Some 250 spectators cheered as a space shuttle main engine roared to life and sent smoke across the Marshall Space Flight Center during a 45-second test firing.

"Anything that goes the full duration looks and sounds like a good test to me," center director J.R. Thompson said after Saturday's test at the northern Alabama base.Thompson said the benefits of the test firings should be seen by the mid-1990s when NASA plans to begin sending pieces of its space station into orbit aboard the space shuttle.

NASA engineers fired the engine as part of a series of tests to make the main engines for the space shuttle more effective.