Angus Allan and illustrated by Mike Noble; running in TV Century 21 (later renamed TV21) from 21 Jan. 1967 to 21 Sept. 1968. A model of the Zero-X was included in the "Project SWORD" line of toys marketed by Century 21 Merchandising. Filming models Zero-X was designed by Derek Meddings, whose original drawing named the craft "ZX 26". AP Films commissioned Slough-based company Mastermodels to make two scale filming models. The larger of the pair, which was built at a cost of £2,500 (), was long and weighed . The puppet set design of the cockpit was inspired by the interiors of Concorde, a prototype of which the crew viewed at Filton Airfield. In 2012, the original MEV filming model, minus the cockpit canopy, was acquired by prop restoration company The Prop Gallery, which commissioned the still-trading Mastermodels to refurbish the miniature that it had built 46 years earlier. Critical response According to spaceflight historian Jack Hagerty, the way in which the MEV is deployed from the mothership was inspired by both the titular spacecraft of the Andersons' earlier puppet series Fireball XL5 (whose cockpit section breaks off to form a lander, Fireball Junior) and the modular construction of the real-life Apollo spacecraft. He also states that the name "MEV" is based on "LEM" (Lunar Excursion Module), the original designation for the Apollo Lunar Module. Among other observations, Hagerty questions the names given for some of Zero-Xs components in Thunderbirds Are Go, stating that the craft's so-called nose cone "looks nothing like a cone" and that its lifting bodies do not meet the technical definition a lifting body. He also regards the brevity of the Martian landing as a flaw in the film's plot: "After spending, presumably, many years and billions of dollars mounting this expedition to Mars, all they get for their effort is a couple of hours driving around on the surface." However, he calls the destruction of the Zero-X Mark II "one of the most spectacular crash sequences ever filmed". Stephen La Rivière, in his book Filmed in Supermarionation: A History of the Future, calls Zero-X "the star of Thunderbirds Are Go", praising Meddings' design and acknowledging its commercial nature: "... cynics would suggest that the various detachable segments (wings and nose cone) had less to do with the storyline and more to do with potential toy manufacturing!" Glenn Erickson of the website DVD Talk considers Zero-X