Question: who launched the first spacecraft to reach the lunar surface
[{'answer': 'Soviet Union', 'provenance': [{'wikipedia_id': '81993', 'title': 'Luna 2', 'start_paragraph_id': 1, 'start_character': 129, 'end_paragraph_id': 1, 'end_character': 141, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]