among the crew. Thus, preventative measures are necessary.

Cold Sleep:

Literally, it is a cooling device that the crew can use to avoid catastrophe by going into hibernation. (Note: this appeared in TV episode 2.)

Earth Day:

A party to celebrate the Earth. Other events such as Christmas and New Year’s Day can be reproduced. (Note: this became the farewell party in TV episode 10.)

Simulation Event:

A simulated crisis can be performed for training purposes, known only to the main computer or a crew leader. A false crisis can be devised to strengthen the unity of the crew, but once it is uncovered it could cause them to become divided.

It is impossible for Earth to communicate with Asteroid Ship Icarus using conventional radio, since both the ship and electromagnetic waves travel at the speed of light. Therefore, messages are transmitted using warp communication, which is similar to the warp method of space travel. However, Icarus cannot communicate during warp navigation, so it must revert to standard navigation.

On Earth the entire surface is now a sea of magma and there are no constructs above ground level, but an antenna for communications with Icarus must protrude from the land. A huge pedestal of heat-resistant concrete is built and a 2,000 meter antenna is placed on top of Mount Everest.

Because this is the only lifeline between Earth and Icarus, it is protected by four stationary satellites armed with nuclear missiles in orbit at 1700 km.

Even though the communication center is located several thousand meters underground, it must be shielded by layers of lead and concrete to block radioactivity. Its power is supplied by geothermal energy and can continue operating if other underground installations are destroyed. Even if an emergency occurs underground, no citizens are allowed access to the communications center.

Costume studies by Kazuaki Saito

The Characters

The characters are created for viewers in the upper elementary school grades, and super-heroes are avoided. Given the critical situation of the story, the youngest characters would be 15 year-old boys. For example, the greatest danger arises from a struggle over leadership, and only solutions that promote unity must be used.

Hans (German): Architect of the Asteroid Ship plan. He was injected with the RNA of dozens of scientists who all died, making him into a treasure house of knowledge or a human computer. This affects everyone else’s impression of him, which sometimes makes his life difficult.

Jeanne (French): A female Leader. She is respected by men, but unpopular with other women. This situation may lead to a crisis.

Yamaga (Japanese): The crewmember most trusted by Jeanne. He is an expert with a ray gun and quick to act, but he has no personal desire for power. This makes him a natural leader.

Muginga (African): Claims to be determined to exact justice for the human race, but it is really only in it for himself. His goal is to become a leader.

Tamara (Russian): A blond beauty who is unhappy when she is not the mens’ center of attention. Deeply jealous.

Somchai (Tai): A large man, a martial arts expert.

Imre (Hungarian): He seeks the approval of Yamaga and Muginga, but turns around and speaks ill of them when they are not around; a difficult person to get along with.

Lian (Chinese): Nothing shakes him, a staff officer with excellent perspective and judgment. Does not speak much unless asked a question.

Kashim (Indonesian): A man with a strong and capable mind, but his abilities do not match up.

Costume studies by Kazuaki Saito

Schematic Diagrams

Asteroid Ship Icarus will make a grand voyage and encounter a variety of phenomenae that become the setting for great drama and crisis.

Our galaxy is 10 million light-years in diameter and contains approximately 10 billion suns. Our sun is the largest object in our solar system, 600 times bigger even than Jupiter. Even by a low estimate, it is believed that there are no less than one million solar systems that support biological life. It is estimated that solar systems with higher life forms number several thousand less.

Other solar systems which are relatively close to Earth are as follows:

– Proxima Centauri, Alpha Centauri: 4.3 light-years.

These two are binary stars (Note: binary stars are two fixed stars locked into each others’ gravitational pull. From a distance they can look like one object but show two individual orbits when more closely examined.)

– Sirius: 9.7 light-years away in Canis Major.

– Procyon: 12 light-years away in Canis Minor.

– Barnard’s Star: 8 light-years away.

– Vega: 27 light-years away.

– Stars in the constellation Tau Ceti.

There are many independent regions in galactic space. A great deal of interstellar matter exists, such as nebulas and star clusters, which exhibit a variety of phenomonae.

1. The Fourth Planet of Fixed Star Zaraku

The same hemisphere is always turned toward the sun. The 800-degree daytime zone never experiences a sunrise or sunset and is inhabited by metal men. The night zone is constantly frozen at 200 degrees below zero, experiences neither noon nor midnight, and is inhabited by ice men. Either the metal men or the ice men are controlled by the Rajendorans.

Icarus must stop at this planet for a supply of high-tensile steel.

2. Space Current

A band of flowing particles that cannot be crossed; travelers must detour around it. Icarus is damaged when it enters the current and becomes entangled in it. There is a Rajendoran space fortress waiting on the opposite side, so Icarus must either detour into it or try to plunge forward in a straight path.

3. Red Giant Star

There is a planet whose sun is due to erupt at any time. Though the residents have migrated to outer planets, they now must emigrate to another solar system. They have the ability to travel between planets, but not to navigate between fixed stars. The Icarus crew is aware of this, but is at a loss about whether or not to help the planet’s residents.

The red giant is an aged star. Helium collects inside it, swelling it like a balloon. One day, our sun will go through this process, too. When that happens, it will swell into the Earth’s orbit and swallow our planet.

4. Super Nova

Icarus encounters a supernova, an explosion hundreds of millions of times more energetic than our sun. This is the result when a red giant star reaches the limit of its expansion. It is extremely bright, but fades as it stretches across 10 light-years. It is possible that the star that shone for three days over Bethlehem during the time of Christ’s birth was a supernova.

5. Radio Star

Causes instruments to go haywire during an encounter with a Rajendoran fleet.

6. Dark Nebula

A region of gas through which light cannot penetrate. Icarus flies through one of these dark clouds which block the view, so they are unable to see a Rajendoran gas mine on the other side.

7. Quasar

A quasi-stellar object which emits powerful radio waves when viewed through a radio telescope. It may be a star, but is not visible through a conventional telescope. Its true nature is unknown.

8. Black Dwarf Star

The remnant of a fixed star that has burned out and is no longer luminous. Icarus encounters one when coming out of a warp, and cannot avoid it. The ship barely skims across its surface.

9. Black Hole

Literally a hole in space that emits no visible light, a non-Einsteinian object. It is a portal into another dimension. (Note: this idea became the dimensional “dead zone” in TV episode 15.)

10. Fixed Star Gravar

A huge gravity well around a fixed star. For example, a single cubic centimeter of material from Sirius (in Canus Major) weighs 10 tons. The surface temperature is 2,000 degrees. (Note: its diamater is 1.8 times larger than our sun, but it appears 20 times brighter.)

As Icarus approaches Gravar, it begins to pull on the outer shell. Weapons, food, and other materials are thrown overboard and the ship passes safely. Despite the danger of attack by Rajendorans, Icarus must stop at a spaceport in Gravar’s solar system to resupply.

11. Resupply Operation on a Low-Gravity Planet

This planet has only 0.1G, which decreases weight significantly. People can wear artificial wings and fly. It is the same for the Rajendorans, and an aerial dogfight begins.

12. High-Gravity Planet

This planet has 2-5 times more gravity than Earth (2G Ð 5G). A person weighing 60 kilos on Earth would became 120-130 kilos here. Members of the Icarus crew are barely able to move with an automated Rajendoran weapon about to attack, but they get help from a creature of this planet which resembles a stick insect.

13. Robot Planet

A planet itself becomes robotic from the relics of its long-dead inhabitants. Crewmembers who land there appear to be no different from the indigenous people, and the planet believes them to be its masters.

14. Globular Cluster

A cluster of thousands of stars grouped together into a giant sphere, through which it is impossible to warp.

15. Variable Star

A fixed star which “beats” like a pulse. It grows and shrinks periodically.

16. The birth of a Star

Floating gas and dust exist as interstellar matter between fixed stars. They are only tiny particles, but can gradually aggregate together and begin rotating to form a new star.

17. The Spectre of Green Sodium Interstellar dust

(Spectrum: the color of a fixed star.)

When the temperature is very high, a star has a blue tint. Vega is an example of this Type-A star, a blue sun with a surface temperature of 12,000 degrees. Vega should look yellowish-green when seen from inside the atmosphere of one of its planets.

In a Type-G star, the surface temperature is around 6,000 degrees and the star has an orange tint. In a Type-M star such as Antares, the surface temperature is 3,000 degrees and the tint is red.

18. Supergiant Star

A fixed star which is one million times the size of our sun.

19. Triple Stars: A planet with three suns.

20. Gas Nebula

21. Open Cluster

22. Stone Sun Group

Story Ideas

As the plot advances, many planets are visited for many self-contained adventures.

1. An Earthling Slave on Planet Uru

Icarus parks in orbit around Planet Uru and a warship drops to the surface for reconnaissance. The crew must wear masks and tails to pass for inhabitants of this planet. The civilization of Uru is in a developmental stage similar to ancient times on Earth, and one Earthling is sold in a slave market. Muginga’s strong sense of justice motivates him to interfere, but Yamaga objects and they argue. In fact, this can lure in and trap Rajendorans who are waiting for Earthlings to appear.

2. Dimensional Rift from a Planet Bomb

An Asteroid Soldier travels down to a planet with binary suns and finds a planet bomb. Medieval-type people fear the bomb and sacrifice a princess to pray for their protection. Muginga intervenes and the landing party falls into a dimensional rift. They have to fight huge monsters and ghostlike creatures who live there.

3. A graveyard of Planet Sargasso

Control of Icarus is suddenly lost. It is pulled into an eerie region of space among the wreckage of hundreds of space ships. In mathematics, there is an equidistant point between two gravitational fields (in this case coming from fixed starts) called a LaGrange point which interferes with gravity. In this case, the wreckage of space ships, dust, and other material drifts into this graveyard of space. A spider-like creature who eats energy dwells here and attacks Icarus. (Note: this idea was modified into the Magellanic Stream in TV episode 15.)

4. The Girl of the Robot Planet

An Asteroid Soldier lands on a Robot Planet and discovers a girl there. She is an android; she has braved death and tragedy trying to escape from Rajendoran rule. Once again, the soldier witnesses proof of their brutality.

5. An Invader from the Meteorite Group

Icarus flies through a large group of meteorites but does not received severe damage. However, starship-shaped parasites which were attached to the meteorites grab onto the surface of Icarus and get inside. They take possession of a soldier by attaching themselves to his back and attempt to take control of the ship.

6. Space Wanderer

Icarus encounters a space ship from Earth for the first time, but there are no survivors on board, only a female-type robot. This robot is a caretaker of children who were born on the ship and are now being held hostage by Rajendorans. The robot is a lure for the asteroid soldiers…

7. Red Giant Star SOS

Icarus approaches a planet orbiting a huge red giant star which is expanding as it dies. The inhabitants of this solar system used to live on the fourth planet, but have taken refuge from the swelling sun on the fifth, sixth, and outer planets. They do not have the technology to escape the system by interstellar travel, so the Asteroid Soldiers move to help them escape.

As the red giant nears its point of explosion, a Rajendoran ship suddenly appears. Should the soldiers return to Icarus and escape, or continue helping the citizens?

8. Phantom Ship

An alien spaceship filled with corpses has been wandering the stars for centuries. It is actually a trap set by the Rajendorans to attract curious Earthlings.

Time Table for the Voyage from Earth to Iscandar

The farthest stars that can be observed from Earth are 500 light-years away. Beyond that lies the world of the unknown. Not a single star system has been detected that can serve as a port of call. The potential for resupply is zero.

The distance to Iscandar is 20,000 light-years. One warp allows a jump of 100 light-years and can be performed twice a day. Thus, the maximum distance covered in one day is 200 light-years, which means the round trip will take approximately 300 days.

Because fixed stars and solar systems in the Milky Way are sparse, warps can be performed many times repeatedly. Although various dramas will unfold along the way to Iscandar, the consequences are always considered to be obstacles.

– The progress of Icarus is interfered with by a huge gravitational field.

– There is a region of too many solar systems, so it becomes impossible to warp. Or, a forced warp damages Icarus.

Icarus almost collides with an undetected black dwarf star (a small, dark star with no visible glow).

Icarus is caught in a field of Rajendoran space mines and cannot move.

Icarus is caught in a meteor storm.

Icarus is drawn toward a wandering magnetic asteroid and becomes irrevocably stuck. It is ten times the size of Icarus, and if the engine is pushed too hard it will overload and burn out.

Icarus encounters a Rajendoran space fleet and will lose three days if it detours.

Icarus is caught in a space current (a flow of atoms such as carbon or oxygen) and swept off-course.

– An nuclear missile misfires and its energy is attracted by Icarus indefinitely

Icarus gets caught in the wake of a supernova explosion.

Icarus enters a globular cluster of over 2000 stars.

Icarus enters into a dark nebula.

Icarus falls into a black hole.

In unavoidable encounters with these objects, Icarus is damaged or loses supplies, and must find a port of call in a nearby solar system. Inevitably, the hand of Rajendora circulates there.

Concept art for Rajendoran spaceships, Kenichi Matsuzaki

The Mystery of Rajendora

The Rajendorans attempt to destroy the Earth, and though they should be despised, their true nature and the location of their home planet are mysteries.

The Rajendorans

They are never actually seen. Their breath can be viewed through a special polarized lens. They reflect light and emit radioactivity that can be detected by a Geiger Counter. When one of these bizarre space creatures is caught, their identity is finally understood: it is a robot made from organic cells.

Moreover, these robots look just like Earthlings so they are difficult to detect and destroy. Anyway, Rajendoran ships, monsters, spies, etc. give off a phosphorescence that can only be seen through a polarized lens. Their form is always artificial and their real nature is not well understood.

In truth, these are just minions. This is not discovered until the end, but actual intelligent aliens called Rajendorans no longer exist. They died out 100 years ago along with all other creatures on their planet. The only survivor now is an ugly, climbing plant.

The True Nature of Planet Rajendora

The Rajendorans built a huge computer network on their planet. The computer’s imperative was to protect the environment, but it was already too late to prevent the extinction of life. Only the climbing plant was saved. The autonomous and self-perpetuating computer judged that to save this plant, it must be transplanted to another world.

It attempted to take over the Earth, but overestimated the need for nuclear missiles and ceased the attack when no room remained for the transplant.

The Asteroid Soldiers learn this truth when they explore a temple on Planet Rajendora, and they stomp the ugly climbing plants to death. The computer immediately explodes, since its only purpose was to protect creatures of Planet Rajendora and it is confirmed that last one is now dead.

Additional Notes

About speed-of-light navigation

Space travel matching the speed of light goes at a rate of 300,000 km per second. Even the best techniques of modern science can only manage 30 km per second, just 1/10,000 the speed of light. However, the distance between stars is so great that it would take several hundred to several thousand years to fly between them, even at the speed of light.

Jump Navigation (also called Leap Navigation or Warp Navigation)

This method of travel is much faster than the speed of light, but in Einstein’s Theory of Relativity it is proven that nothing can travel faster than light. However, expressions like “traveling at 5 times the speed of light” or “current velocity 10 times the speed of light” are heard in non-scientific circles. The bending, folding, or distorting of space are used in fiction. This is a space warp. We will use terms like, “go to warp navigation” and “OK, captain!”


Continue to Yamato Origins Part 5: Plan book by Eiichi Yamamoto

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