The effects of gravity on the crystal nucleation of heavy metal fluori
de fibers have been studied in preliminary experiments utilizing NASA'
s KC-135 reduced gravity aircraft and a microgravity sounding rocket f
light. Commercially produced fibers were heated to the crystallization
temperature in normal and reduced gravity. The fibers processed in no
rmal gravity showed complete crystallization while the fibers processe
d in reduced gravity did not show signs of crystallization.