The objective of the Pad Personnel Locator project is to design and develop a radio frequency (RF) transponder-based system using RF identification tags. There is a requirement to monitor the location of personnel within the launch pad perimeter after cryotanking begins during Shuttle countdown for launch. These personnel include the astronauts, closeout crew, ice team, and, if necessary, rescue personnel. Monitoring these personnel is currently performed using a combination of television camera monitoring and radio link verbal communication. In the event of an emergency at the launch pad, location of injured personnel could be difficult since smoke and deluge water could obscure the view of the television cameras. The ability to accurately determine the location of injured personnel would allow rescue crews to immediately reach the desired location, minimizing their own exposure to the haz-ardous conditions present at the launch pad.
The approach selected to track and locate personnel as they move through the launch pads is based on the use of radio-frequency-activated identification (RF-ID) tags. These RF-ID tags do not require any external power source for operation, thus making their installation easy and inexpensive. Each RF-ID tag will contain information that will uniquely determine its position at the launch pad. Personnel working at the launch pad will be equipped with a transponder unit that will perform the following functions:
The RF-ID tags are designed to respond to a specific code. The tags will be placed along the launch pad structure in such a way that no two tags with the same code will be within the range of the interrogating unit. The interrogating unit will sequentially transmit all different codes (three or more) providing for enough time for a potential response for the correct tag within its range.