A method and apparatus for investigating a chemical-based event inside a vehicle without significant delay. In one embodiment, the method begins by inserting a catheter having a dual balloon system into the large intestine of a patient. Payloads can be configured off-line from launch vehicle processing, thus making it possible to accommodate unique payloads while reducing wear and tear on the launch vehicle. The measurements may be used to derive network-performance related information such as cellular signal coverage areas, signal hole areas, and signal interference areas. The user may later recustomize the keyboard if desired. Accordingly, it is preferred that the tip of the blocking element has a variable angle, in order to match the angle of whichever leaf is adjacent.