Design Reference Mission 4 NTR

American manned Mars expedition. Study 1998. The design reference mission 4.0 took into account all of the changes in payload masses as a result of further study of individual elements.

Overall mass required in low earth orbit was reduced only slightly, by 2.5%. The use of NTR bimodal propulsion, with a single nuclear reactor that provided both propulsion and electrical power during space operations, in lieu of a separate power source, was made baseline. Cryo/aerobrake and solar electric options were retained.

Design Reference Mission Bimodal Mission Summary:

• Summary: Refine DRM 3.0; NTR Bimodal "all-propulsive" option; source data from Borowski NTR
• Propulsion: Nuclear thermal
• Braking at Mars: aerodynamic
• Mission Type: conjunction
• Split or All-Up: split
• ISRU: ISRU
• Launch Year: 2011
• Crew: 6
• Mars Surface payload-metric tons: 33
• Outbound time-days: 180
• Mars Stay Time-days: 570
• Return Time-days: 150
• Total Mission Time-days: 900
• Total Payload Required in Low Earth Orbit-metric tons: 400
• Total Propellant Required-metric tons: 180
• Propellant Fraction: 0.45
• Mass per crew-metric tons: 66
• Launch Vehicle Payload to LEO-metric tons: 75
• Number of Launches Required to Assemble Payload in Low Earth Orbit: 6
• Launch Vehicle: Magnum