BENGALURU/WASHINGTON, Aug 23 (Reuters) - India's space agency landed a spacecraft on the moon's south pole on Wednesday, a mission that will advance the country's space ambitions and expand knowledge of lunar ice, potentially one of the moon's most valuable resources. Here's what's known about the presence of frozen water on the moon - and why space agencies and private companies see it as a key to a moon colony, lunar mining and potential missions to Mars. India's much-awaited moon mission Chandrayaan-3 has been scheduled for launch on July 14, 2023. The Soviet Union, the United States, and China are...