Mars Direct

The Mars Direct mission sequence.

Mars Direct is a proposed mission architecture, developed by Robert Zubrin and David Baker at Martin Marieta in 1990. Mars Direct uses a reduced set of technologies to land a small crew on Mars for a long duration science mission. This plan was summarized in the book, The Case For Mars, written by Robert Zubrin and Richard Wagner. Mars Direct was innovative for its use of in situ resource utilization (ISRU) and for its use of direct launch from Earth to Mars without orbital construction or Mars orbit rendezvous. Mars Direct relies on separate outbound and return vehicles, and a pipelined mission architecture for improved redundancy. It has inspired several later proposed mission plans, including NASA's Design Reference Mission.

Terminology

There has only ever been one one Mars Direct proposed mission architecture. However, in some circles "Mars Direct" has become shorthand for any mars mission profile which reduces payloads and costs with ISRU and direct launch trajectories, including variants that make use of nuclear thermal rockets and NASA's Design Reference Mission. The term "Mars Semi-Direct" was coined by Robert Zubrin to describe otherwise similar mission architectures that employ of Mars orbit rendezvous.

This wiki article is about the original proposed mission architecture, and includes secondary discussion of only those variants described by the original authors, Robert Zubrin and David Baker.

Cost

In The Case for Mars, Robert Zubrin estimated the cost of development and operation of 3 missions at $20 - $30 billion.

Mass Figures

On page 93 of The Case For Mars Zubrin gives the following numbers for the masses of each component. These are the masses to Mars's surface and not to orbit. Basically all of the mass is assigned either to the Hab or to the ERV.

Hab

Total Mass: 25.2 Tonnes

Hab Structure: 5.0 Tonnes
Life Support System: 3.0 Tonnes
Consumables: 7.0 Tonnes consisting of (TCFM page 92):
- Oxygen: 160 kg total (1 kg/man*day at 80% reuse)
- Dry Food: 1600 kg total (.5 kg/man*day at 0% reuse)
- Whole Food: 3200 kg total (1 kg/man*day at 0% reuse)
- Potable Water: 0 kg total [?] (4 kg/man*day at 80% reuse)
- Wash Water: 2080 kg total (26 kg/man*day at 90% reuse)
Electric Power (5 kWe solar): 1 tonne
Reaction Control System: .5 tonnes
Communications and information management: .2 tonnes
Lab Equipment: .5 tonnes
Crew: .4 tonnes
EVA Suits (4): .4 tonnes
Furniture and Interior: 1 tonne
Open Rovers (2): .8 tonnes
Pressurized Rover: 1.4 tonnes
Field Science Equipment: .5 tonnes
Spares and Margin (16%): 3.5 tonnes