Ever wondered what astronauts might be eating for Christmas dinner? I found out recently when I had the chance to speak with NASA's Vickie Kloeris, who manages the food system for the International Space Station.
Q: What goes into managing the space station's food system?
A: We have a food lab here on site (Johnson Space Center, in Houston) that serves as the primary provisioning lab for all the space station food. We do a lot of freeze drying here. We also have a facility up at Texas A&M that processes canned foods—not metal cans but pouches, flexible cans. The military developed the "retort pouch" many years ago to replace metal cans because it is lighter in weight and more efficient to stow.
Q: Do you take requests from the astronauts? For holidays, or just in general?
A: We can. For every month that the crewmember is in orbit they get what’s called a bonus container and they can make special requests, if they have a special candy or cracker or cookie they want to take. But our standard menu includes a lot of traditional holiday foods. Smoked turkey, candied yams, green beans, freeze dried cornbread dressing. The Russian side has really good mashed potatoes, and cranberry sauce. So there are foods available for them to make a holiday menu, and if they know they’re going to be in orbit at Christmas time they can take related things in a bonus box. And there might be a crew care package from families, too. Things like a certain kind of nut or hard candy that are part of their tradition on the ground.
Q: Here's a question from a reader: Do astronauts still drink a lot of Tang?
A: We still have several flavors of Tang in the menu, some that you can’t purchase in the U.S. like mango or pineapple. The orange we typically have here; grape we often have. Cookies, crackers, nuts, those kinds of things we use off the shelf and repackage.
Q: How do you decide what kind of cookies to buy, for example?
A: This program has developed over 30 years. During Apollo and Mercury and Gemini, they had a highly customized food system and discovered that that cost a boatload of money. So going into the shuttle program, they determined that they would use as many commercial products as they could. When I came in 1985 they were using mostly commercial items and MREs. Over the years we’ve added stuff in. And then when we knew our crew members were going to be in orbit for months at a time, we knew we needed to have more variety, more thermostabilized products, and we started developing more products.
When we look at a commercial cookie we’ll look at shelf life, how many crumbs it’s going to make—typically we want something bite-sized. A big cookie or cracker would create an awful lot of crumbs. There’s a certain amount of crumbing that occurs anyway. It’s a real nuisance in orbit.
Q: Is there anything they can't have, even on Christmas?
A: Well, they can’t have anything that requires refrigeration. There's no way to refrigerate on the trip up and then on station there’s no dedicated refrigerators for food, although they do have a small chiller now for beverages, to cool after preparing. They only have warm water and hot water, otherwise.
Q: Could they have soda?
A: Carbonated beverages, no, the only way you can have that in microgravity is in a pressurized container because the carbonation would not stay distributed. So you're talking about a $2,000 can of soda.
Q: What about caffeine or alcohol?
A: There’s an awful lot of caffeine consumed on station. We’ve got a lot of heavy duty coffee drinkers! Alcohol? No. We don’t do alcohol. It’s considered by NASA to be a huge safety hazard.
Q: Nutritionally, do they need different things?
A: NASA has been studying nutrition in space for a long time. Overall there doesn’t seem to be a whole lot of difference, but there are a few things—for example you don’t need as much iron in microgravity because you’re not turning over red blood cells as fast. There’s a few things like that, slight differences.
Salt is an issue. I mean, people on the ground eat too much salt–the typical American diet is somewhere between 5 and 10 milligrams a day, way above the RDA. And for astronauts one of the problems too much salt can be cause in microgravity is bone loss. They have bone loss anyway in microgravity. So we try to limit sodium.
Q: Do they really eat that freeze-dried ice cream sold in science gift shops as "astronaut ice cream"?
A: No, we don’t fly that, because they don't ask for it. Kids like it but it doesn’t really appeal to adults. It’s more like hard cotton candy than real ice cream.
A: We don’t get any requests for that but it has a very long shelf life, so yes, I guess we could do that.
Q: Do tastes differ in space?
A: We have a lot of anecdotal evidence from astronauts that their tastebuds are affected in microgravity. It’s very probably related to the fact that when they’re in microgravity their ability to smell the food is compromised. Think about when you’re on the ground and you have a cold and your nose is stopped up---the food tastes different.
When they first go into orbit the fluid shift makes them very congested and that interferes with smell.
They’re also in a confined environment, so any competing odors are going to interfere with their ability to smell the food. Plus they’re eating out of packages, and convection doesn’t work the same, so smells don't rise up. So it makes sense that they perceive that their tastebuds are somewhat dulled. So they go for salt, sauces and hot sauce. They use a lot of condiments.
Q: I imagine it's hard for astronauts to be away from family on the holidays. Is there any upside to spending holidays in space?
A: The great thing about being on station is you can celebrate Christmas twice because the Russians celebrate orthodox Christmas in January. They get the day off so typically they will plan a special meal, pull out some of the special foods. In talking to some crew members, they say the socializing around the meal is a big part of holiday, just like on the ground.