Humans vs Robots for Space Exploration

Last week the European Space Agency achieved an important milestone in the history of Space Exploration with the first landing on a Comet. The lander named Philae was released from it’s parent spacecraft Rosetta and seven hours later touched down in the surface. Due to some complications the spaecraft ended up bouncing and landed two additional times coming to rest in a location that resulted in it not getting nearly enough sunlight to recharge the batteries.

There is a possibility that as the Comet travels around the Sun there may be more sunlight available that would allow the lander to have enough power to start up again but there is no guarantee of that.

Since this happened there has been quite a debate about the advantages of robotic vs human exploration.

In this post we will explore the advantages and dis-advantages of each and why we believe there is an important place for each.

Robotic Missions

(A) The first and biggest advantage is the reduced overhead of providing for a human crew from Life Support, Food, Water, Waste Management, etc.

(A) Due to the lack of advanced space propulsion systems travel within our own Solar System takes a long time. Robotic missions to deeper into the Solar System handle this by designing the necessary protections and in the case of recent missions long hibernation periods.

(A) Can visit places that are either too extreme for human’s or we don’t know enough about yet to risk human visitors.

(D) Can only adapted to scenarios that have been pre-programmed and then only depending on the abilities given to the robotic mission. Take for example the Philae lander, it ended up in a location that wasn’t ideal for the vehicle and doesn’t have the capabilities to address that itself.

(D) If something breaks it may be impossible to repair it depending what capabilities where built into the spacecraft.

Human Missions

(A) Can perform a much wider range of experiments and make decisions on what to sample.

(A) Can quickly adapt to situations as they happened rather than having to communicate back to Earth and waiting for new commands. For example on the way to Mars come across a Comet or Asteroid they could adapt the mission to observe it or even visit it depending no impact to overall mission.

(A) Can make repairs and upgrades during the mission if something goes wrong which is inevitable with anything and with the advances in 3D printing new parts could be created by the crew and replaced as they are travelling.

(D) Require a lot of resources, need to have enough for the whole mission plus some contingencies for emergencies. Getting all these resources into space either from Earth or in the future from in-space mining etc will cost money and add risk for each launch needed.

(D) We know the effects weightlessness has on the body from research done so far on the ISS and other space stations. For longer duration missions we would need to ensure this is handled, and depending on the mission, and it’s length there could be different ways to handle this.

(D) If something catastrophic happens there may not be abort scenarios that would allow the crew to survive or even get back to Earth. A mission to Mars takes many months of travel when the alignment is optimal and could be significantly longer if not.


There are clearly advantages and dis-advantages to each, we believe that there are important places for both in the future.

Until such time as we have much faster transportation in space deep space missions are just too long for humans to do without spending vast amounts of money, therefore robotic missions are needed.

We also need manned missions to help us continue to learn about surviving in space.

Even in the future shown in Star Trek or other movies it is clear that a combination of Manned and Robotics is used for exploration.

We would love to hear your thoughts on the Human vs Robot discussion below in the comments.


3 responses to “Humans vs Robots for Space Exploration”

  1. Marshall Eubanks Avatar
    Marshall Eubanks

    In the past 50 years, we have conducted an experiment on human versus automatic exploration (of course, in both cases there are lots of people back home). These are the 10 year (or so) period of intense Lunar exploration (1962-1972), versus 50 years (so far) of automatic spacecraft exploration of Mars (1964-2014).

    The simple fact is we understand the Moon much better than we understand Mars. There are a number of reasons for this, besides the agility and intelligence of the Apollo crews. For example, human exploration, purely because it is expensive, justifies doing a lot of science all at once.

    Here is another consideration : intensive exploration is less likely to fall through. I will give one example – despite what you may read, the issue of the Viking biological experiments, and what they revealed, as never been resolved – or even addressed. It is hard to imagine that this wouldn’t be resolved in the first few days after “boots on ground” on Mars.

    The real question, to me, is how to make sure that the next human mission to deep space is not a one off, even after accidents where the crew is injured or lost, or conversely a brilliant success that makes it seem all too easy. We need to develop a deep space infrastructure, with human missions, robot missions, tourism, the whole bit, to gain enough critical mass to make support activities such as lunar mining and asteroid mining viable. That implies that the first boots on Mars, or at worst the second set, will be colonists, not visitors. If that can be done. then space will become a place for humanity to grow into, and all the rest will happen naturally.

    1. ChrisDMarshall Avatar

      Great feedback thank you.

      I agree we need a plan that ensures that we continue to move out beyond Earth. Unfortunately I fear that SLS and Orion will end up be cancelled before they can really get going due to the large cost, need cheaper but very reliable access to space to make it work.

      1. Marshall Eubanks Avatar
        Marshall Eubanks

        I agree with you about the danger. We may be fortunate in that there a some powerful Republicans in the House who really want the SLS to fly. The thing I like about ARM is that, if we can get astronauts into a high retrograde lunar orbit (HRLO), missions to Phobos open up, both unmanned (the ARM robot retrieval vessel could also to “grab a boulder” on Phobos, and bring it back) and with crews (energetically, getting a crew to Phobos is not much harder than getting one to HRLO – the travel time is rather longer, of course).

        So, I am (for the first time since 1980) actually rather hopeful about boots on Mars. If we can actually get ARM going, I think it could all flow in a fairly nice progression.

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