Planning the initial trips to be one way makes a fair amount of sense, but what little I’ve gleaned about Mars One doesn’t really seem entirely based on the premise.
The media spectacle concept: Stepping up to go to Mars for the rest of your natural life seems an objective diametrically opposed to becoming a reality TV star. 2+ years cooped up with 4 people and your only outside contact is people who need you to “perform” for a TV audience to keep the funding rolling in.
Over-enthusiastic mission-to-mars proponents like to draw an analogy between, say, Columbus and potential Martian settlers. This seems to be an extreme exercise in “unhistory”. Unlike Mars, the New World was the same distance from the sun, with the same life-essentials such as gravity, gasses, solar radiation levels, tolerable temperatures, pressure, soil, exposed liquid surface water, familiar building materials, compatible food sources, etc. Most importantly, it was the indigenous peoples that helped keep settlement from having a much higher cost.
Settling virgin lands, on Earth, comes with a heavy cost. Sending people to Mars to live out their lives is one thing, sending them to die is another. I think a 50% rate of attrition over the first 6 years should be expected and treated as baseline. Thus, for example, the first human launch should consist of three spacecraft carrying 5 people each, with the assumption one entire craft will be lost and 2 or 3 members of each the remaining craft will not reach the surface or Mars alive.
As much as I’d love to see man land on Mars in my life time, I think we need to take a better look at the ground before we do that. I don’t mean orbiters taking pictures or rovers scratching rocks. What we need is to get down under the surface, find out how far down before you start finding suitable building materials. There are no trees or plants, so the only native building material is rock, and the stuff at the very surface is dust and fragments. You’re not going to build an air-tight house with that.
Once we have the ability to use local building materials in construction, then we need to build at least two habitation sites. It’s gonna be really bad if you build one and something happens to it while the settlers are en-route, and survival rates go up if you increase the number of potential supported landing sites. It’s going to be a great shame if, upon arrival, the landing site is obscured by a dust storm and the first settlers die in orbit waiting for clearance to land. Additional landing sites = additional opportunity for success.
The real issue doesn’t arise until your first group of settlers are on Mars. Getting people there isn’t the real difficulty, keeping them alive is: the first follow-up vehicles are absolutely crucial, but you have to assume some rate of attrition in vehicles making it to Mars. If luck is against you, it could easily be that all the attrition happens upfront and your first X follow-ups consistently fail to make it.
This is going to be especially hard on a single-site Mars settlement. Occupants of the space station have a rescue vehicle so they can escape to Earth if the station becomes uninhabitable. Roanoake settlers may have had Hatteras Island as a backup, they certainly had the mainland as an option.
My sights would be set on the following preliminary goals.
- Acquisition of on-Mars resources: the ability to access construction materials, energy, etc;
- On-Mars assembly or Martian resources: A simple fabricator and assembly machine pair;
- Analyses of building options: over-ground shelters? cave-based habitation?
- Build and pressurize some proof-of-concept Martian living spaces, pressurize with Martian gasses.
- Acquisition of off-Earth resources, e.g. near-Mars asteroid mining, at some point you’re going to need resources in-orbit around Mars for things like lander repair, etc,
- Accumulation of support resources in orbit (for a start: at least one spare lander),
- Accumulate starter supplies near/at constructed habitats.
What do I mean by starter supplies? Oxygen, water, soil, seeds.
Having something like a fabricator+assembly pair build a crude rover of some kind using all-Martian resources would be a major milestone.