With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Little Boy was dropped by a commander of the United States Army Air Forces.
text_B: Locomotion in space includes any variety of actions or methods used to move one 's body through an environment with microgravity conditions .. Locomotion in these conditions is different from locomotion in Earth 's gravity .. There are many factors that contribute to these differences , and they are crucial when researching long-term survival of humans in space .
not_related.