Question

During the 1960s and 1970s, scientists designed a spacecraft based on nuclear propulsion, but it was never built. true

Answer 1

It is true that during the 1960s and 1970s, scientists designed a spacecraft based on nuclear propulsion, but it was never built.

Some of the examples of spacecrafts based on nuclear propulsion that were proposed are the following (in no particular order):

Project Daedalus

Project Orion

AIMStar

Project Longshot

External Pulsed Plasma Propulsion

ICAN-II