It seems to me….
“My view is that we should go back to the Moon, build up the infrastructure to make flights there commonplace – be comfortable with it – then use that infrastructure to expand and go to Mars.” ~ Jim Lovell.
From a scientific perspective, human life on Mars could probably tell us more about the solar system’s past, as well as the history of our own planet, than we could ever learn from living on just one world. It would also be a phenomenal steppingstone in the conquest of exploring other worlds. Theoretically, we could use a human settlement on Mars as a template for future colonization missions, perhaps even to extrasolar systems. Mars could then, in the not too distant future, serve as a vital pit stop for interplanetary missions.
Scientists and engineers seem fairly certain that a human colony on the Red Planet is not only likely in the future, but inevitable.
Mars is our closest celestial body with the greatest potential for colonization but Mars would not be an easy place to live. From a biological standpoint, establishing a settlement on Mars would be of comparable difficulty to establishing one on the Moon. At a mass only a little more than 10 percent of Earth’s, and gravity only a bit more than ⅓ of our own, Mars is comparatively tiny, dry, and extremely cold, with the barest hint of an atmosphere composed almost entirely of CO2. Mars does have some water, in the form of ice, and possibly even some liquid saltwater.
Establishing even a small permanent outpost on Mars would require sending hundreds to thousands of tons of material to its surface. This would necessitate multiple launches, probably of the order from dozens to hundreds. Sending hundreds of tons of payload per rocket to other worlds from Earth requires an extremely high delta-v. As more weight is added to the spacecraft, fuel requirements increase exponentially. A lower delta-v could be achieved by launching a corresponding payload from the Moon which would require comparatively less fuel than from Earth.
Going into space results in a host of stress-like responses. Many of these extend down into our genome as well as our immune system and gut microbiome. Human bodies are not well suited for micro-gravity; it results in changes to our circulatory system, makes us distended, and causes vision changes. Physical problems of long-term space flight include the stresses of microgravity, cosmic radiation, and “headward fluid shift” where blood and tissue fluid collect in the head. Body changes are in the eyes, carotid artery, DNA expression, and cognitive performance. The longer the duration spent in space, the more symptomatic upon return to Earth.
Radiation is a particular concern during any long-term Earth-orbiting presence or for getting to places like Mars or asteroid targets. Our cells, especially our neurons, are not tolerant of the increased radiation environment in space. During stays of extended duration, hazards from solar and cosmic particle radiation increases significantly from the environment of low Earth orbit where Earth’s magnetic field offers substantial protection.
Traveling to Mars, an astronaut might be exposed to an average radiation dosage some 700 times that on Earth; during a fairly typical 6-month journey to Mars an astronaut might receive the equivalent of about 60 percent of a normal lifetime radiation exposure on Earth.
Finding the right shielding that can protect people is challenging as any space mission is limited by mass; more mass requires more fuel for propulsion. The problem is further complicated by the fact that improper radiation shielding could possibly make things worse. When very high energy cosmic particles impact a material, it could initiate a burst of slower but harmful radiation in the form of particles such as neutrons. While protected from the original cosmic radiation, attempting to block it would result in the energy being absorbed by the body rather than simply passing through.
A possible improvement is to include a layer of shielding material with a high hydrogen content, possibly a lithium compound such as lithium hydride, with a similar mass to the atomic nucleus to the damaging neutrons capable of absorbing energy in elastic nuclear collisions thus reducing secondary particle energy.
Any initial actual economic value of a Mars colony to Earth would be in the intellectual property that results from the vast amount of innovation that would result from humanity’s quest to conquer the new frontier itself. Challenge and necessity brought on by human expansion on Earth have spurred invention for hundreds of thousands of years, and that will continue as we move on into space.
In the far future, it might be desirable to terraform Mars so as to more easily function on the planet’s surface and to more readily serve as a second home for humanity. Terraforming is a process by which a planet’s biosphere is altered with technology in order to make it more suitable to human and Earth-based life. Terraforming an entire world would necessitate many factors about the planet’s atmosphere and surface be changed to accommodate such life. There are four main factors that would need to be addressed for this process to occur: atmospheric pressure, atmospheric content, temperature, and liquid water content.
Numerous treaties preclude government ownership of celestial bodies. Any other place we may one day choose, or need, to exploit is supposedly considered the property of ALL Earth governments and to be used for the betterment of all peoples. But this model is utopian at best, unrealistic in any regard, and therefore cannot hold in the long term.
If terraforming Mars is successful, Mars would be its own self-sustaining world completely independent of resources from Earth. No natural nor manmade phenomenon would then have the capability to stop the advancement of humanity outwards and towards the stars. At last, we would be an interplanetary species.
The universe is vast and demands our exploration. After an initial stop on the Moon, Mars would be the next in the potentially thousands of steps necessary in our endeavor to become an extraterrestrial species. One day, humanity will leap towards the stars in an attempt to learn and discover more about the universe and more about ourselves in the process. The universe is our neighborhood and it is time to open the front door and explore it.
That’s what I think, what about you?
 James Arthur Lovell Jr. is a former NASA astronaut, Naval Aviator, mechanical engineer, and retired Navy captain. He orbited the Moon on both Apollo 8 and 13.
 Scharf, Caleb. Deep-Space Shielding, Scientific American, https://blogs.scientificamerican.com/life-unbounded/deep-space-shielding/, 5 June 2019.