Many people believe that it’s preferable to send robots to Mars instead of humans because it’s cheaper and doesn’t jeopardise human lives. However, if settlement is our aim – and it should be – we must send people. In fact, even if exploration and science are our only goals, we can still achieve much more with humans.
In recent years we’ve witnessed a number of tremendous successes with robotic exploration of Mars. This effort has moved us significantly forward in our scientific understanding of Mars, how sensors and actuators function on Mars, and how to land stuff on Mars. The Mars Exploration Rovers Spirit and Opportunity have been a fascinating triumph: with an initial planned mission duration of just 90 sols (a “sol” is a Martian day, about 24 hours and 40 minutes), Spirit lasted about seven years and Opportunity is still going strong and making discoveries after 10. The landing of the Curiosity rover in 2012 was also a spectacular achievement in terms of engineering, being the largest mass (900kg) ever soft-landed on Mars.
Although much can and has been achieved with robots, humans on Mars will achieve much more. Although robots may not require air, water and food, humans offer greater cognition, dexterity, flexibility, adaptability, creativity, independence and efficiency; at least for now. The robots we’ve sent to Mars are in fact semi-autonomous, remote-controlled machines, directed by people on Earth. Astronauts on the surface of Mars will be guided by experts on Earth, but they’ll also have the freedom to indulge their own curiosity, pursue individual interests, and organise their own time and activities to a large degree.
Whether humans or robots go to Mars, the goal is for humans to gain knowledge and experience of Mars. Robots are simply a tool to achieve this, and are therefore effectively the “middle-man”. But the middle-man can be removed in order to get a better result. With humans on Mars, the experience of Mars can be obtained more directly and much more efficiently.
Robotic exploration proceeds extremely slowly and cautiously, partly because of the time delay in communications, but partly because these machines cost millions or billions of dollars to develop and send to Mars, and are therefore designed to move very slowly to ensure their survival. Every action must be considered and approved by a team on Earth before being sent to the robot. Every instruction takes between four and 20 minutes to reach Mars, and every photo and piece of data collected takes at least the same amount of time to be sent back to Earth. These machines have limited cognitive and physical abilities; if one becomes stuck in soft soil, such as what happened to Spirit, sometimes nothing can be done to get them out.
Humans will also move cautiously on Mars, but they can still move a lot faster while being careful. They can do many more things, both cognitively and physically, they don’t have to wait for instructions from Earth for every little decision, they can react in real time to unexpected events or discoveries, and if they get stuck in soft soil (for example) they can figure out a solution themselves or one of their crewmates can help them. A group of co-operating humans is functionally equivalent to a group of networked bipedal dexterous robots with strong AI. Perhaps in 20 to 40 years we can send machines to be that; or, we can just send people now.
Humans on Mars will not only deliver new information about Mars, but also the experience of Mars. They’ll be able to communicate with people on Earth in a way that robots simply cannot; they’ll be able to share emotions and sensory experiences that robots can’t have. This empathy will engage humanity with the Martian adventure and bring Mars within the sphere of our collective experience. The gates of human imagination and ingenuity will open, stimulating a flood of new ideas, missions, projects, experiments, businesses and plans, leading us directly into our dream of becoming multiplanetary.
Robots will always be part of our life on Mars. But we must send people, to more rapidly increase our knowledge of Mars, to bring Mars within the human sphere, and to commence a process of settlement.