10.11.2019
Humans have long fantasized about Mars exploration and colonization. That dream could become a reality now that NASA has plans to put astronauts on the Red Planet by 2030. Simply transporting people across the 34 million miles of space that exists between Earth and Mars presents one of the biggest challenges. But upon arrival, humans will have to overcome enormous obstacles to create a life on Mars — a desolate, frigid and inhospitable rock.
Water Locked in Rocks and Sand
Water is essential to human life on Mars, but the Red Planet doesn’t contain water — or does it? Evidence dating back to the 1970s says otherwise. When the Mariner 9 and Viking space probes first sent images of Mars back to Earth, there were signs of water.
Some of the most recent clues come from researchers at the National Institute for Astrophysics in Italy. In 2018, they published a study in Science reporting that they had found a lake about 12 miles across and hidden about a mile below the south pole of Mars. In the same year, scientists from the U.S. Geological Survey said they’d found eight regions on Mars where erosion had uncovered large cross sections of ice deposits between one and 100 meters below the planet’s surface. A year later, scientists analyzing data from NASA’s Mars Reconnaissance Orbiter said they located layers of ice and sand buried a mile beneath Mars’s north pole, reports the American Geophysical Union.
The technology to extract water locked in Martian soil doesn’t exist yet, but NASA hopes to bridge that gap through its Mars Ice Challenge, an annual competition aimed at university engineering students. Ten finalists are selected to compete at Langley Research Center in Virginia, where they show off their prototypes designed to retrieve water from simulated Martian subsurface ice. A team from West Virginia University won the 2019 competition for their prototype, called Mountaineer Ice Drilling Automated System III, which was able to identify, map and drill through a variety of rocky and icy layers and then extract water from an ice block.
NASA has also formed partnerships — including a partnership with the Australia Space Agency — to advance mining technologies for use in space. And in July 2019, NASA along with the University of Central Florida and Honeybee Robotics showed off a prototype spacecraft the size of a microwave oven called The World is Not Enough (WINE). It’s designed to mine soil on asteroids, extract water from the soil and use it to generate steam to propel itself to its next mining target. The technology could be adapted to harvest water for Mars exploration.
Thin Atmosphere
One of the most important attributes a planet needs to support human life is an atmosphere. Unfortunately, a very thin one clings to Mars and it’s made up of all the wrong gases.
According to NASA, our neighbor’s atmosphere:
- Is mostly composed of carbon dioxide (95.3% compared to less than 1% on Earth).
- Has barely any oxygen (0.13% compared to 21% on Earth), which humans need to breathe.
- Contains very little nitrogen (2.7% compared to 78% on Earth), which plants need to survive.
Life on Mars would be impossible without a hefty supply of air.
On top of that, the atmospheric pressure on Mars is quite low — just 6.1 millibars compared to Earth’s 1,013.25 millibars. Pressure is critical to life on Earth. Without it, tiny pockets of air trapped inside a person’s body would expand. Eardrums would rupture and water in the body would boil, according to the Institute of Physics. Astronauts wear pressurized suits to survive in space, and they’d have to wear them on Mars, too, or live in a pressurized habitat.
The thin atmosphere lets any heat from the sun escape into space. As a result, Mars is very cold with temperatures that dip to as low as -285 degrees Fahrenheit, according to NASA.
People have proposed engineering an atmosphere on Mars that would produce the necessary gases and warm the planet. So-called terraforming involves stimulating greenhouse gases, including carbon dioxide and water vapor, that already exist on the planet to rise into the air. But a 2018 study in Nature Astronomy found that the planet did not have enough of these elements to create an atmosphere that would sustain human life on Mars. For the time being, astronauts traveling there will need to bring all of the life-supporting systems with them.
High Levels of Radiation
Harmful radiation permeates the cosmos. Our sun and other stars are essentially fusion reactors that spew abundant amounts of electromagnetic energy, including X-ray and ultraviolet radiation. The sun, as well as other intensively energetic objects like quasars or the center of galaxies, also emit high-energy protons, atomic nuclei and other particles that can cause radiation sickness, adversely affect a person’s central nervous system, increase one’s lifetime risk for cancer and cause degenerative diseases.
Our planet’s strong magnetic field forms an invisible barrier against such radiation and diverts most of these electrically charged atomic fragments back into space. Any strays are absorbed by our planet’s thick atmosphere. Astronauts outside this protective bubble are at risk. On a mission to Mars, they could receive radiation doses up to 700 times higher than on Earth, reports the European Space Agency (ESA).
The agency is taking steps on Earth to build technologies that mitigate that exposure. They’re working with particle accelerator labs to recreate the dangerous amounts of cosmic radiation found in space and build and test shields that can protect against it. They have also planned to send radiation sensors on NASA’s upcoming Orion test launch to track exposure during the mission to the moon.
In the meantime, astronauts onboard the International Space Station recently conducted an experiment that showed they could successfully mix cement in microgravity, reports Astronomy. The idea is that one day people could use Martian soil to build habitable structures from concrete, a sturdy, protective material already used on Earth at nuclear facilities to shield people from radioactive exposure.
Future Mars exploration missions will present scientists and astronauts alike with a host of problem that will challenge human survival. Accessing water, dealing with a frigid planet that lacks oxygen and coping with dangerous levels of radiation are among the biggest hurdles to overcome. But as humans persists toward the moon with an eye on Mars, they will learn to adapt, as they always have, and find new solutions to the problems facing them over the next horizon.
Quelle: Northrop Grumman