The Three Worlds Aerospace Corporation model Super-Duo. An improved model of the Duo, the Super-Duo was a huge commercial success, being purchased by many families as a second flyer and by many people who could not afford something bigger and more glamorous. The Super-Duo was designed from the outset to be relatively cheap to buy and very cheap to operate, requiring much less frequent servicing than most flyers and costing less to purchase too. The compact size also made it easier to accommodate. Although the battery size was modest the craft's lightweight structure meant that it had a five hour endurance on a full charge, which enabled it to have a considerable range. The gravity manipulator chamber was also easy for a technician to balance and align, making it popular with service technicians as well as owners. The Super-Duo was first produced in 2240 and was in continuous production for the next 227 years. As time and technology improved the vehicle was given regular upgrades, most of which could be be retro-fitted to earlier models. It always remained one of the cheapest two-seat flyers on the market and was always the cheapest to maintain which surely contributed to its huge success. Having fun designing these. If the gravity manipulation tech actually existed these would be what people would own instead of cars from about the year 2100 onwards. No piloting skills required, get in, tell it where you want to go and sit back and enjoy the ride. Being able to go into low orbit means it could take you from any point on Earth to any other in about a hundred minutes, allowing for climb-to-orbit and re-entry.