The Ultra Probe was the 8th Astro Probe.
A long-range explorer ship, the Ultra Probe was designed to take a crew of four - Command Pilot Captain Tony Cellini, Astrophysicist Doctor Darwin King, Medic Doctor Monique Bouchere and Radiation Expert Professor Juliet Mackie - to the planet Ultra, which had been discovered by Professor Victor Bergman in 1994. Due to its irregular orbit, the planet would only be in range of the Ultra Probe for a limited time.
Flight to Ultra
The Ultra Probe was launched from the orbital Spacedock on June 6 1996, and after a long journey arrived at Planet Ultra in February 1997. Once it achieved orbit, the craft lost radio contact with Moonbase Alpha. The probe's mission had been to make a manned landing on Ultra, but instead a small armada of derelict alien spacecraft were found in orbit round Ultra.
The Ultra Probe docked with one of the deserted alien spaceships; the crew's intention was to board the alien craft and explore it. However, as soon as they opened the airlock linking the two ships, a bizarre and deadly alien creature entered the Ultra Probe and killed all but one of the crew. The creature, apparently immune to laser fire, used a form of hypnotic inducement and its tentacles to grab the crew members and move them towards its "mouth" - a large hole at its base - and devour them. A few seconds later their smoldering skeletal corpses were subsequently spit out by the creature. The creature appeared able to affect the crew member's minds and weaken their resistance to being eaten alive until it was too late. Only Tony Cellini, the mission commander, was able to escape the creature. He managed to detach the command module of the Ultra Probe and perform a drastic manoeuvre that would get him back to Earth. He was found, barely alive, six months later by a rescue mission from Earth. 
When Cellini told his fantastic story to the authorities on Earth, they refused to believe him. The creature did not appear on videotape or mission records, nor did the vessels flight recorder pick up any lifeforms or conclusive evidence of a field of abandoned spacecraft. The conclusion was that Cellini had accidentally opened the airlock too early and his crewmates were sucked into space. Cellini was forced to undergo extensive psychiatric evaluation on Earth; Dr. Helena Russell was one of Cellini's evaluators. In her opinion Cellini had subconsciously fabricated his incredible story after suffering a nervous breakdown caused by accidentally killing his crew. However, Moonbase Alpha Commander John Koenig, a close friend of Cellini, believed his story and protected him in the years after the Ultra Probe disaster, securing a position for him on Moonbase.
The Ultra Probe was found five years later by the inhabitants of Moonbase Alpha, still docked to the alien ship, and the other derelict alien ships were also still nearby. Determined to redeem himself and prove that his story was true, Cellini stole an Eagle spacecraft and returned to the Ultra Probe; there he did battle with the creature using an axe from the equipment stand in the Eagle. He did succeed in wounding the creature, but it eventually devoured him after a fierce struggle. Commander Koenig then arrived and (apparently) succeeded in killing the creature with Cellini's axe; the creature vanished after leaving behind a pool of blood and the decomposed bodies of the four Ultra Probe crew members.
The Ultra Probe was a long-range explorer, its size suggested that it was designed to keep its crew in comfortable conditions for long periods. The Command module resembles the 'beak' of an Eagle, showing that many Earth ships share similar design characteristics. The command module also had seating for the mission specialists which would have been used if they had survived the attack of the creature, or if they had landed on Ultra as originally planned. The fact that Tony Cellini was able to dock an Eagle nosecone to where the command module once was located means that the Ultra Probe and Eagles are compatible in many respects.
- Space 1999 - Catacombs - Description of the Ultra Probe Main ship and the lifeboat.
- Space 1999 - Catacombs - Description of the Ultra Probe Interior.
- Space 1999 - Catacombs - Description of the Ultra Probe Mission profile.
- Martin Bowers Model World — Creator of the original model, along with other spacecraft from Space: 1999