As well as providing space-rescue capability, Thunderbird 3 also serves as the primary supply vessel to the space station Thunderbird 5. The spaceship docks by entering nose-first through TB5's docking shaft, specifically-designed to match its diameter. Once the two vessels are tightly clamped together, and air-pressure is properly equalized, an airlock then provides access to the main control room aboard TB5.
- A: Hangar, Thunderbird 5.
- B: Sensors in ring on Thunderbird 3 guide nose into Docking port.
- C: Electro-magnets clamp the ring of TB3 forming an airtight seal. Air is then pumped into the hangar.
- D: Once the correct air pressure is achieved, TB3's airlock can be opened.
- E: Astronauts can proceed along Access Ramp to interior of Satellite.
- F: Airlock door to Inspection Platform.
Scott takes Alan to Thunderbird 5, to relieve John for a month's rest on Tracy Island.