The Lewis and Clark was the first human spaceship to use an atomic-powered engine to achieve constant acceleration. It was built in top secret by converting a former American orbital space station and was sent to the asteroid belt in 1963. Lieutenant General Charles Healey was its first commander. Walter Stone and Mickey Flynn were its original pilots; they were joined by Glen Johnson, who more or less stowed away aboard the ship.
The ship was named for Captain Meriwether Lewis and Lieutenant William Clark, the leaders of an expeditionsent by President Thomas Jefferson to explore newly acquired United States territories in the early nineteenth century.