The Cargo-one is the older of these two designs. Carrying only fuel, the ship offered the fastest way of ferrying people or lightweight cargo between the Earth and Mars spheres. In response to growing demand, Solar Cradle Structures designed the smaller Shuttle-one, primarily a personnel transporter. Both vessels come in a variety of configurations, ranging from pure bulk cargo freighters over personnel transporters to recreational vehicles or mobile offices. Neither vessel is built for in-atmosphere flight, but separate launch vehicles exist to allow the ships to land on or depart from planetary surfaces without having to spend their own fuel. Some stats (Cargo vs Shuttle) : Cargo space : 1200 m3 multipurpose + 400 m3 fuel vs 40 m3 + 90 m3 fuel. Power : 2500 kW vs 1000 kW generator for engines, both with basic passive ramscoop and a 50 kW generator for ship systems. Class 2 optimised hybrid-propellant engines : 8x 180 kN vs 4x 130 kN. Class F1 magnetoplasmadynamic field drives : 1200kW 2x 150 kN vs 400kW 2x 50 kN. Top speed fully fueled, no cargo and using all fuel start-stop : 3.8 vs 6.5 days to the AU. Follow the story at http://nulll.net/xera/