Guest Article by Professor Dr. Alexander Höhn / Colorado University Space Life Science Research Prepares Mankind for Long- Distance Space Travel
Dr. Alexander Höhn, adjunct Associate Professor of Aerospace Engineering Sciences at Colorado University, talks about the challenges and demands on life science research in space. Vaisala sensors have supported Dr. Höhn and his team on several projects that are simply out of this world.
Imagine the future with manned ature and humidity levels, as well as such spacecraft environmental con- flights to Mars and long-distance fluctuating carbon dioxide, oxygen and trols are often not adequate. space exploration missions. Long trace gas contaminant concentrations. Scientists at BioServe Space travel times make it impossible to Researchers often apply on-board Technologies at the University of pack all the clean water, fresh air and centrifuges to create artificial gravity Colorado have been using Vaisala’s food supplies to go. Instead, food and in space. With the help of centrifuges, carbon dioxide, humidity, and life support consumables, such as on-board space shuttle plant growth temperature sensors to control life water and oxygen, must be produced experiments can be performed both in science experiments both onboard on-site. Space life science research microgravity and at defined artificial Space Shuttle flights and at the Inter- helps mankind to realize the vision. gravity while keeping other variables national Space Station (ISS) since constant. This test set-up attempts to 1992 to regulate plant growth and Understanding the ensure that the effects of gravity can animal habitat environments. Effects of Microgravity be isolated from other factors. Project Risk Management Astronauts lose bone and muscle mass Controlled Environments during long space missions as they no in Space The costs of an individual space longer have to work against gravity. life science project are difficult to The same happens to plants and Life science and space biology estimate. Space flights are typically animals. Space life science research experiments, whether cellular organ- carried out for multiple purposes, thus explores how the lack of gravity, more isms, plants in small greenhouses, the launch costs are not carried by an precisely microgravity, affects living or rodents in their habitats, may individual research project. However, organisms. In addition, this research be severely affected by changes in building a miniature greenhouse that helps to develop advanced life support the environmental conditions. The is viable in space costs around one systems, including agriculture and carbon dioxide level in a spacecraft million USD. The typical weight of such water purification bioreactors, for long- can reach as high as 1%, even in the a greenhouse is approximately 100 distance space missions. presence of scrubbers that clean the kg. On the average, launching 1 kg of The only way to explore how air by selectively removing carbon goods costs around 10 – 20 000 USD. microgravity influences living organ- dioxide. Temperature and humidity Thus the greenhouse launch costs are isms is to go to space. In the small often fluctuate between +18 to +30°C around 1-2 million USD. sealed space capsules, however, the and 40-60 %RH, respectively, exclud- Space shuttles no longer fly, and effects of gravity need to be isolated ing even larger fluctuations during resupply and transport missions to from other environmental factors, such the pre-flight integration and launch the ISS now take place less frequently as the amount of light, varying temper- periods. For biology experiments, using smaller, rocket-launched space
24 194/2014 capsules. Thus careful planning is Due to the long history of reliable dioxide sensors. The humidity probe necessary to get the job done right operation and positive experience, HUMITTER 50Y was taken into on the first go. Regarding instru- excellent stability and ease of integra- service at the same time. Sensors mentation, Vaisala has taken away tion in the past, HMP110 sensors were from other manufacturers were also the risk by building products that again selected to control the payload tested but nothing else worked as are waterproof, environmentally that provides essential life support reliably. protected, can just be plugged in, and functions for the mice during the Over the years, the legacy they work. Vaisala sensors have never transport flight. The HMP110s will be sensors have been replaced with shown unexplained behavior in our used both for controlling humidity GMM220 series CO2 modules and applications. They have far exceeded through scrubbers, and to record tem- HMP110 humidity and temperature expected and certified calibration and perature and humidity for post-flight probes. However, the long retired stability levels and usable periods. science and engineering analysis. sensors are still functional and As there are plenty of things to worry Active carbon dioxide feedback continue to show reasonable read- about when planning a life science controls are not implemented as the ings after almost 20 years. This is experiment in space, Vaisala has been scrubbers are operational throughout quite impressive considering they chosen time after time to avoid unnec- the flight. have been exposed to environmen- essary risks. tal conditions far exceeding their A Long Journey with design envelope such as condensa- New Focus on Preventing Vaisala Sensors tion during unpowered payload Bone and Muscle Loss phases, high launch vibrations, as We found Vaisala in early 1990s while well as microgravity and spaceflight During the last 10 years the focus searching for small, rugged carbon environments. in space life science research using plants and space agriculture has been somewhat reduced, and higher emphasis was given to finding ways About the author to prevent bone and muscle mass Professor Dr. Alexander Höhn, born in Stuttgart, Germany, works as an loss due to microgravity. In order to Associate Professor of Aerospace Engineering Sciences at Colorado study this, a future flight will resume University. He holds a PhD in Aerospace Engineering Sciences and has US animal research aboard the ISS developed payloads for over 35 missions including NASA’s Space Shuttle and transport 20 mice to the Inter- Program, the International Space Station, as well as parabolic and sounding rocket flights over the past 25 years. The span of life science experiments national Space Station. A fail-proof ranges from cellular organisms and bioreactors to plant growth chambers as life support system with trustworthy well as small rodent habitats for space biology and medicine experiments. sensors is a necessity to ensure their survival during transport to space.
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