Fireball XL5:
Invasion Earth
Season 1, Episode 31
Original Transmission 26 May 1963
Written by Dennis Spooner
Directed by Alan Pattillo
Production Order
The Day The Earth Froze
Ghosts Of Space
Broadcast Order
A Day In The Life Of a Space General
Faster Than Light

Invasion Earth is the 34th produced episode and the 32nd broadcast episode of the series Fireball XL5.


A strange cloud of smoke heads towards earth jamming all communication in Space City. It is up to Steve Zodiac to save earth from an invasion.


At Space City, heavy interference has knocked out most communication. Commander Zero and Lieutenant Ninety believe it’s caused by a cloud of gas in space that is getting closer to earth.

So they send in Fireball XL18 to disperse the cloud. As it gets closer, a strange voice is heard over XL18’s radio. XL18 enters the cloud, but suddenly explodes.

They then send Fireball XL24 to investigate. Commander Zero instructs the pilot not to get to close to cloud.

On another planet, Dr Venus is inoculating everyone at a base for Restameisa. A space disease that is spreading fast around space quickly. Once she is done, they head back to earth in Fireball XL5

Soon XL24 arrives at the cloud. The pilot gets the interceptor missiles out, ready and armed. Once again, the strange voice is heard over the radio. XL24 flies above the cloud. Suddenly it explodes.

On board XL5, Steve, The Professor and Venus have just watched XL24 be destroyed on the monitor. However, Steve doesn’t think that XL24 exploded for no apparent reason. He is quite sure something came out of the cloud.

They play the recording of it in slow motion. They see that a missile was fired at XL24 from out of the cloud destroying it. Because of this they are able to work out that there must be some kind of invasion fleet in the cloud.

Soon the cloud reaches earth, all communications are down and all the ray guns are disabled. Suddenly a fleet of space ships come down from the clouds and land around Space City. Two aliens make there way to the control room where they order Commander Zero to inform Fireball XL5 it’s ok to land. However, Commander Zero refuses. So the leader of the aliens gives him five seconds to make up his mind or he’ll shoot him.

Unexpectedly, Zero’s son (Johnathan ) enters the room. The aliens get Johnathan at gunpoint and force Zero to call XL5 and bring the ship down.

When Steve receives the orders he decides to go down and land knowing there’s not much they can do in space.

As XL5 begins the descent, the alien leader orders three missiles ready to fire. He begins the countdown. 10, 9, 8, 7, 6, 5, 4, 3, 2…1. Suddenly the Leader collapses.

It turns out that the aliens fainted because they caught Rystamesia, and so Venus suggests the others should be inoculated. Zero, however, suggests Ninety goes first, whilst he makes a break for it.

Regular CastEdit

Guest Voice CastEdit


  • Fireball XL18
  • Fireball XL24



  • In one shot, the XL18 Pilot is sitting in the right seat of the cockpit. In the next shot he has changed to the left seat.
  • If all communications have failed at Space City, then how come Commander Zero is able to contact Fireball XL5?