to the back tip such that the ski rests at a slight angle of 0.05º. Viscous forces trap a thin film of air in the converging gap between the ski and the tube wall. The air beneath the ski becomes pressurized which alters the flow field to satisfy fundamental laws of mass, momentum, and energy conservation. The resultant elevated pressure beneath the ski relative to the ambient atmosphere provides a net lifting force that is sufficient to support a portion of the capsule’s weight. However, the pressure field generated by aerodynamics is not sufficient to support the entire weight of the vehicle. At lower speeds, very little lift can be generated by aerodynamic mechanisms. Temperature and density in the fluid film begin to rise more rapidly than pressure at high speeds, thus lift ceases to increase as the capsule accelerates into the transonic regime. Lift is supplemented by injecting highly pressurized air into the gap. By applying an externally supplied pressure, a favorable pressure distribution is established beneath the bearing and sufficient lift is generated to support the capsule. This system is known as an external pressure (EP) bearing and it is effective when the capsule is stationary or moving at very high speeds. At nominal weight and g-loading, a capsule on the Hyperloop will require air injection beneath the ski at a rate of 0.44 lb/s (0.2 kg/s) at 1.4 psi (9.4 kPa) for the passenger capsule. The air is introduced via a network of grooves in the bearing’s bottom surface and is sourced directly from the high pressure air reservoir onboard the capsule. The aerodynamically and externally pressurized film beneath the skis will generate a drag force on the capsule. The drag may be computed by recognizing that fluid velocity in the flow field is driven by both the motion of the tube wall relative to the ski and by a pressure gradient, which is typically referred to as a Couette-Poiseuille flow. Such flows are well understood, and the resultant drag can be computed analytically (as done in this alpha study) and improved and/or validated by computational methods. The predicted total drag generated by the 28 air bearings at a capsule speed of 760 mph (1,220 kph) is 31 lbf (140 N), resulting in a 64 hp (48 kW) power loss. The passenger capsule air bearing system weight is expected to be about 6,200 lb (2,800 kg) including the compressors, air tank, plumbing, suspension, and bearing surfaces. The overall cost of the air bearing components is targeted to be no more than $475,000. Hyperloop Passenger Plus Vehicle Capsule The passenger plus vehicle version of the Hyperloop capsule places more aggressive lifting requirements on the air bearings, but the expanded diameter of the tube provides a greater surface area for lift generation. For this version, an extra 12 in. (30 cm) of width would be added to each bearing. The nominal