Luna 5 was an unmanned Soviet space probe launched for lunar investigation. On May 10, the spacecraft began spinning around its axis due to a problem in a gyroscope in the guidance system unit. A subsequent attempt to fire the main engine failed because of a ground control error, and Luna 5 impacted the lunar surface. Though it failed to soft-land—Luna 9 would do so a year later—Luna 5 was the second Soviet lunar probe to land on the moon. What was the first? Discuss (http://forum.thefreedictionary.com/postst57998_-i-Luna-5--i--Crashes-on-the-Moon--1965-.aspx)