Mars One plans to send four astronauts to Mars by 2025. The company has been notoriously vague on the details of establishing a colony there, though, for good reason: Setting up a base on another world is just plain difficult. Here's how it could work.
Step 1: Launch ComSats
Start by placing a pair of communications satellites, one in a Mars stationary orbit and the other in orbit around the Sun, so that future colonists can stay in touch with Earth throughout the year.
Technical feasibility: High. We know how to build and launch satellites, and we've been communicating with spacecraft near Mars since 1965.
Step 2: Deliver A Rover
Use an intelligent ground vehicle to scout the best location for long-term settlement–flat terrain, with ample sun and water–and act as a beacon to guide future shipments.
**Technical feasibility: **Moderate. Curiosity advanced our collective ability to land large craft, but rovers are not yet efficient scouts. For instance, in just more than a year, Curiosity has traveled about five miles.
Step 3: Set Up Habitats
Land a series of cargo missions containing inflatable habitation pods and a second rover. That rover will tow the pods to the settlement location and roll out thin-film solar panels to fuel the production of water and oxygen from Martian soil.
**Technical feasibility: **Low. Landing loads in close proximity is hard. A rover would need enough power to tow cargo, and such a design has not been tested.