on monday, january 22, 1968, a 16-ton unmanned lunar module surrounded by a protective shield stood on top of a two-stage saturn 1-b rocket called apollo 5. this flight was made to do two important tests. one was to check separating stage from main rocket. the second was to check test firing of the descent engine, but this mission did not succeed. the apollo 5 test ended after eight hours, and the lm remained in earth orbit. it eventually dropped into the atmosphere and burned up.