On August 18, 1976, a 4-meter-high spacecraft called the Luna-24 touched down on the Mare Crisium, a flat plain in the moon’s northern hemisphere. Four days later, the Soviet-built vehicle returned to Earth, carrying a valuable sample of lunar soil, a portion of which Soviet scientists later swapped with colleagues at NASA in the name of international scientific cooperation.Almost 47 years later to the day, Russian engineers tried a near-repeat of that feat, seeking to land a craft packed with scientific instruments on the moon’s southern…
