(Work in progress...) The unaired pilot for Lost In Space has many differences and many similarities to "The Reluctant Stowaway", the aired pilot. The most glaring difference is the lack of the Robot and Dr. Smith. As for similarities, much of the footage from the Lost In Space unaired pilot is used in other first season episodes, including "The Reluctant Stowaway".
Watch Lost In Space No Place To Hide Online
The Robinson family (without the later-to-be-added Robot B-9 and Dr. Smith characters) rockets into outer space, only to crash-land onto a desert planet.