Star Trek: 10 Secrets Of USS Voyager You Need To Know
2. The Engines Couldn't Handle The Journey
While it was stated in countless episodes of Star Trek: Voyager that the journey to the Alpha Quadrant would take approximately 75 years, this number was apparently totally wrong.
As acknowledged by the producers themselves, the 75 year trip from the Delta Quadrant to the Beta Quadrant (not the Alpha Quadrant) was a best case scenario assuming Voyager would be flying at her maximum speed of warp 9.6 for the entire journey. However, not only did Janeway and her crew continually stop to find resources like food, make contact with new aliens, explore interesting space phenomena, and just generally cause trouble wherever they went, Voyager's engines themselves were simply not designed to handle sustained flight.
According to the ship's designers, Rick Sternbach and Michael Okuda, the trip home would have actually taken between 200 and 400 years. This much more dire travel time is stated in Star Trek: Voyager's behind-the-scenes technical manual and accounted for the ship's periodic need for refueling and maintenance as well as for the very practical need to occasionally cool off those environmentally friendly warp engines.