Add another module to detect the presence of oxygen in the atmosphere, and they had made a jet engine. When they added a module to allow fuel to flow into and out of the engine, the team had a liquid fuel rocket. With a 3D model and a few modules it was easy to create a solid fuel rocket. And, more importantly, it had a list of modules, which is the code that we would attach to them.'

'So it became in essence just a container. 'For instance … a discrete object that you can place in the game we broke down to just a visual model, its basic attachment module, physics and how the destruction and persistence is handled. 'We focused on breaking down all of our systems into smaller chunks,' Jenkins said. Instead of creating a unique, complex set of code for each type of component, they instead programmed each of the essential functions the component would perform and bundled those functions, or modules, together. The solution the team settled on was what they call a 'modular design.' Individual ship components, like engines, were broken down into their essential functions. They decided to take the simplest elements of the game, the actual rocket components themselves, and rebuild them from scratch. While preparing the game for sales through Steam they found they were spending just as much time fixing buggy code as they were creating new content. We didn’t really do a lot of planning ahead.' And really the next update could have been the last. 'We were not sure if it would succeed or not. 'The game was, in some ways, an experiment,' Jenkins said, referring to its origins as a side project for a Mexican marketing company.

Technical artist Chad Jenkins, in a presentation at this year’s Game Developer’s Conference, says that the team came to a crossroads in their development around the time they were invited to be part of the Steam marketplace in 2013. The initial development was incredibly fast, and the code was buggy. Players are given a clean slate, a collection of parts and an entire universe to explore. Simply pick a piece, move it to the right position and it snaps into place. The allure of the game comes from the simple mechanic used for building. The space exploration simulation invites players to build and fly rockets and other types of craft. The vast complexity found in the latest version of Kerbal Space Program is the result of the team’s willingness to throw out the hard work they’d previously done and start again.

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