The UNSS Lewis and Clark, also known as the USS Lewis & Clark, was a 21st century spaceship launched from Earth, a United Nations Space Probe mission commanded by Colonel Shaun Geoffrey Christopher. Christopher's mission on the Aventeur-class sublight explorer Lewis and Clark was the first manned flight to Saturn on reference stardate 0/20. The ship was equipped with a revolutionary impulse engine, which reduced its travel time to Saturn to a matter of months. (TOS reference: Spaceflight Chronology, TOS novel: The Rings of Time)
The Lewis and Clark was equipped with a science laboratory, individual cabins as quarters for each of the three crew members, and a cargo bay filled with food, supplies, and mementos from Earth. (TOS novel: The Rings of Time)