Five Roadblocks to Mars

 There are lots of technological challenges that must be solved before going to Mars. Even if a rocket has the delta v and capability to make it to Mars, right now such a trip would be a suicide mission. My list of the major (showstopper) technological challenges are:

• Refueling
• Food
• Radiation protection
• Artificial gravity
• Robotic construction of Mars base

 When we have solutions for these five challenges we can reasonably think about going there, but if we want to create a settlement and stay there, we must first know whether only 38% of Earth gravity is enough to develop healthy babies. No healthy babies - no Mars settlement. Testing artificial gravity systems on the Moon would be a good way to try to answer this question.

Refueling

Propellant is the name of the game. With the current technology of rocket engines, we need lots of it, at convenient places. Fortunately, the Moon has copious amounts of propellant components laying around the surface – water and oxygen. Propellant depots in LEO and the E/M Lagrange points will be the catalyst for space exploration and a thriving space economy. I’m not that concerned about the technical complexity of refueling a spacecraft, I think the harder part is the logistics, timing, and economic incentives of building the propellant infrastructure.

Food

Everything eats – even galaxies. Humans will only go so far as their food will take them. Growing food in microgravity and on other planets will have to be worked out in advance, to a very high degree of reliability and in bulk. The Moon is the perfect place to practice space farming and learn from mistakes with the safety net of re-supply from Earth.

Radiation Protection

The initial trips to Mars are going to be months and months and months long – absent some unexpected breakthrough in propulsion. This is when humans will be most vulnerable to damage from galactic cosmic rays. I think that protection once on the Moon or Mars will be adequate (3m of regolith or a nice lava tube), but it's the long trips outside that are dangerous.  Perhaps the protection strategy will be multi-faceted; water stored in the spacecraft walls, drugs that enhance the body’s natural resistance, better cancer treatments. I prefer to dream big on this one and advocate the mobile mini magnetosphere (admittedly a technological stretch).

Artificial Gravity

Every new study that comes out confirms that microgravity plays havoc with animals who evolved in significant gravity.

Serious havoc such as:

• Bone loss
• Muscle atrophy
• Vision degradation
• Cardiovascular deconditioning
• Immune system malfunction due to gene expression changes
• Blood anemia

Artificial gravity systems are going to be needed on long-crewed missions.  

 

Robotic Construction of Mars Base

The consensus strategy for a Mars base is to build as much as possible before the humans arrive. I have no problem with that concept. The question is how much can the robots do? They can do more on the Moon because of human assistance with near real time proximity - but not on Mars. The Martian bots will have to be smarter than the semi-autonomous versions on the Moon. Hardware assembly routines will have to be practiced on the Moon and then coded for the bots to perform on their own on Mars. Construction will take longer and, inevitably, stuff will go wrong (Murphy’s Universal Law).