The space shuttle program began when the flew on april 12, 1981.

The answer to the question above is the Columbia.
The space shuttle program began when the Columbia flew on April 12, 1981. It was the first fully functional orbiter, which was built in Palmdale, California. It was delivered in Kennedy Space Center on March 25 1979. The launching of the space shuttle marked the 20th anniversary of Yuri Gagarin's space flight, which happened on April 12, 1961.

Cwould be the answer