In the first season of Lost in Space, the Robinsons encounter only one earth ship besides their own Jupiter 2. This occurs in the episode “Welcome Stranger” where Jim Hapgood lands on Priplanus in the Mercury- or Gemini- like space capsule he has been travelling in for a dozen years or more. Other members of this wiki have raised the question of whether or not Hapgood’s ship was only a landing vehicle; it is rather difficult to imagine such a small ship being able to hold the food and air (or even equipment to produce or recycle those) necessary to a voyage of any duration. “The Raft” features a knock-up capsule the Robinsons build using their atomic reactor core, but it does not manage to reach escape velocity and crashes back onto Priplanus.