1. AS BLIMP RISES, the helium in the envelope expands, increasing the internal pressure. The ballonets -- air bags inside the blimp -- are deflated to compensate.  2. BLIMP CRUISES at 1,000 to 3,000 feet going 35 mph. The higher the blimp rises, the more air that must be released from the ballonets to compensate. The blimp can rise as high as 10,000 feet.  3. AS BLIMP DESCENDS, envelope pressure drops and ballonets are inflated -- air scoops behind the turboprop engines funnel the air pushed out of the engines into the ballonets. The retractable landing gear is released.  4. MEMBERS OF THE GROUND CREW grab the two ropes attached to the nose cone to help secure the blimp. Once it is close enough to the ground, other members grab the railing on both sides of the gondola. The blimp is docked to a portable moor.