The Mega Rover was conceived to support a crew of six over thousands of kilometers of traverses. Variants had masses as great as 45 metric tons, exclusive of the descent and landing system. The large size of the rover was designed to allow a majority of the exploration to be conducted without leaving the rover, thus minimizing the dust issue.

This large mass in a single launch vehicle would require something at least twice as large as a Saturn V. The Mega Rover was 16 m long, 4.5 m wide, and 10 m high. It consisted of a large pressurized module containing about 650 m3 of internal volume. A power trailer was pulled behind the rover, providing electricity to drive four wheels of 2.5 m diameter. A diving bell style airlock provided access to the surface for a crew of six that would conduct traverses of up to several thousand kilometers.

Crew Size: 6. Length: 16.00 m (52.00 ft). Basic Diameter: 4.50 m (14.70 ft). Maximum Diameter: 10.00 m (32.00 ft). Mass: 45,000 kg (99,000 lb).

• Zakrajsek, James J; McKissock, David B; Woytach, Jeffrey M; Zakrajsek, June F; Oswald, Fred B; McEntire, Kelly J; Hill, Gerald M; Abel, Phillip; Eichenberg, Dennis J; and Goodnight, Thomas W, Exploration Rover Concepts and Development Challenges, NASA/TM-2005-213555 / AIAA-2005-2525, March 2005..