Josh, keep in mind that the ATG AirShip Ground Vehicle design is not meant to fly, but uses Helium Bags to lift part of the weight off the original Track Sphere design which used 24 ball bearings to incase a sphere.
The new Track Sphere design uses Maglev Spherical Induction Motors http://www.airshiptg.org/Track%20Sphere%20Rotary%20Induction%20Motor%20(2).ppt
which eliminates the friction factor of the original 24 ball bearing approach. In the helium buoyancy design, the internal AirShip helium balloons experience an upward force that is equal to the weight of the air it displaces (the buoyant force on the balloon) minus its own weight. At sea level, air weighs about 0.078 pounds per cubic foot, so the upward buoyant force on a cubic foot of helium is about 0.078 pounds. A cubic foot of helium weighs only about 0.011 pounds. The difference between the upward buoyant force on the cubic foot of helium and the weight of the helium is the amount of extra weight that the helium can lift, which is about 0.067 pounds per cubic foot. To lift a 100 pound weight, you'll need about 1500 cubic feet of helium in the balloon. The AirShip Ground Vehicle has two strategically placed balloons, between the two they would have to lift about 50 pounds (750 cubic feet of helium) to relieve the original design. This is why we have moved to the improved Maglev SIM Track Sphere model: http://www.airshiptg.org/deloreanmaglevtracksphere.htm
