We are bringing a huge repository of human knowledge with us to the new world. The problem is, a lot of that knowledge is only applicable to Earth environment. We have a library of metallurgy texts but those only deal with metal processing in a particular atmosphere; we know how to build a coal power plant, but there is no coal where we are going - and even nuclear power plants require a huge amount of water daily just to cool themselves (and generate electricity in the process, in their huge steam turbines). We have a working knowledge of Earth agriculture, Earth meteorology, Earth geology; and to make matters worse, there’s just a few hundreds of us, maximum - for a whole self-sufficient colony.

Our vehicle and building plans have been designed with all this in mind - as automated as possible, as simple to build as possible, as reliable as possible. However, to get there, certain compromises had to be made. The buildings aren’t designed with comfort in mind, nor are they optimal for the job at hand. We have but the core to improve upon, but the core is there to make our early days on the new world survivable.

Vehicles

Vehicles are essential to anything we do in the colony. With our workforce limited, and logistics tricky at best, the designs are fully automatic, but not autonomous, receiving their orders from a command centre. This way, only a few people have to oversee their day-to-day duties and logistics are limited to repairing damaged vehicles and replacing their power sources as they fail.

Our starting set of vehicle plans is as follows:

• A bulldozer, to prepare land for construction, as well as making land easier to traverse for all the vehicles, especially our trucks.
• A digger, to excavate large underground areas for safer habitation and to make way through mountain ranges. Apart from the digging itself, it automatically erects support structures as needed.
• An explorer, mapping the surface of the planet and prospecting for resources.
• A miner, to prepare mineral resources for extraction. In fact, this is not a single vehicle, rather, it is a more or less self contained mine; in practice, they can be used to either prepare the ground for a dedicated mine staffed with humans or it can extract resources on its own, especially useful when the mine in question is far from a colony and a full fledged mining colony isn’t necessary or desirable.
• A cargo truck, moving resources from place to place such as moving ores from a mine to a smelter. They are not necessary where resource piping is in place (so there is no need to have a truck transport metals to a factory - a resource pipe is faster and cheaper). They are indispensable for long range transportation, though - at least until we decide to work on a railway system.
• A construction vehicle, to construct buildings. The construction vehicle takes prefabricated building kits from your factories and uses them to construct buildings in field. The construction usually takes no more than a few days, although there are buildings which are trickier to construct (fission/fusion power plants, for example). This is also one of the few vehicles which are manned - their automation is limited to driving. This however still makes them useful for colonist transportation if there are no dedicated personnel transports available (and it makes them perfect for starting new colonies - you send a few ConVecs loaded with the basic buildings, and when they’re done building, you unload their crew in the new colony, and send any ConVecs not needed there back to their home colony).

Power plants

Power plants are critical to the survival of any colony. The first power plant in each colony is the Command Centre. While it’s power supply is effectively infinite (well over half a century), it’s power output is very low. We also brought a seed power plant with us, but that is only a temporary building. For a self-sufficient colony more power generation is needed. Our options at arrival are as follows:

• Solar Receivers - These receive microwave power sent by orbital solar satellites. They produce a sizeable amount of power, require little maintenance, are easy to construct and produce very little waste heat. The major issue is you need to have said solar satellites in orbit - while we can take some Earth-built satellites with us, they are a finite resource until we can re-achieve space flight. As such, they will either have to take up a lot of valuable space on the seed ship, or only see limited use until we can launch more. They can also be deactivated, which makes them perfect as backup power plants for all the colonies.
• Solar Power Plants - Directly utilizing the insolation on ground level, these power plants are much less efficient than solar receivers. They produce a very small amount of power (heavily dependent on insolation), require little maintenance, are easy to construct and produce very little waste heat. Unlike solar receivers, they do not require a solar satellite in orbit. They do require large amounts of refined materials to build, but that shouldn’t be an issue in any decent colony.
• Nuclear Fusion Plants - Productive fusion power generation is a relatively recent technology. Apart from powering our spaceship, we can also bring some prefabricated reactors with us for use in the colony. They produce a huge amount of power, require a lot of maintenance, produce a huge amount of waste heat (and sadly, even when running at low power) and require a small amount of fuel. At the moment, the only mechanism we have available is Deuterium-Tritium fusion, which requires a supply of deuterium (plentiful where light hydrogen is) and lithium (rare). This particular reactor has very high maintenance requirements, produces a huge amount of waste heat and is pretty much as bad as fusion reactors come. We hope to reach more “advanced” fusion reactions, such as Deuterium-Deuterium fusion, which removes the lithium requirement and lowers the maintenance requirements, while unfortunately also severely impacting the power density (this is the primary reason why we don’t have those from Earth - at the time of the cataclysm, they simply weren’t competitive). Fusion power plants are very technologically advanced and require a lot of advanced materials and processes in their construction, which means we can’t build them until we prepare the required industrial base and redesign the technology to fit our capabilities and resources. Also, while hydrogen and its heavy isotopes are very plentiful in the universe at large, rocky planets near their respective suns might be lacking, because hydrogen is a very light gas and is easily swept away by the solar wind.
• Nuclear Fission Plants - A mature technology at this point, various fission power plants have become plentiful on Earth. Effectively infinite fuel supplies along with low dependence on fuel costs, a very high safety factor, effectively nil waste and various practicality benefits (such as swift capacity changes to meet changing demand) made fission power plants the principal large-scale power source of the 21st century and beyond. They produce a large amount of power, require a moderate amount of maintenance, produce a large amount of waste heat (easily scalable with power demand) and require a small amount of fuel. Full scale plants are quite difficult to construct, but much less so than fusion power plants and we expect to be able to construct them as soon as we arrive, with just a tiny industrial base required. The fuel should be relatively plentiful, but might be tricky to find in exploitable quantities.
• Radio-isotope Thermoelectric Generators - Apart from full scale plants we also use small fission power plants in our vehicles - unlike their larger brethren, these use radioactive isotopes with very short half-lives, on the order of years or decades (shorter half-lives meaning higher power densities, with correspondingly lower lifetimes). The vehicles we’re bringing from Earth are equipped with Po-210 radioisotope thermoelectric power plants and have effective lifetimes around a hundred days; however, each vehicle only needs a few kilograms of fuel, which is of critical importance (a kilogram of Po-210 produces around 140 kW of power), and the decay produces alpha particles almost exclusively, which makes it very safe to work with even in personal vehicles. The required polonium isotope is produced on the spaceship at the time of its arrival to the target system.
• Chemical Plants - These power plants operate by oxidizing or reducing various fuels and using the resultant heat to power steam turbines. They produce a tiny amount of power (especially on a per-mass basis - the difference between a fission plant and a chemical plant is around six orders of magnitude), require little amount of maintenance, produce a huge amount of waste heat and require huge amounts of fuel. They will probably be of limited use for main power generation. They might be useful as a production facility instead - employed in waste processing, or producing carbon dioxide and water for our farms for example.

Apart from large industrial power plants, there’s also vehicle sized power plants for various applications. The most promising engine is an electrical engine, thanks to it’s great versatility and easy maintenance. It will work without an oxidative agent supply, needs relatively little cooling (simple radiators are quite enough) and performs well at various levels of load. Any of the power plants specified earlier could probably be adapted to work with the basic electrical engine. Another useful power source is a pre-charged fuel cell - cheap, easily replaced, relatively long lasting fuel supply. Of course, they have to be charged first. If we find ourselves on a relatively hospitable planet, we may even explore simpler engines (such as pure chemical engine), but in the end, we don’t think it will be necessary, unless we’re in short supply of some key materials.

Heat management

Heat management is a crucial part of any space-based colony or vehicle. The universe rules are simple on this matter - it’s impossible to get rid of heat; you can only transfer it elsewhere, which usually means you need something cooler to transfer the heat to, as otherwise you receive more heat than you lose. And outside of a cool, thick atmosphere, there’s few ways to get rid of heat. We will have a look on the three basic types of heat transfer:

Conduction

Thermal conduction is a process in which two objects in direct contact exchange heat. This is the kind of heat transfer that happens for example when you touch a hot bar of iron, or in the bar itself if heated non-uniformly. Conduction is usually very fast and the rate of conduction depends on the material (metals are usually great thermal conductors, while ceramics and aerogels can have ridiculously low thermal conductivity) and the temperature difference.

This heat transfer method will probably only be used to transfer heat to another heat dispenser.

Convection

Thermal convection is a very important heat transfer method, especially in materials with relatively little thermal conductivity, such as air. The basic operating principle is that the working fluid comes into contact with the target object, heats up (or cools down, depending on the temperature difference) and moves out of the way. This way, a lot more of the working fluid comes into contact with the target object and the thermal conductivity of the fluid is less of a concern (although water will always mean more heat transfer than air). This is the driving force behind most of Earth’s atmospheric and oceanic currents - hot fluid rises, forcing colder fluid lower.

Convection is a fast way to remove excess heat, but it requires a large body of working fluid. As such, it will be the most effective in closed systems and on a planet with usable liquid coolant or an atmosphere.

Radiation

Thermal radiation is produced by every bit of matter. The speed of radiative cooling depends on the temperature of the material and it’s emissivity. Every material also absorbs radiation from it’s surroundings - so if an object radiates 300 W, but receives 150 W from it’s environment, it will only release a net 150 W), and this effect is proportional to the emissivity - as such, the best radiators are also the best radiation-absorbers. This is also the principal method by which planets (and other space objects) lose heat, since the emitted heat isn’t retained by the gravity of the object (conduction will only carry the working fluid so high). The upper limit of radiative emission is given by Plank’s law, describing the most efficient emitter - a perfect black body.

Radiative cooling is very effective for high temperature processes and much harder for human temperatures. As such, our radiative systems will be separated into life support (0 - 100 °C) and industrial (more than 100 °C).

Evaporative cooling

Evaporative cooling is very fast, but it consumes vast amounts of working fluid. The basic principle is that liquids (or solids) undergoing phase transitions to gases will have to absorb large amounts of heat from their environment. Since the rate of evaporation depends on pressure, using evaporative cooling in vacuum will result in flash freezing due to the ease with which the material evaporates.

If we find suitable cooling material in solid or liquid form, this might be workable on a large scale as well (for example, in power plants). Otherwise, it will probably only be used in laboratory conditions or as part of a closed-cycle system.

Summary

Heat management is trivial on cold planets, especially with liquid water available in quantity. However, a hot planet will be a hell-hole requiring vast heat management areas; in fact, planets too hot for liquid water will probably be unlivable altogether, unless the night temperatures are low enough to enable cooling through the night. In such a case, most heat producers like factories and smelters should only be used during the nights, all radiators will be covered with reflective covers during the day and as much of the colony will be underground, well isolated from surface conditions. It may be possible to reduce the surface temperatures with time (increasing cloud albedo and reducing the greenhouse effect), but that will require huge amounts of resources and time. All in all, hot planets are a true test of a commander.