Should We Send Humans to Mars?

Universe Today has explored the potential for sending humans to Europa, Venus, Titan, and Pluto, all of which possess environmental conditions that are far too harsh for humans to survive. The insight gained from planetary scientists resulted in some informative discussions, and traveling to some of these far-off worlds might be possible, someday. In the final installment of this series, we will explore the potential for sending humans to a destination that has been the focus of scientific exploration and science folklore for more than 100 years: Mars aka the Red Planet.

Dr. Jordan Bretzfelder, who is a Postdoctoral Fellow in the Department of Earth, Planetary, and Space Sciences at the University of California, Los Angeles (UCLA), shares her insights on the viability of sending humans to Mars and how we should do it. So, should we send humans to Mars?

“Yes, I think there is immense value in sending humans to engage in scientific exploration on Mars,” Dr. Bretzfelder tells Universe Today. “Humans can make quick decisions about sampling and data acquisition and can move around certain obstacles and terrain with more ease and freedom than many types of robotic vehicles. This would also provide opportunities to study and develop technology to facilitate future planetary exploration.”

Countless robotic pioneers have explored the surface and atmosphere of Mars in incredible detail and continue to teach us whether Mars once had—or currently has—life. However, humans could provide an extra level of exploration since they won’t be hindered by waiting for instructions from Earth ground controllers, which can take anywhere from 5 to 20 minutes one way. If something goes wrong, human explorers can make on-the-spot decisions to find solutions, whereas robot explorers are faced with waiting for engineers back on Earth to find solutions, followed by sending instructions, and more waiting. Regarding technological advancements, a human mission will undoubtedly teach us how to live and work on Mars, and this includes testing shelters, food, bathroom facilities, and even combating the mental fatigue from being so far from Earth for a prolonged period. All things considered, what are the pros and cons of sending humans to Mars?

Dr. Bretzfelder tells Universe Today, “Pros are as above, and many examples of the benefits of humans in the field can be found in the history of the Apollo missions; instances where certain scientifically valuable rocks were collected due to the quick thinking and judgement of the astronauts. Cons include the difficulties involved in keeping astronauts alive and safe on a distant and environmentally complicated planetary surface. Additionally, the possibility of accidentally introducing terrestrial microbes to Mars is a potential risk.”

Whether it’s a robotic or human mission, NASA’s Office of Planetary Protection is responsible for ensuring that microbes don’t hitch a ride and contaminate extraterrestrial environments that we wish to explore, but especially to protect us from any microbes that could potentially be brought back to Earth.

Regarding the ongoing robotic exploration of Mars, there are presently seven active Mars orbiters from several nations teaching us more and more about the Red Planet and unlocking its secrets. On the surface, there are currently three active missions: NASA’s Curiosity and Perseverance rovers, and China’s Zhurong rover. Past successful surface missions include NASA’s Viking 1 and Viking 2 landers, Mars Pathfinder, Spirit and Opportunity rovers, Phoenix lander, and InSight lander. From marsquakes to finding evidence for past surface liquid water, each of these missions spent years unlocking the secrets of Mars, both above and below the surface. But what additional science could be conducted by a human mission compared to a robotic mission?

“As above, humans (within limits based on their suits and other equipment) have the ability to navigate terrain that may not be suitable for a rover or helicopter,” Dr. Bretzfelder tells Universe Today. “They also can make real time decisions in the field about sampling etc., meaning there is less delay in waiting for signals from mission control to guide the rovers. Humans are also very adaptable to changing conditions and can respond quickly to address any issues or unexpected situations during a mission.”

In terms of an actual human habitat on Mars, countless images, videos, movies, and television shows have depicted a human habitat on the Martian surface, with very little depiction of a human habitat below the surface. While this depiction might be for aesthetics, a habitat on the surface would provide ideal surveying and sampling conditions, along with far better communications with Earth. However, a habitat on the surface would also expose the crew to dangerous amounts of solar radiation since Mars does not possess either an ozone layer or magnetic field like the Earth, both of which protect us from solar storms and other cosmic rays.

In contrast, another type of human habitat could be below the surface, with past studies identifying the use of lava tubes for human settlements to shield them from the harmful solar radiation. However, any surface ventures could become tedious, along with communications with Earth becoming more complicated, even if a communications array was above-ground. Therefore, if humans were to travel to Mars, should it be above the surface or below?

Dr. Bretzfelder tells Universe Today, “An above surface mission, similar to the Apollo and upcoming Artemis missions would be the most feasible given the technology available and would limit impact to the Martian surface by simply operating above ground rather than excavating below ground. Samples or cores taken from depth may be scientifically valuable though.”

This discussion comes as NASA prepares to send humans back to the Moon as part of its Moon to Mars Architecture while SpaceX develops its Starship with the goal of sending humans to Mars, someday. China announced plans in 2021 to send their own astronauts to the Red Planet in 2033, with follow-up launches occurring every two years afterwards. Additionally, NASA has the goal of sending humans to Mars sometime in the 2030s.

“It is an exciting time to be able to seriously consider this type of exploration, and as we return to the Moon, we will likely learn valuable lessons to enable human exploration of Mars,” Dr. Bretzfelder tells Universe Today.

Will we ever send humans to Mars? Will such a mission achieve greater scientific objectives than the myriad of robotic missions sent to the Red Planet, and what could a human mission to Mars teach us about living and working so far from Earth? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!