Sherwood Clark Spring is a retired United States Army colonel and former NASA astronaut. Spring is married with two children. He is the father of United States Olympian Justin Spring. Sherwood Spring has logged 165 hours in space, 12 of which were spent conducting spacewalks. Spring has also accumulated 3,500 hours in 25 different military and civilian aircraft; over 1,500 of those hours were spent in jet aircraft.

NASA Astronaut Group 9 was a group of 19 NASA astronauts announced on May 29, 1980, and completed their training by 1981. This group was selected to supplement the 35 astronauts that had been selected in 1978, and marked the first time that non-Americans were trained as mission specialists with the selections of ESA astronauts Claude Nicollier and Wubbo Ockels. In keeping with the previous group, astronaut candidates were divided into pilots and mission specialists, with eight pilots, eleven mission specialists, and two international mission specialists within the group.