For a normal person, running a marathon might be considered to be extremely exhausting. However, for our analog astronauts wearing the Aouda.X space suit, just tying shoes can be exhausting work!

My research project, as part of my Master’s degree in Space Physiology from King’s College London, set out to find just which tasks proved to be the most difficult during the MARS2013 analog space mission. While the MARS2013 mission was over a year ago, it still provides large amounts of data which can be analyzed in order to identify the workload of specific tasks the astronauts completed during their time in Morocco.

Biomedical monitoring is a key feature of the Aouda.X space suit. It not only allows the medical support team to ensure the astronaut is comfortable and safe, but it also gives real time measurements of the astronaut’s heart rate and air flow.
We chose to select 2 key variables of the 34 total that the Aouda X is able to monitor. Heart rate is used as a good indicator of exercise, as even simple exercise can raise a person’s heart rate. The rate of oxygen used by the body is also a good indicator of how hard the body is having to work to provide enough oxygen to the muscles. As there aren’t any direct measurements of oxygen consumption within the suit, so we chose to evaluate the amount of carbon dioxide produced by the astronaut.
By combining the data from these two variables with a questionnaire regarding the well-being of the astronaut, we were able to identify 7 tasks which the astronaut performed daily. These repetitive maneuvers were part of the DELTA experiment, which set out activities which the astronaut might perform were they making a surface exploration of Mars. They included things such as setting up a tripod, carrying sand bags, taking rock samples and so on.
Our results found that activities involving long bouts of walking, and load-carrying caused the greatest workload for the astronaut, resulting in working at 90% of their maximum heart rate. In the sandbag carrying experiments in particular, the carbon dioxide rates increased, indicating that the astronaut was breathing heavily.
A surprising result was that fine motor skill tasks, such as repairing an object, were quite difficult for the analog astronaut. They had to work against the bulky space suit gloves, and the pressure of the exoskeleton to maneuver small parts. This resulted in high heart rates, up to 75% of their maximum heart rate. This meant it was on par with running for an unsuited individual. Talk about hard work while just standing still!
Identifying which tasks provide the most workload on the astronaut, allows the Mission Planning team to space out activities which the astronaut will find exhausting, or strenuous. It can also be used to identify where a rest period might be useful, and allows the biomedical team to monitor the astronaut more carefully during these periods.
Our research found that all three variables should be used together to identify the workload on the astronaut. The analog astronauts may have an interesting job that many people dream about – but they certainly have to work hard on the job!

About the author:
Taylor Moyer was an OeWF intern this summer.
During her intership she was researching the topic described above for her Master Thesis in Space Physiology and Health at the King’s College London, United Kingdom