-[  ]-

The faint wind picked up the ice and snow from the maw of the giant machine, its black bulk lumbering slowly across the polar wastes, its tracks crunching on the pitted ice.

Polar 2 was one of a new class of vehicles, its purpose was to be part of a chain of events in one of the most ambitious schemes humanity ever considered.

The vehicle was great dark block, its surface scarred with cables and vents, its huge bulk taken by the twin tracks on either side. Despite its massive size, (some 10m wide, by 25m long, and 8 high), the low Martian gravity did a lot to reduce its downward force, and despite the wind carved and ablated ice it did not sink more than a few centimeters. At the front of the vehicle a greater turning claw, a series of hardened titanium nitride coated points arced down towards the ice and ripped up the material into its maw. Like a comet the faint wind gave the vehicle a sparkling white tail, the great cloud covering its front end almost covering the hidden dark mass.

Polar 2 was an extraordinary vehicle, the technology that had been used for the continued survival of the early colonies had been meshed together to form this vehicle, its sister vehicle Polar 1 also borne of the mongrel mixture of parts. From above the giant ponderous vehicle had two tails, one the fantastic changing white on, white curls almost lost on the near featureless bleak ice, the other far more sinister, a uniform black line, a physical indication of the path of the vehicle.

The thinkers behind the terraforming project had to think in practical terms about what they could do with their limited resources.

The black line was made from extremely fine black dust, most had become lodged in the fissured surface of the ice, some had blown from the surface leaving a gray shadow in the ice to one side.

Mars’ polar caps were a positive bounty of resources; they would be an essential and inevitable part of any terraforming effort. The caps were mostly ice and dry ice, both extremely useful raw materials, the ice would take care of itself in time, forming a hydrosphere when the planet warmed up, but it would do nothing until there was a sizable atmosphere, which could retain the heat of the sun, and allow pressure for liquid water. Simply loading the caps into machines which would release CO2 to create an atmosphere would be impossible, it would require huge amounts of equipment, and there would be nothing to stop there new atmosphere from precipitating back out once it had to be made, and so longer term solution had to be found.

Polar 2 was almost a solid block of machinery, space was at a premium inside its protective outer shell, banks and banks of chemical processors nestled around the central reactor, its warmth and electrical power sustaining the vehicle.

A long term solution was found, it would require much less resources, and the method would be far more practical, although what the atmosphere needed initially was CO2 to warm up the planet, and lots of it, Polar 2 was to not heat up and release this gas, its plan was more elegant.

The polar ice would be separated into to its two main parts, the dry ice and the water ice. The cooling vents from a nuclear reactor would heat the raw material, the initial temperature would not be high, but a good 60 degrees warmer than outside, the water ice would still be solid, but the dry ice would sublime off as a gas. The rapid increase in pressure in the primary heating chamber would drive the mixture of finely cut water ice and CO2 through the machine, the water ice would be separated off, and leave the vehicle as a white plume driven by the wind of CO2. Some of the gas however would be directed into the banks of chemical processors in the heart of the machine. In these machines the CO2 would be converted into oxygen gas (which would be liberated into the atmosphere), and a fine carbon powder.

This fine powder was the purpose of Polar 2, this material spread over the polar landscape would decrease its albedo, the darkened surface absorbing more of the incoming light. The conversion of the Polar caps would be done by the sun rather than by human effort, these dark surfaces would warm far more quickly than before, eventually pushing the local temperature above the sublimation point of CO2, at this point the gas would be readily released from the caps, greatly thickening the atmosphere. This thickening would then increase the atmosphere’s ability to hold heat, and so the temperature would continue to rise, eventually to the point where even the water ice would melt.

For now the vehicle continued its solemn march across the frozen wastes, it had no mind to conceive the changes that it would bring, nor could it be able to comprehend the implications it would have for its designers. For now there was only the muted roar of the destruction of the ice, and screams of the exiting gases, carried on the thin wind.