Robert Joseph "Bob" Cenker (born November 5, 1948) is an American aerospace and electrical engineer, aerospace systems consultant, and former astronaut. Cenker worked for 18 years at RCA Astro-Electronics, and its successor company GE Astro Space, on a variety of spacecraft projects. He spent most of his career working on commercial communications satellites, including the Satcom, Spacenet and GStar programs. In January 1986, Cenker was a crew member on the twenty-fourth mission of NASA's Space Shuttle program, the seventh flight of Space Shuttle Columbia, designated as mission STS-61-C. Cenker served as a Payload Specialist, representing RCA Astro-Electronics. This mission was the final flight before the Challenger disaster, which caused the Space Shuttle program to be suspended until 1988, and impacted NASA's Payload Specialist program for even longer. As a result, Cenker's mission was called "The End of Innocence" for the Shuttle program. Following the completion of his Shuttle mission, Cenker returned to work in the commercial aerospace field. Since his flight, he has made numerous public appearances representing NASA and the Shuttle program, in the United States, as well as internationally.