Plesetsk Cosmodrome on June 29, 1982. Cospas-Sarsat began tracking the two original types of distress beacons, EPIRBs and ELTs, in September, 1982. The first persons were rescued with the assistance of Cospas-Sarsat when the distress signal from a small plane was relayed by the COSPAS-1 satellite to a then-experimental ground station in Ottawa, Ontario, Canada. The story has been related by the plane's pilot, Jonathan Ziegelheim, who rescue authorities judged would probably have died of his injuries if it were not for Cospas-Sarsat. Prior to the founding of Cospas-Sarsat, the civilian aviation community had already been using the 121.5 MHz frequency for distress, while the military aviation community utilized 243.0 MHz as the primary distress frequency with the 121.5 MHz frequency as an alternate. In each case, detection of the distress signal relied on reception by aircraft passing nearby, and localization of the signal was done with Earth-based direction finding equipment. Satellites made it possible to expand this "local" search paradigm into a global capability. Each of the four founding Party States took responsibility for one of the major tasks in the project. The United States (with project leadership from NASA's Goddard Space Flight Center in Greenbelt, MD, USA) directed Datron Systems in Chatsworth, CA, USA to design and build LUT ground stations to receive the downlink from the satellites. At Datron, a team designed a LUT with five horn antennas, and Jeffrey Pawlan designed the downconverter and the specialized monopulse receiver capable of locking onto the downlink from the satellites. France and Canada were responsible for the data generation and decoding. They designed the computer that determined the approximate position of the beacon from the Doppler shift of the beacon's signal caused by the relative motion of the beacon and the receiving satellite. The former Soviet Union was responsible for the design and construction of the first satellite to be launched. Engineers from all four countries met in Moscow in February 1982 to successfully test the operational functionality of all of the equipment together in the same laboratory. The Party States led development of the 406-MHz marine EPIRB, that used a digital messaging scheme, for detection by the system. The EPIRB was seen as a key advancement in SAR technology in the perilous maritime environment. The digital message allowed the beacon and its associated vessel to be uniquely identified. Early in its history, the Cospas-Sarsat system was engineered to