Ernst Stuhlinger wrote this letter on May 6, 1970, to Sister Mary Jucunda, a nun who worked among the starving children of Kabwe, Zambia, in Africa, who questioned the value of space exploration. At the time Dr. Stuhlinger was Associate Director for Science at the Marshall Space Flight Center, in Huntsville, Alabama. Touched by Sister Mary’s concern and sincerity, his beliefs about the value of space exploration were expressed in his reply to Sister Mary. It remains, more than four decades later, an eloquent statement of the value of the space exploration endeavor. Born in Germany in 1913, Dr. Stuhlinger received a Ph.D. in physics from the University of Tuebingen in 1936. He was a member of the German rocket development team at Peenemünde, and came to the United States in 1946 to work for the U.S. Army at Fort Bliss, Texas. He moved to Huntsville in 1950 and continued working for the Army at Redstone Arsenal until the Marshall Space Flight Center was formed in 1960. Dr....