The background to the story is that Aldrin was an elder at his Presbyterian Church in Texas during this period in his life, and knowing that he would soon be doing something unprecedented in human history, he felt he should mark the occasion somehow, and he asked his minister to help him. And so the minister consecrated a communion wafer and a small vial of communion wine. And Buzz Aldrin took them with him out of the Earth's orbit and on to the surface of the moon.
Read the article, its cool!  http://www.snopes.com/glurge/communion.asp