Charles David "Charlie" Walker (born August 29, 1948) is an American engineer and astronaut who flew on three Space Shuttle missions in 1984 and 1985 as a Payload Specialist for the McDonnell Douglas Corporation.

His recreational interests include photography, running, hiking, scuba diving, reading, collecting books on space, and bonsai.

McDonnell Douglas' main partner was Ortho Pharmaceutical, which hoped to manufacture large amounts of purified erythropoietin in space.

[3] From 1979 to 1986, Walker was chief test engineer and payload specialist for the McDonnell Douglas EOS commercialization project, having told company management that he was interested in flying in space if possible.

His contributions to the program included engineering planning, design and development, product research, and space flight and evaluation of the CFES device.

He served on the AIAA steering committee formulating the strategic plan for NASA's office of Commercial Programs.

Walker retired in 2005 as the Director for NASA Systems Government Relations with the Washington D.C. Operations office of The Boeing Company.

Although Europeans were training for Spacelab Payload Specialist duties, Walker remained a McDonnell Douglas employee, and commuted between company headquarters in St. Louis, Missouri and the Johnson Space Center in Houston, Texas.

[2][6] Although Walker believed at the time that 41-D would be his only flight,[7] he also accompanied the CFES equipment on STS-51-D, and STS-61-B, accumulating 20 days of experience in space and traveling 8.2 million miles.

Aboard these Space Shuttle missions Walker also performed early protein crystal growth experiments and participated as a test subject in numerous medical studies.