Our brave team of astronauts are going to have to eat, simple as that. Sure they won’t be able to enjoy a 3 course meal every night but they do still require energy to do stuff that food conveniently provides. Feeding 6-12 astronauts for 6 months is no easy feat (Not that any of this is proving to be particular easy but that’s space travel for you) but before we consider the solutions, let’s take a look at how much your average astronaut actually needs to survive.
Stayin’ Alive: How much food do we need?
Humans need around 8400kJ or 2000kcal to feel satisfied (1). That is a fair bit of energy but, personally, it isn’t the easiest thing to visualise. What better way to visualise the amount of energy we need than with some Martian chocolate? An average Mars bars contains about 228kcal/ 960kJ which means that one Astronaut would require around 9 Mars per day! That’s a whopping 1575 Mars bars for the whole journey for just one astronaut. If we then consider how many astronauts we will be sending to Mars we could be looking at anywhere between 9450 and 18900 Mars bars. Yum…
Now, another factor in all this is nutrition. Though some may like to disagree, Mars bars aren’t renowned for providing a healthy balanced meal with every bite. On a daily basis, we need to consume: 70g of fat of which 20 should be saturates, 260g of carbohydrates, 90g of sugar, 50g of protein, 6g of salt and a whole bunch of vitamins and minerals to ensure our bodies stay healthy (1). Not only do we have to contend with the energy demands of our crew but also the nutritional value of these meals. To top it all off, we also have to consider the limitations we have in terms of how much food can actually be carried.
In the vacuum of space, there is a bit of a limitation to how much food can be sourced from the surrounding area. However, astronauts have access to surprisingly varied menu (2) which can be prepared with ease whilst providing much of what astronauts need to survive (3), a win-win in such a dangerous environment. Better still, the shelf lives of the food packets go from a year to 18 months (4), providing an excellent margin of error (They are only hypothetical humans after all) for our 6 month minimum flight time. That being said, they aren’t 100% perfect.
Vitamin D, an essential vitamin responsible for calcium and phosphate (Essential stuff for our bones and body reparation) regulation, is a more challenging thing to get into an astronauts system with the lack of sunlight meaning their usual levels may drop, not great when astronauts bone strength is already under threat. Astronauts have to take Vitamin D supplements to ensure their intake remains healthy (5). Another problem that needs to be considered is storage. Though the space meals have excellent shelve lives, the astronauts are going to have to take all their meals on board the Erikson which increases the overall mass that the Erikson will have to (possibly) launch in the space.
Space food does provide an excellent source of food, providing astronauts with a wide variety of easy meals. However, the need for additional supplements does somewhat tarnish their usefulness and the sheer number of packets required will have to be factored in to the overall mass of the Erikson‘s payload.
Whilst freeze-dried cuisine provides astronaut both sufficient energy and variety, it certainly can’t hurt to explore other possible means of sustenance on such an incredibly dangerous journey. Whilst a fully functioning farm is rather difficult to achieve in quite a small space, Plants could be grown to serve as a helpful food source (Plus an incredibly helpful way of cleaning the air).
NASA’s Veggie project, launched in 2014, has allowed astronauts to grow and harvest a number of edible plants on board the International Space Station, the 6 plant beds allowing astronauts to grow a number of leafy greens such as lettuce and cabbage. They have recently attempted growing multiple plants at once, the success of which is still to be determined (7). This allows our astronauts to not only enjoy a fresh salad every once in a while, but also enjoy a bit of variety. With more and more plants being tested, who knows what our astronauts will be able to enjoy during their flight.
But wait one minute, how can plants grow without gravity? Despite the lack of gravity, plants’ roots can still grow into the soil provided its kept nice and moist, the roots will grow in the direction of the water, commonly referred to as hydrotropism (6). The successful growth of plants in space does encourage optimism for future agriculture adventures in the wider universe.
Relying on plant growth does raise a few issues such as water conservation and crop failure but, provided an expert hand is available, plants not only offer astronauts even more variety in their diets but a way of effectively cleaning the on-board atmosphere.
Though far from what these hypothetical heroes deserve, these solutions do offer up a possible way of feeding our astronauts, providing them both enough energy to survive and a bit of variety to boot. There is another “solution” if all else fails but I don’t feel overly comfortable discussing it here. I’ll leave it to your imaginations…
Do you have any suggestions for feeding 6-12 people on-board a spacecraft hurtling towards Mars? Comment below! If you have any other general thoughts or questions, feel free to drop a line in the comments too!
- Wilkinson A. (2017) How many calories should I eat in a day? Available at: http://www.telegraph.co.uk/health-fitness/nutrition/many-calories-should-eat-day/ (Last Accessed: 12th November 2017)
- Pearlman R. (2007) Best Orbital Eats: The Top 10 Space Foods, Available at: https://www.space.com/4664-orbital-eats-top-10-space-foods.html (Last Accessed: 12th November 2017)
- Canright S. (2009) Food for Space Flight, Available at: https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Food_for_Space_Flight.html (Last Accessed: 12th November 2017)
- Raloff J. (2010) Space Food Turns Gross Within a Year, Available at: https://www.wired.com/2010/07/ol-space-food/ (Last Accessed: 15th November 2017)
- Gardiner R. (2014) 13 Unbelievable Things NASA Told Us About Space Food, Available at: http://www.obsev.com/food/13-unbelievable-things-nasa-told-us-about-space-food.html (Last Accessed: 15th November 2017)
- Owen J. (2012) Plants Grow Fine Without Gravity, Available at: https://news.nationalgeographic.com/news/2012/121207-plants-grow-space-station-science/ (Last Accessed: 1st December 2017)
- Herridge L. (2017) How Does Your Space Garden Grow? Available at: https://www.nasa.gov/feature/how-does-your-space-garden-grow (Last Accessed: 1st December 2017)