New Mars

All too often, authors neglect the ’science’ in science fiction, but in Mars Frontier, Robert Stockman has written detailed appendices for each part of the novel. In this first appendix, Stockman discusses the technology and logistics of the journey from Earth to Mars.

Appendix to Part 1: Some Assumptions

Project Columbus is named for the explorer of the Americas and is conceived as an international effort to land people on Mars in order to set up an outpost from which the Red Planet can be explored and studied. The plan assumes:

1. The use of expendable commercial rockets capable of launching about 24 tonnes to low earth orbit such as the Ariane 5, Delta IV Large, and the Angara (this is the capacity of the Space Shuttle as well). Typically, the payload consists of 5 tonnes of ion engine tanks and propellant and 19 tonnes of cargo.
2. Solar powered ion-propulsion vehicles capable of lifting cargo from low earth orbit to the Lagrange Point between the Earth and Moon. Each vehicle has a dry mass of about 4 tonnes, has 1,200 square meters of high-efficiency solar panels able to make 400 kw of electricity, and with 5 tonnes of xenon propellant can lift 19 tonnes of payload to L1 in about six months.
3. Gateway Station, an occasionally staffed space station located at the Lagrange Point (L1) between the Earth and the Moon. Gateway consists of a single Interplantary hab or “Ihab,” a conical vehicle 13 meters long with a basal diameter of 6 meters. Its five stories contain 73 square meters of living space and can house four people (six in an emergency). An Ihab has a mass of 8 tonnes, plus an optional 2.4-tonne aeroshell and supplies.
4. Chemical propulsion from Gateway to the lunar surface and Mars using four-tonne (dry mass) LBVs (lunar-based vehicles), reusable stages able to hold up to 24 tonnes of liquid oxygen and hydrogen or 54 tonnes of liquid oxygen and methane.
5. Use of hydrogen and oxygen propellant derived from the permanently shaded regolith at the lunar south pole. It assumes that the moon will be visited first, Mars second. A permanent station called “Shackleton” near the lunar south pole refuels LBVs and is the base of operation for exploration of the lunar surface via a slowly developing system of dirt “highways” and automated trucks that run along them, carrying water and supplies to the lunar equator.
6. A reusable Mars Shuttle, a single-stage conical vehicle 15 meters long, with a basal diameter of 6 meters. The Mars Shuttle is about 70% larger than the Earth Return Vehicle in Robert Zubrin’s Mars Direct Plan. Its dry mass is 7.5 tonnes, excluding a 4-tonne crew module (which fits in its cargo hold) and a 5.5-tonne aeroshield. The crew module has 28 square meters of floor space; about a quarter the size of Mars Direct’s Hab and half the size of its ERV. A Mars Shuttle needs 130 tonnes of liquid oxygen and methane fuel on the Martian surface to push itself and 20 tonnes of extra liquid oxygen and methane into a high Mars orbit; the 20 tonnes is sufficient to push the Ihab and the Shuttle out of high orbit and onto a fast trajectory back to Earth. To make 150 tonnes of oxygen and methane, 7.5 tonnes of liquid hydrogen must be landed on Mars. Subsequently refueled using Martian water, the Mars Shuttle can lift twenty tonnes to high Mars orbit or to Phobos and can fly to either moon and return to Mars.

The plan derives its ideas from various authors, but especially from Michael Duke’s “A Lunar Reference Strategy” (which can be seen at http://members.aol.com/dsportree/MM22.htm) and from a recent proposal from NASA’s NExT Team proposing a station at L1 called Gateway (see http://www.space.com/news/beyond_iss_020926-1.html).

Filed under: Fiction on September 25th, 2003