Updated: February 10, 2024

Major Don West is the pilot of the Jupiter-2. He was an officer in the United States Space Corps, and the air force. In an emergency, if something went wrong with the crafts automatic guidance system, he would be awakened from suspended animation to correct the problem. Don's military training has proved useful in resolving a number of tense moments. He is also adept at overpowering aliens with his strength, but despite this he has suffered injuries more often than anyone else in the crew. This may be partly due to the fact that he seems to have a susceptibility to concussions which makes it easier for him to fall unconscious if he hits his head hard. He once described his roles on the ship as astronaut, plumber, gas station attendant, fixer-upper and radio announcer. He was the only one who could pilot the Jupiter-2, though he seemingly later taught this ability to the other members of the crew. The original pilot introduced him as Dr. Donald West from the Center for Radio Astronomy who had produced a groundbreaking theory on the habitability of other planets in 1996. The novel follows this, describing him as a young scientist who was onboard the Jupiter-2 when it was lost.

Don has a varied rapport with the others on the mission. If it were up to Don, Dr. Smith would be left behind. Don respects John Robinson, but sometimes questions his judgement. He is obviously attracted to Judy, but his feelings for her are often implied rather than overt. Despite being a top-notch pilot, Don seems to have a problem avoiding crash landings. His nickname was "Crash West" Don often reveals a violent temper that must be occasionally reined in by Prof. Robinson. During the latter part of the series, Don showed signs of mental instability. Killing Don off in the unmade 4th season was considered, according to fan rumour. In "Voyage to the Bottom of the Soul", a Lost in Space Graphic novel, he marries Judy Robinson "The Epilouge", a special feature on the 2015 Blu Ray release, confirms this. They had a son, Joshua Robinson West.