Aresian Well
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The Aresian Well (not to be confused with artesian well) is a macroengineering project comprising a pipeline from the North Polar Cap of Mars to a point at or near to its equator, and a Martian beanstalk (or orbital tether) which can deliver water (or other volatiles) to a point on the beanstalk above areosynchronous orbit. From there, the water (suitably packaged) can be delivered to anywhere in the inner solar system at negligible cost compared to the cost of lifting water from Earth.
The term beanstalk is used here, rather than space elevator, as flow is continuous rather than via an elevator-like hoisting mechanism. It is the term that inventor Mayer uses in his descriptions.
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[edit] History
The Aresian well concept was invented by Alastair J.W. Mayer circa 1987, and first published as a poster paper at the Case for Mars IV conference in Boulder, Colorado in 1990. A subsequent paper was presented at the 10th Princeton/SSI/AIAA Conference on Space Manufacturing, 1991 under the title "The Aresian Well: Piping Martian Volatiles to the Inner Solar System."
Subsequent robotic exploration of Earth's Moon and of Mars may indicate the presence of water in limited quanties at the Lunar South Pole, and in subsurface deposits in more equatorial regions of Mars, but the permanent ice caps of Mars still represent the largest known water deposits beyond Earth and this side of Jupiter's moons (Europa, for example).
[edit] Concept
The system includes a number of components:
- an ice mining facility, the "Wellhead", at the polar cap, either a strip mine or a well-like system where ice is melted using heat from a nuclear reactor, sited on the edge of the cap at about 115°W, 80°N
- a pipeline running roughly straight south along 115°W to Pavonis Mons, through the Vastitas Borealis to about 47°N where it skirts the edge of the rugged terrain at Alba Patera, then again continues south along 115°W to the base of Pavonis Mons at 7°N, and thence to "Beanstalk Base". Depending on the anchor site for the beanstalk (see below) this may be the Pavonis Mons summit at 113°W 0°N. Total distance is about 4900km.
- the anchor site for the tether or beanstalk depends on a solution to the Phobos problem. Mars's moon Phobos orbits below areosynchronous altitude, and thus there is a collision risk. Possible solutions include moving Phobos, oscillating the tether, or hanging the tether at an angle (a catenary) anchored at 5°N, which will move the beanstalk out of the path of Phobos.
- the beanstalk, a cable system whose center of mass is in areostationary orbit with the lower end anchored on Mars's surface (see the space elevator article for general discussion of this concept). It is calculated that such a cable could be made of carbon fiber (not carbon nanotubes, which are much stronger but an unproven technology) with a modest 1.4 taper factor (the cable would need to be 1.4 times thicker at orbital altitude than at ground level).
- a counterweight at the top end of the beanstalk, above synchronous orbit. Its rotational speed would be higher than orbital velocity for its altitude, so anything released from this point would "fall" away from Mars. A facility for packaging the water (or other volatiles) and releasing it on an appropriate trajectory to the customer would be located here.
[edit] Fiction
Mars-based beanstalks have appeared in science fiction, including Arthur C Clarke's 1979 The Fountains of Paradise, as background (the story primarily concerns the construction of an Earth-based space elevator), Kim Stanley Robinson's 1992 Red Mars (part of his Mars trilogy) and in Larry Niven's 1999 Rainbow Mars, in a fantastical parallel history as an actual living beanstalk.
The pipeline and combination "Aresian Well" concept has not appeared in fiction, although Alastair Mayer is said to have a novel in progress centered on the construction of same.
[edit] References
- SPACE MANUFACTURING 8 ENERGY AND MATERIALS FROM SPACE (Proceedings of the Ten Princeton/AIAA/SSI conference on Space Manufacturing), Princeton, May 1991.
