The Long and Winding Road to Mars

As the race for launching a manned mission to Mars progresses, more and more questions arise about the challenges and dangers participants will face along the journey – from the journey itself, to the landing, and, of course, actually living and surviving on the red planet.

The journey to Mars will be long. According to NASA, a manned journey will take about 240 days using current technology, providing that the time slot during which Earth and Mars are at minimal distance between one another, occurring once every 26 months, is taken advantage of. Innovative technologies may shorten the journey by some 100 days, but even so, these are still long months in space.

Astronauts undergo strenuous training before going into space. As early as the launch, the g-force, or gravitational acceleration exerted upon the astronauts rises to 3g, i.e., three times the gravitational force at sea level. The higher the g-force, the harder the heart needs to work in order to pump blood through the body; at 4g, most people lose consciousness due to a drop in the blood pressure.

One major concern involved in the long journey is radiation. As opposed to Earth, space provides no protective atmosphere to block the radiation. Engineers are exploring various solutions to the dangers of exposure to radiation during the long journey to Mars, and NASA has even suggested that astronauts freeze sperm or egg cells for fear their fertility would be damaged by the radiation. 

A recent paper published in Proceedings of the National Academy of Sciences alleviates some of this fear. The researchers kept a sample of frozen mouse sperm on the International Space Station for nine months, and then used it to fertilize eggs. No differences were found between the pups born of the sperm sample sent to space and the control sample that stayed on Earth. Although the sperm’s DNA was slightly damaged due to the stay in space, the egg corrected these errors during fertilization. Researchers are also testing the effect of radiation on plant seeds in order to find resilient plants that will survive the long journey, which will enable developing agriculture in the distant world.

Nevertheless, it is important to bear in mind that the International Space Station is only 300-450 km from Earth, close enough to benefit from the protection of the Van Allen radiation belts. The belts are comprised of charged particles orbiting the Earth, kept in place by its magnetic field. Only one percent of the particles is not skewed by the magnetic field and reaches the atmosphere. A journey to Mars would involve crossing the Van Allen belts and traveling beyond them and the spacecraft making the journey will pass an area with much higher radiation levels than those at the International Space Station.

Rocks on Mars. Photograph by the rover Curiosity. Credit: NASA/JPL-Caltech/MSSS

Reaching Mars

After the long months in space, as they approach Mars, the astronauts will be facing a new challenge – landing the spacecraft. To date, space probes that landed on Mars used parachutes to slow down before landing and airbags for protection. For larger probes, researchers have developed a type of a flying crane that enables gradual lowering of the research probe onto the surface. But a manned spacecraft will weigh about 20 tons, and no technologies that can negotiate such a weight to the surface of Mars have so far been developed.

The landing site will be selected ahead of time; in fact, NASA is already exploring locations that will allow the crew members to set up “camp” and explore the area. In a NASA-hosted workshop two years ago, researchers discussed 47 suggestions for different landing sites, with the aim of locating sites that provide an appropriate landing environment and reasonable living conditions.  

And after the landing? Mars’ average temperatures are around -60 Degrees Celsius (during summer, the daytime temperatures can reach 20ºC at the equator, with a deep plunge below zero during nighttime). And the planet’s atmospheric pressure is less than one percent of that at sea level on Earth. This means that liquids like water (and blood, which consists mostly of water), will boil at much lower temperatures than what we are accustomed to. Even in areas on Mars with above-average atmospheric pressure, water boils at 10ºC. These environmental conditions necessitate wearing protective gear whenever astronauts are outside the work station, and the challenge will be to make space suits more durable and less cumbersome than those we saw in the landing on the moon.

New NASA spacesuit from January 2017. Credit: NASA/Cory Huston

Life on Mars

The initial missions to Mars will be aimed at learning how to live and survive on the distant planet. They will probably include setting up a residence and a laboratory, both of which must primarily shelter the crew from the temperature changes and radiation, and provide the means for self-sustenance.

In 2016, NASA selected six companies to design a prototype for the working and living facility, giving them two years to perform the research and build the first model. The structure would have to address critical life-protection issues, such as safety measures, air supply, energy, etc.

Risk factors abound; researchers from the University of Edinburgh in the UK have recently discovered that there are more dangers in radiation than previously thought. These dangers stem from chemicals originating in Mars’ surface, which intensify the effect of radiation, which is already high due to the thin atmosphere. 

In a laboratory study, researchers exposed these chemicals to radiation similar to that found on Mars, showing that exposure to these radiated chemicals resulted in vast bacterial cell death. A possible solution to this problem is building the living quarters underground, but this would require sending heavy machinery from Earth, which is not currently feasible. In the past, researchers suggested launching unmanned missions with robots before human arrival to the planet, in order to build the required infrastructure for the manned mission. 

Beyond safety, the companies developing the living quarters will also have to address the issue of maintaining the crew members’ mental health. The mission to Mars, including the trip itself, will be a very long one. During the whole time, crew members inhabit small, crowded spaces. Research shows that people may develop claustrophobia, or fear of closed places, and other psychological disorders following an extended period in space and in confined spaces. In order to minimize the risk, the living and working environments will have to be not only compact and light-weight, but also provide crew members with sufficient personal space and privacy.

Simulations conducted on Earth are attempting to decipher the possible effects of a long stay in space on humans. For instance, every year, the Mars Society, a non-profit organization that aims to promote research about Mars, holds simulations in a special isolated building in the Utah desert in the U.S. Israeli graduate student Roy Naor participated in one of the latest simulations.

NASA is also attempting to improve their understanding of the effects of a long stay in space on astronauts. A twin study, which began in 2015, is testing how spending one year in space influenced the astronaut Scott Kelly, by comparing him to his twin brother, who is also an astronaut and stayed on Earth during this time. Aside from psychological effects, researchers are also testing changes in gene expression between the twins.

Idea for a living environment in space. Credit: NASA

Self-sufficiency in a foreign world

Longer missions to Mars and establishing a permanent colony hold additional challenges. One of the most complex tasks is food supply – as relying on a constant supply from Earth is not practical, the new Martians will have to grow their own food in specialized greenhouses.

They will also need a constant supply of medications; one solution to this is self-production at a lab on Mars itself. Researchers from the Netherlands have recently developed an efficient and simple method for utilizing solar energy to carry out chemical reactions. The researchers created artificial silicon leaves that absorb different magnitudes of radiation, but then use just the amount of radiation required for the chemical reaction, emitting the extra. This may allow the settlers to produce drugs and even chemicals that can be used in agriculture. 

The first manned NASA mission to Mars is only planned for the 2030s, about 20 years from now, and it seems the list of questions and difficulties just keeps getting longer. Even now, it is clear that the first passengers are not in for a relaxing vacation, but rather a journey of survival and discovery – just like the great explorers, but with different scenery. The main question that arises is whether the allocated time is sufficient to develop new technologies and gain deep knowledge about Mars that would enable us to handle the many challenges in store.

A recently posted video on the AsapSCIENCE YouTube channel provides a short and mostly ominous overview of the dangers that await travelers to the red planet:

Translated by Elee Shimshoni