Does Broccoli Stay Green in Outer Space?

Food fit for a king – even in orbit? Today’s space food is quite comparable with the stuff we eat every day down here on Earth. But even though filet mignon and vanilla ice cream are already on the menu, creating a star-rated restaurant in outer space is a science in its own right, explains Martina Heer, a leading expert on space food.

Dr Heer, is cooking for astronauts the ultimate guest experience?

Well, I can’t think of anything more challenging, that’s for sure. There are two approaches: some nutritionists pack in all the calories and nutrients and hope that it’ll taste okay. The others say that it’s important that the packaging should look appetising as well. We don’t know how and to what extent weightlessness affects our sense of taste and smell. It’s something we hear time and again from astronauts, but we have no scientific data to back up their claims.


Michelin-star chefs Alain Ducasse and Harald Wohlfahrt have created dishes for space travel. When you as an expert on space food join these two celebrity chefs in the kitchen, who has the last word?

I don’t really think it’s my place to tell a three-star chef how to season his dishes. My role is in pointing out to them what the maximum levels of the various nutrients are. In the past, the dishes were often oversalted. Then studies showed that this can lead to changes in the astronauts’ cardiovascular system or eyesight. This is why there are now prescribed limits in place.


A restaurant in orbit – what might that look like, the star-rated restaurant to end all star-rated restaurants?

An interesting thought. But I’m pretty sure the highlight would be the view of Earth rather than the culinary delights. Three out of four astronauts suffer from nausea and vomiting at the start of their mission due to weightlessness. So I think you’d have to spend quite some time on board before you could really enjoy a gourmet dining experience.

For even in outer space, you eat with your eyes first.

Dr. Martina Heer

But in theory you would be able to eat anything?

Almost anything. Most people think of astronaut food as the kind of formula-diet products or liquid food you get at the chemist’s, but that’s not the case. Astronaut food is produced in ways that guarantee it to be completely germ-free – for instance through freeze-drying or sterilisation. We now know that astronauts can eat anything. There are no particular problems with flatulence on board a spaceship, so it’s perfectly possible to consume high-fibre products. What matters most of all, though, is the shelf life – the products have to keep for at least six months. We don’t want to risk having to abort a mission just because a product had gone off. Other than that, there are virtually no limits to the ingredients that can be used, with a few exceptions such as alcohol.


What else did the celebrity chefs find out?

When he was working on his recipes, Alain Ducasse brought in a culinary school to analyse the sterilisation process. The broccoli had turned grey but they wanted it to retain its green colour. So they developed procedures to find out what temperatures should be used for how long to ensure that on the one hand the dish is completely sterile and on the other the colour and structure of the ingredients remain unaltered. For even in outer space, you eat with your eyes first.


The space pioneers from the Apollo missions would no doubt be green with envy if they could see what’s on their successors’ menus…

…well, in actual fact NASA’s Skylab mission at the start of the 1970s had its own fridge on board, so they could spoil themselves with vanilla ice cream and filet mignon. But when the space station was later redesigned and engineers worked out how much energy the fridge used, it was one of the first things to fall victim to budget cuts. Products then had to be developed in such ways that they would keep at room temperature. And things have stayed that way till today.


How much does an astronaut consume in a week?

The number of calories varies according to the individual. We recommend that they consume a certain amount of nutrients a day and this should include 0.8 grams of protein per kilogram of body weight – just as here on Earth. Astronauts have recently been provided with an app to help them monitor their nutrients intake.


And what about even longer journeys, as in a mission to Mars?

That’s still a utopian vision at the moment. The shortest return flight would take 14 to 16 months. It won’t be possible to take all your food supplies with you on board a mission to Mars. So we have to think of ways of producing food on the spaceship, for instance by growing fruit and vegetables in greenhouses. Fish and algae could be a source of protein.


So perhaps we’d better stick to the space station restaurant for the time being?

Maybe. When you think about the number of people who have signed up for flights as space tourists, I’m sure there will be somebody out there who will come up with ideas for special products for these flights.

The expert Martina Heer

Dr. Martina Heer
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Nutritionist Dr Martina Heer has been working on astronaut nutrition for the crew of the International Space Station (ISS) at the European Astronaut Centre (ESA) since 1998. She is one of the leading experts in her field, holds the chair at the International Society for Gravitational Physiology and is a Professor at the Institute for Nutritional Sciences at the University of Bonn.

 

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