A method, apparatus, article of manufacture, and a memory structure for providing access to an array-based data object to a client is disclosed. The system is based on improved understandings of human decision making under risk, and incorporates recent theoretical developments and computational tools. In position-adaptive bistatic mode, each low-altitude UAV estimates a new parameter denoted as the differential path length to adaptively implement self-adjustments in position. The door closes to seal the opening and prevents a flammable gaseous mixture in the interior space from leaking out of the interior space of the chamber.