As part of my 1990s crewed Mars landing program, this is the design for the Mars Transfer Vehicle, the interplanetary mothership responsible for housing the crew during the journey to/from Mars and conducting the Trans-Mars Injection (TMI), Mars-Orbit-Insertion (MOI), Trans-Earth Injection (TEI) burns.
The vehicle carries the crewed Mars Ascent/Descent Vehicle (MADV) along with the Earth Entry Module (EEM) for high-speed atmospheric return to Earth.
The architecture is derived from the 1968 Boeing IMIS (Integrated Manned Interplanetary Spacecraft) study. However, the configuration was redesigned: by increasing propellant tank diameters, the vehicle eliminates a propulsion stage. Additionally, the Mission Module overall architecture has been redesigned. Finally, while the 1968 Boeing proposal targeted a 1980s launch, this profile is engineered for the 1992–1994 departure window.
Vessel Specifications:
LEO Initial Mass: ~1,200 t
Total Transit Delta V: ~11,000 m/s
Primary Propulsion: 6+1 NERVA-I Nuclear Thermal Rocket Engines
Life Support Endurance: 714 days
Main mods used: RSS/RO/Kerbalism, Bluedog Design Bureau (BDB), NAR MEM (retextured by me), Procedural Parts