Thunderbird 3 is International Rescue's single-stage-to-orbit (SSTO) space vehicle, designed for space rescue and maintaining the systems and crew of Thunderbird 5. Like all the Thunderbird machines, it was designed by Brains. Its main pilot is Alan Tracy, with his brother, Scott, usually acting as co-pilot.
Thunderbird 3 uses chemical rockets for lift-off and boost, an ion drive for propulsion while in space, and chemical retro-rockets for reverse-thrust in space. It could travel from Earth to within range of the Sun in 65 hours.
There are a number of levels within Thunderbird 3, accessed via a single-person lift. The primary cockpit is located at the uppermost level and contains the primary control console, seating for two and airlock access. A second room contains rescue equipment, including a control console for long-range transmissions such as a safety beam that can be used to trigger retros of distant space ships.
Its primary pilot is designated as Alan Tracy, although John is presumed to pilot Thunderbird 3 during space rescues when Alan is on satellite duty. (Both store their respective uniforms onboard, depending on who is "on call" at the moment; although John's is never actually seen there.)
The interior of Thunderbird 3 was originally decorated in beige, red and light grey colours. However, like all of the Thunderbirds, it underwent redecoration and refitting to a darker colour scheme and more comfortable and secure seating.
- Engines: 3 chemical rockets used for launch, landing, emergency boost, and orbit change; 3 ion-drive particle accelerators used in deep space; pitch and yaw rockets: 12 in middle ring for course corrections, 20 in nose and 24 at rear for attitude adjustments
- Emergency acceleration: 10 g
- Launch thrust: 4.5 million pounds
- Length: 287 feet
- Main body diameter: 23 feet
- Maximum sustained acceleration: 6g
- Nacelle span: 80 feet
- Power source: atomic fusion reactor
- Range: unlimited
- Standard acceleration: 1g
- Weight: 562 tons
- Main article: Thunderbird 3/Launch Sequence
- Main article: Thunderbird 3/Docking Procedure
- Main article: Thunderbird 3/Missions
- Main article: History of the Cutaway Drawings (Classic Thunderbirds)
- Throughout the series, each Tracy brother (excluding Gordon) is seen taking command of Thunderbird 3 on at least one occasion each. This is unique as it does not happen with any other Thunderbird in the fleet.
- Thunderbird 3's control room gets a complete redesign in Ricochet, link most other sets in season 2.
- Thunderbird 3 is the most rarely seen and used of the Thunderbird craft.
- This may have been because outer space rescue missions would have been too difficult to both write and film. Thunderbird 3 only had three rescue operations that were all relatively simple, and Thunderbird 2 was added to two of the missions to provide vital help. Consequently, co-creator Gerry Anderson had said he didn't find Thunderbird 3 exciting.
- Some shots of Thunderbird 3 taking off have a different font of the number 3, compared to shots of it flying through space.
- Despite being the pilot of Thunderbird 3 every other month, John Tracy was never seen piloting it in a rescue mission (he did guide TB3 in to dock with TB5, in The Mighty Atom). Only once was he ever seen seated on the settee, in the lounge - near the conclusion of Operation Crash-Dive.
- The original Thunderbird 3 is ultimately destroyed by the the Hood's henchmen in the TV21 comic, Brains Is Dead. The original Thunderbird 2 is also destroyed in the same way.