STS058-21-011 (24 Oct 1993) --- From the flight deck of the Earth-orbiting Space Shuttle Columbia, astronaut William S. McArthur talks to students on Earth. The mission specialist's activity was part of the Shuttle Amateur Radio Experiment (SAREX), a frequent payload on Shuttle missions which serves to enlighten students around the world on the topic of space travel. McArthur (call letters KC5ACR) is one of three licensed amateur radio operators on the seven-member flight.