What does it take to live on the Moon or even Mars? Erin Tranfield suggests an interdisciplinary teaching activity to get your students thinking about this – and learning a lot of science along the way.
Planet Earth is able to meet the basic living requirements for trillions of organisms, including humans. The oxygen we need is in the air around us, the atmosphere protects us from radiation, drinking water can be found in rivers and lakes, and food can be readily found in most places.
On Earth, cycles exist where one species’ waste products are used by another species, so that the waste products do not build up to high levels: an example of this is the complex carbon cyclew1 in which oxygen and carbon dioxide are alternately produced and used by plant species and animal species.
However, in space, none of these requirements for human survival are met. Therefore, to live and work in space, we have to take with us everything we need, and we need to devise ways to recycle or dispose of the waste we produce. We must do this while limiting the weight of material taken to space and building in backup safety equipment (redundancy).
Weight must be minimised as transport into space is extremely expensive. It currently costs about 17 000 USD to lift 1 kg to the International Space Station (ISS) (based on an average launch cost of 450 million USD and shuttles carrying an average of 26 000 kg of cargo plus astronauts). It will cost much more to take 1 kg to the Moon or to Mars.
At such a great expense and with the inherent difficulty of each mission to space, every kilogram needs to be justified. Furthermore, backup equipment is required for every life-support system in space. Currently, on the ISS, there are three levels of this redundancy, just in case the primary system fails and a backup system is needed.
Getting your students thinking about habitat design on the Moon or Mars can be a good way to consider the challenges of living and working in space as well as illustrating the critical role that the cycles on Earth play in the survival of all organisms. It is an activity suitable for students of all ages (see the suggestions for different age groups, below).
The introduction to the activity will take about 2 hours, with at least a further 2 hours to design the habitat, depending on its complexity. To build the habitat could take 5-15 hours, depending on how many students are involved and how complex a habitat they are building. If the students are really enthusiastic about the idea, they might want to invest even more time.
When you have finished, send a photo of your completed space habitat to email@example.com and we will publish a selection of the photos on the Science in School website.
Begin by asking your students to consider what humans need to stay alive and work efficiently on Earth. How could we meet these needs in space? And how can we build space facilities with the highest efficiency, lightest weight and longest durability? See the box below for many ideas, together with links to more resources, including many from the European Space Agencyw2. Further background information can be downloaded as a PDF or Word® documentw3.
Now the students can begin to design and even build their own space habitat. First, they will need to decide whether to build their habitat on Mars or the Moon, because the design requirements will differw4.
They should bear in mind that the Moon has greater temperature changes and no atmosphere for protection but is closer to Earth. Mars has more moderate temperature changes and an atmosphere, but it is much further away from Earth, thus a Mars habitat will need to be much more independent.
What do we expect for our everyday life on Earth?
Many of our requirements in a space habitat would be similar to those on Earth, but some would be specific to the new environment.
Many of these considerations were also important in the design of the ISS. For more details, see Hartevelt-Velani & Walker (2008).
Any crew on a long mission, for example to Mars, will be isolated from their loved ones and confined in a small space with other crew members. Training in conflict management is crucial, as is enhancing our understanding of how humans respond under stress, in a confined space over long durationsw15.
The mental state of each individual is extremely important, as it will affect the group mental state and ultimately even the overall mission success. It is therefore important to ensure good mental support for the crew.
On Earth, humans need a sense of mental well-being including interactions between people to be happy and productive. To achieve this, in addition to the points listed above, a space habitat needs to provide:
To learn about life on board the ISS, for which these considerations are important, see also Hartevelt-Velani et al. (2008).
When a space habitat is designed, it is important that it should be:
How can we meet the requirements of a space habitat under the constraints that are imposed? This is done by:
The author would like to thank Scott Hovland from the European Space Agency for valuable comments and advice.
Richardson JT (2000) Improved Sabatier reactors for in situ resource utilization on Mars. In Institute for Space Systems Operations - 1999-2000 Annual Report. Pp 84-86. Houston, Texas, USA: University of Houston. www.isso.uh.edu/publications/A9900/mini-richardson.htm
The primary-school ISS education kit includes activities such as building a model of the ISS from recycled household materials, planning the amount of water and weight of other materials to be taken onto a space mission, or creating an astronaut menu. See: www.esa.int/SPECIALS/Education/SEMN3A5KXMF_0.html
The lower-secondary-school ISS education kit offers videos, background reading and interactive online materials about building the ISS, life and work on board, as well as classroom activities such as investigating and filtering your local fresh water, designing a space station bathroom, studying how the environment affects materials, or designing and constructing a glove box like the one used for experiments on board the ISS. See: www.esa.int/SPECIALS/Education/SEMTBS4KXMF_0.html
Warmbein B (2007) Down to Earth: interview with Thomas Reiter. Science in School 5: 19-23.
Wegener A-L (2008) Laboratory in space: interview with Bernardo Patti. Science in School 8: 8-12.
Williams A (2008) The Automated Transfer Vehicle – supporting Europe in space. Science in School 8: 14-20.