Another big question that we have to prepare for during space colonization is that a species might change very quickly once on the new planet. Ecologists are realizing this now because recent research shows that evolution can happen quickly ... An example of the rapid evolution of species we can see occurs on the Galapagos Islands, where the birds change and interbreed, and species disappear and appear.

So even if we bring one species that we've figured out does something, it might change completely within a couple of generations. Ecologists don't even know how many species there are on earth, much less the general rules of how species interact and respond to each other, nor how this changes over time. Ecosystem studies are useful because ecology is just starting to ask these questions. And while we're waiting for space colonization, this ecological knowledge might help us survive on the earth!

3D printing and the rocket engine are the two inventions that will eventually enable space settlement. With 3D printing, you can cut that supply chain and make all the spare parts you need locally ... A colony cannot survive if it is dependent upon a supply chain from Earth. We must mine asteroids for their raw materials (making solar arrays, colony structural materials, etc from the raw materials in Near Earth Asteroids). Mine comets for water. Water is for drinking, bathing, radiation shielding ctrolyzing into hydrogen and oxygen for rocket propellant and for use in fuel cells.

As far as technologies needed for a pathway that leads to Mars, We assessed 10 high priority areas in terms of the technical challenges. The 10 high priority areas are: Mars Entry, Descent and Landing (EDL), Radiation Safety, In-Space Propulsion and Power, Heavy Lift Launch Vehicles, Planetary Ascent Propulsion, Environmental Control and Life Support System (ECLSS), Habitats, Extravehicular Activity (EVA) Suits, Crew Health, and In-Situ Resource Utilization (ISRU - using the Mars atmosphere as a raw material).