Accident on Mars

A game for amateur astronauts

“One small step for man, one giant leap for mankind.” In 1969, with these words, the first human set foot on a foreign celestial body. More than 50 years later, astronauts are striving for an even more distant destination: they want to be the first to set foot on Mars. But any mission to the red planet needs to be extremely well prepared. What might that preparation involve? Among other things, NASA uses a space game to help its astronauts to prepare. This game deals with a crash landing on the moon. The participants have to decide which of the things available on the moon are most important to them. Top of the list of answers is “oxygen”. You cannot survive without it. But conditions on the red planet are completely different from those on the moon. So let’s move the space game on a bit further and relate it to Mars. Join in!

Planets of the Solar System

The requirements

  • A crewed mission to Mars, which in 2025 (SpaceX program) will be stationed on the red planet to work on creating a magnetic field to shield the planet from solar winds.
  • Having landed, we head for the ground station, where the major scare is revealed. During the approach, one of the two oxygen tanks for the stay on the station was hit by space debris and destroyed.
  • A replacement can only be provided from Earth – a space shuttle carrying the fuel for the return journey could also supply the oxygen. But it will take ten months. That’s how long an unmanned probe took to reach Mars in 2007. The available oxygen supply is only sufficient for five months.
  • Mars is a barren planet; water probably exists beneath the ground and at the poles, although it could be extracted.
  • The Mars station still has sufficient food for five years.
  • The atmosphere on Mars consists of 0.25 percent oxygen, but almost 96 percent carbon dioxide (CO2).
  • The first task is to extract our own oxygen so that we can survive until the replacement tank arrives.

Three options are open to us, but time is running out. Every day is crucial if we are to stay on schedule.

NASA Mars Rover

Option 1: An old Rover

In 2020, NASA sent a Mars Rover to the rocky planet. This was designed to search for evidence of life or water, analyze the rock strata and determine whether it is possible to extract oxygen from the atmosphere of the red planet. On board was the Mars Oxygen ISRU experiment, MOXIE for short. Developed by researchers from the Massachusetts Institute of Technology, this instrument can split carbon dioxide into carbon monoxide and oxygen. In principle, MOXIE works like an inverted fuel cell. CO2 is absorbed from the air and heated to 800 degrees Celsius to compress it.

Once that has been done, voltage is applied to a cathode and an anode, which separate the carbon from the oxygen. The result of this electrochemical reaction is pure oxygen. The problem is that MOXIE is only a test instrument, hardly larger than an automobile battery. The rate of production is not enough to supply even one person. A fully functioning plant would have to be built on the basis of the model, and that must happen within two years. However, the Rover is not far from the station and the only raw material needed would be carbon dioxide. This is abundant in the atmosphere. MOXIE has another advantage: the gases produced during the reaction can be used as rocket fuel. This would mean less fuel would need to be brought from Earth to Mars, making the rocket lighter and enabling it to reach the planet sooner. It is a chance. After all, MOXIE can make the air usable sustainably, almost like a tree. This leads to the second idea...

Option 2: Artificial leaves

The space station contains one extremely efficient energy source: artificial leaves that produce hydrogen from carbon dioxide. This can be burned to produce energy. The energy producers imitate the photosynthesis of a natural leaf. This means they produce oxygen as a waste product. The leaves replicate the structure of their biological models. A semiconductor film made of silicon threads separates water oxidation and energy generation from light. In one process, the water is split by a cobalt alloy, producing oxygen and hydrogen protons. The artificial leaves are ten times more effective than their natural counterparts. Together with the existing oxygen reserves, the 15 leaves in the laboratory would be sufficient to last for four years. What’s more, the leaves would be already on-site and ready for use. There is just one problem. To extract carbon dioxide from mixtures of substances, the artificial leaves need a protective cover. This consists of a semi-permeable membrane and water. The latter is difficult to find in the unearthly red desert. On Mars, there is nothing but sand, rocks and the sky above. A comet flies by. There is one last idea...

Energy efficient space station

Option 3: A gold blanket

This is another way of splitting carbon dioxide into oxygen. To do this, it requires enormous impact velocities. Researchers at the California Institute of Technology discovered that if CO2 is allowed to collide at high speed with a non-reactive material, its molecular structure can bend. This causes the oxygen to separate from the carbon. The researchers used this to explain the occurrence of oxygen in the outer shell of comets. Carbon dioxide is normally a linear molecule. On impact, one oxygen atom initially comes into contact with the impacting object, followed by the carbon residue. In most cases, the oxygen is blasted off and carbon monoxide is formed. However, in some cases the molecule remains intact and bends. The oxygen particles draw closer together and form a bond. This results in the bonded oxygen being released from the carbon. The necessary acceleration can be achieved in the laboratory. The gold from the shuttle’s thermal blankets would provide a low-reaction impact material and nothing other than carbon dioxide would be needed. However, the yield from this type of oxygen is incredibly low. Only around one to two percent of the CO2 atoms bend and release oxygen.

Innovative filters are essential

For one of these solutions to be successful, efficient filter solutions are essential:

  • Carbon monoxide and other harmful gases are produced as a waste product; these have to be adsorbed from the air before a person can breathe the oxygen produced.
  • The atmosphere of Mars consists of 96 percent CO2. The remainder needs to be filtered so that the machines run better.
  • In the laboratory, cleanroom quality is necessary to ensure that the leaf does not need water when pure CO2 is supplied. Creating a cleanroom requires filters.


None of the options offers any certainty of success. The best chance lies with the artificial leaves. The Rover first needs to be reached. What’s more, it is unclear whether the know-how and time are available to reproduce MOXIE on a large scale. This would therefore be a long-term solution.

The gold blanket will work without the addition of other substances, but oxygen production is so low that not enough air can be produced before the existing reserves are exhausted.

Rocket launch

In contrast, the leaves will lead to certain success as long as there is enough water. They are already being used in the laboratory, so they still have water available and are already producing oxygen. Congratulations if you reached the right conclusion – you are ready for take-off.