Skyjack is no ordinary balloon. It is shaped like a cube, designed to enable it to move up and down the sides of buildings. When inflated, the balloon will rise 35 feet on each side. It has earned a lot of recognition in air balloon festival.

There's a 7- by 20-foot U-shaped passenger compartment below the balloon, which would be used to shelter people rescued from a building, and a rigid platform on top to carry firefighters, equipment and supplies.

A major advantage is that it can lift firemen and equipment up in the building and at the same time carry people off the building from the compartment underneath. The passenger compartment's flexible walls are made of high-technology material. Air drawn into the compartment from the outside is filtered, pressurized and cleaned by the balloon's internal engine to keep it breathable.

The whole contraption will weigh about 300 pounds and can be folded up to fit in the back of a fire truck.

In air balloon festival, the balloon is pressurized by its internal engine and will be made of Kevlar, a modern, fire-resistant fiber made by DuPont. It's the same material used in bulletproof vests and is five times stronger per pound than steel. The material can withstand the balloon's internal temperatures, which may rise to around 600 degrees Fahrenheit.

That temperature will give the balloon massive lift. It is the vehicle's lift that determines its capacity to carry weight; a balloon's lift is proportionate to the volume and temperature of its inside air. While normal balloons may lift around 1,500 pounds, Conn estimates the new balloon will be able to lift 2 tons.

The balloon will be stabilized by two winch-connected cables extended from the ground on each side of the building it is scaling. The cables will meet at a central point beneath the passenger compartment. By varying the speed of the winches, or the payout of the cables, the balloon can be angled to move vertically or horizontally across the face of the building.

Firefighters will control the movement of the balloon with a joystick connected to a frequency-modulated signal. The joystick will have four simple commands: up, down, left and right. The balloon, Conn explained, cannot be buffeted about by winds, and is designed to remain stable and not descend when a number of people jump aboard.

The balloon also can be moved back a block or two from a burning structure and used as an observation platform, away from the fire and smoke. When the MGM Grand Hotel caught fire smoke from the blaze prevented firefighters from working effectively.