5 mins read 28 Aug 2021

Earth to Mars - what’s on the menu

How do you sustain a crew on a five-year return trip to Mars with no resupply options? CSIRO scientists are working on a smart biofactory that will produce nutrients on-demand using microbial systems with brewers’ yeast and microalgae. 

Crew members aboard the International Space Station unpack newly delivered fresh fruit and other goodies in October 2019. From left are NASA flight engineers Jessica Meir, Andrew Morgan, and Christina Koch with ESA Commander Luca Parmitano. Credit: NASA

NASA’s Artemis program is set to send the first humans back to the Moon in just a few years time, with ambitious goals for the far longer trip to Mars set for the 2030s. So where does the food that astronauts require come from on these long-duration flights? Lifting it off the Earth would pack way too much weight into the rocket, and be non-cost-beneficial. During the Space Shuttle mission flights, NASA averaged 1.7 kg of food per day for astronauts and flights to the International Space Station (ISS). For a five-year return trip to Mars, that would add up to around 3,000 kg of food per person. 

Not only does that make it challenging in terms of additional weight when launching and powering a spacecraft, but how will radiation in space affect the long-term storage of the food? 

Luckily, scientists from Australia's national science, CSIRO, have been working on ways to ensure astronauts can receive all the nutrients they need while also looking at how other environmental factors such as microgravity and lack of sunlight impact both wellbeing and human body functions.

Dr Regine Stockmann and her team at CSIRO are working on a smart space biofactory. The system makes specific nutrients on-demand in space using novel synthetic biology approaches with microbial systems using yeasts or microalgae.

By making the nutrients in space, they are not included in the payload to be transported into space. The smart biofactory will produce nutrients such as fatty acids, protein and vitamins in the microbial biomass using brewer’ yeast, spirulina and others. 

While still in the early phases of their research, the smart biofactory will use readily available inputs such as radiation energy, CO2, brackish water, and even urine to produce nutrients to secure nutritious food sources. 

“We have a multidisciplinary team of scientists involved in developing the smart biofactory,” explained Dr Stockman.

“The heart of the biofactory are our microorganisms such as brewers’ yeast. Our molecular biologists use metabolic engineering and synthetic biology approaches to provide a holistic approach to optimising the expression of nutrients in the microbial biomass."  

“Selection and determination of the required nutrients is being informed by nutritionists and the biomass will be formulated into foods by our food technologists.  Engineers are designing the fermentation system so that mixing and nutrient supply for the microorganisms is optimal even under microgravity conditions.”

Effects of radiation on food

Mizuna mustard plants grow inside plant pillows in the Vegetable Production System, also known as Veggie, on the International Space Station. Credit: NASA

Long-term space travel such as missions to the Moon and Mars brings additional challenges beyond food production. Food for extended space missions needs to withstand radiation in space without losing its quality not only in terms of nutrients but also appeal. Dr Stockmann’s team is also researching the impact of radiation on food storage in space. 

There are two types of radiation in space, galactic cosmic rays and solar rays. Working with the Australian Nuclear Science and Technology Organisation (ANSTO) nuclear reactor facility in Sydney, similar types of radiation can be created to test the exposure to radiation on stored food. 

And here is where the baby formula steps in. Chosen for its rich source of nutrients and protein, ANSTO irradiated the baby formula at various levels to monitor how the quality may change over time. After ten days of radiation exposure, both the colour and vitamin content of the samples changed.  

“That research is aimed at understanding the shelf life of any foods. It could be brought from Earth, grown in space in glasshouse type structures or grown/cultured in the biofactory,” said Dr Stockmann. 

With the Artemis mission to send people to the moon only a few years away, followed by Mars by the 2030s, when could we see the practical application of the smart biofactory in space?

“We think we could have biofactories ready in about 5 years time.  It would be great to have at least a demonstrator in the mission to Mars,” said Dr Stockmann. 

“Initially the biofactories would probably be used in conjunction with growing food in space, however, fermentation methods and hardware are becoming more scalable and the entire nutrition demand of Astronauts may be met in future (by the biofactories).”

Space food has come a long way since the early NASA missions of baby-food consistency nutrients squeezed from tubes or semi-liquids sucked from pouches. Now the astronauts onboard the International Space Station enjoy a variety of meals from a selection of over 100 items on the menu. Whilst resupply is no longer such a big issue, in the future and with more lengthy journeys, food supply will have to go back to the drawing board. 

“If we're going to start exploring and start becoming more Earth-independent, we need to start understanding how we produce the foods and not just take foods with us,” said Grace Douglas, lead scientist for NASA's Advanced Food Technology at Johnson Space Center, in an episode of Houston, We Have a Podcast.