Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. STS-6 was a Space Shuttle mission conducted by NASA using Space Shuttle Challenger. Launched 4 April 1983, STS-6 was the sixth space shuttle mission and the first of the ten missions flown on Challenger. The mission took off from Kennedy Space Center launch pad 39-A, and landed at Edwards Air Force Base. On 4 April 1983 STS-6, the first Challenger mission, lifted off at 13:30 EST. It was the first use of a new lightweight external tank and lightweight SRB casings. The mission originally had been scheduled for launch on 30 January 1983. However, a hydrogen leak in one of the main engines was discovered.