THE architects of the troubled Russian Mir space station could perhaps learn a lesson from Sheffield rocket technician Dr Tony Simons. His own spacecraft, based on an earlier 1960s design, has taken years to build and is still waiting for its reverse thrusters and a final decision on the paint scheme. Dr Simons' philosophy of waiting until all key components are properly tested and available has meant that his own craft has been in the construction stage since 1991.

But, once exactly the right Ribena bottle was found, it was only a matter of time before the launch of Dr Simons' spaceship was organised: it will possibly happen at next year's Babylon 5 Science Fiction convention in London.

"I'm very patient", he says. "I tend to work on Thunderbird 3 in my spare time at Easter or Christmas, but even then I've been known to wait until the third roll of sellotape has been finished before adding its centre to the rocket."

The inspiration came six years ago, when Blue Peter tried to cater to then colossal demand for Thunderbirds Tracy Island toys by offering a do-it-yourself version. Lifelong cardboard-and-sticky-tape enthusiast Tony Simons decided to go one better and build a Thunderbird 3. Now that model, with its margarine cartons, dowelling and papier mâché, as well as the crucial Ribena bottle nose cone, is nearing completion and Tony has already begun work on Thunderbird 2, "more of a challenge because of the shape", he reckons.

Tony has built models since the age of four. "Where my school friends might have played with train-sets, I would play with cardboard boxes and glue. I regularly got rolls of sellotape for Christmas presents."

The attraction of making scratch-built models, he said, is the challenge of "making something that looks good and is quite sophisticated out of rubbish."

The Apollo moon landings inspired him to make a scale model of the Saturn V rocket out of bottles and toilet rolls; and at the age of eleven his working model of a tower crane, made from cotton bobbins, cardboard and cornflakes boxes, was on display to fellow students for weeks at his junior school in Leicester.

"My parents must have been very tolerant," he recalls, "because the living room was often half full of cardboard boxes and models in various stages of completion."

Darth Vader was made later on during his student career, while he was studying linguistics and phonetics at Cambridge. "It was the late seventies, when Star Wars was popular for the first time and I decided to make a Darth Vader mask for a fancy-dress party."

Using a fraction of George Lucas' special effects budget, together with a colander, matchsticks, garden cane, a net curtain and Van Heusen shirt boxes "for a metallic effect", the costume caused quite a stir, although the heat inside and the wearer's inability to eat or drink anything have made Darth Vader an infrequent visitor on the Sheffield social circuit.

Tony admits that parallels could be found between his day job, as a computer science lecturer at Sheffield University and the designer of software components, and his model building activities. "It's making things fit and work together," he says, adding that the design-and-build philosophy he adopted meant that problems often had to be solved in a project after initial work had begun. "Like Supertram had to dig up the roads in different ways as the construction continued, after finding a new picture of Thunderbird 3 I had to trim all 32 cardboard fins to a different shape."