In part one and two of this series we looked at what space missions current human technology could undertake right now, and then focused on what options Earth’s moon might provide. So far, we have established that there are still technical challenges to overcome, but the prospect of lunar colonization has been within reach since the days of the Apollo missions. In this part of the article, we will focus on Martian colonization options and the challenges they present.
Visiting and eventually staying on Mars has been a goal of manned spaceflight since the dawn of the space age. Werner von Braun believed a human exploration of Mars was essential to the American space program. Other plans to explore or colonize Mars still use many of the basic concepts from his proposed mission.
Missions to Mars do not always end as mission planners might like, lost spacecraft, landers, and rovers are more common than operational machines. Missions from the European space agency, India, Japan, China, and Russia, have joined earlier missions by the Soviet and NASA space programs, with varying degrees of success. The emerging private space sector also has plans for Mars missions, with SpaceX planning a permanent Mars base sometime in the 2020’s.
The first challenge Mars presents is the distance of the aptly named red planet from Earth. The Moon is much closer and we have sent people there and back already. Mars does not share that history. We have sent probes and robots to Mars, even proposed a sample return mission, but we have never sent real live human beings there.
The distance is a challenge for several reasons, among them: exposure time, communications lag and self-reliance. While all of these challenges are obvious, the impact of the inability to have real-time communication may not be. The mission will be increasingly out of sync with mission controllers on Earth, and subsequently slower to respond to changes in mission objectives due to unforeseen circumstances.
Space travelers will also be entirely reliant on one another and whatever supplies they take with them. While eventual resupply might be possible over the course of a long-term mission, immediate response to losses in transit or on the surface of Mars will be impossible. The colonists will have to improvise with what they have on hand.
Most proposed human spaceflight missions to Mars expect a travel time of about nine months to and from the red planet. This flight time introduces the next challenge to colonizing Mars, in the form of radiation exposure. Energetic particles and ionizing radiation continually bombard Mars and the space between there and the Earth just like the Moon. Technologies to minimize exposure during transit and while on the surface of Mars must be developed beyond our current ability for colonization.
Mars is only about a third the size of Earth and has about a third of the gravity we are used to. The long-term effects of low gravity and weightlessness are another challenge to colonization. A number of medical conditions could develop for colonists, and there are currently no means to combat these conditions.
Medical care in transit or on Mars is also a challenge. Humans are prone to illness and injury, and our bodies have evolved healing strategies that work well with Earth’s gravity, air pressure, and atmospheric makeup. Effectively treating inevitable disease or damage will require us to develop ways to recreate those conditions, especially if surgery is necessary.
Building the colony structures on Mars presents similar challenges to building on the Moon. Underground structures versus above ground structures, radiation shielding, energy production, life support and all the requirements for a sustainable human presence are the same. Only the greater distance or Mars from Earth multiplies the cost, the time required and the possibility of loss.
In the final part of this article, we will compare and contrast a Lunar versus Martian colony. Which one is most advantageous for a continued human presence in space and for the continuation of our species? Those answers and a modest proposal from the author will sum up “Feasible Missions – Part Four”.