Why Astronauts Need Good Noses

By Kate Greene | May 3, 2013 10:00 am

This is the fourth in a series of reports from the HI-SEAS simulated Mars mission. Read others in the series here.

Yajaira Sierra-Sastre, crew scientist, administers a nasal patency test to me earlier this year during our two-week practice mission at the Mars Desert Research Station in Utah. Photo by Sian Proctor.

It’s been a little over three weeks since we first stepped into our simulated Mars habitat on the slopes of Mauna Loa. The initial flurry of activity—unpacking equipment, setting up a kitchen and lab,  and inventorying four months of food—has subsided. The six of us on this crew are now in the groove of daily living.

Our Mars days resemble, in many ways, a day on Earth. We cook. We do dishes. Take out the trash. We fix leaky pipes. We work. But we’re also participants in a study to help NASA explore new ways to feed astronauts on a lunar or Martian outpost. As such, we fill out a lot of surveys and are subject to a number of tests. This week, we started inspection of our noses.

The sense of smell and the shape and function of the nose are important to this food study. It’s known that astronauts tend to eat less in space, but the culprit is unclear. Is it because their sense of smell changes as microgravity shifts fluids around in their heads? Or is it because they’re bored with a limited selection of meal options, some of which taste better than others?

Yesterday’s lunch for the HI-SEAS crew: dehydrated turkey, freeze-dried broccoli and potato granules, rehydrated and topped with some instant gravy. Photo by Sian Proctor

The boredom question is being addressed by the design of the HI-SEAS food study. We’re allowed to cook creatively with shelf-stable ingredients for about half the time during this mission. The other half we eat just-add-water meals. We report on our mood, productivity, and general health as well as other measures throughout the day. So if there’s a difference between creative-cooking days and just-add-water days, it will likely show up in the surveys and other metrics.

The fluid-shifting question is being addressed by a set of tests identical to those underway at NASA’s Flight Analog Research Unit in Galveston, TX. At FARU, Bryan Caldwell, a postdoctoral researcher at Cornell, conducts bed-rest studies. This is the sort of research that requires subjects to lie in beds for weeks and months, heads angled down ever-so-slightly to simulate low gravity. In this state, muscles atrophy and fluids shift just as they would in space.

Bryan runs three nose tests on these subjects. The first measures their ability to identify odors. The second examines the flow of air through their nostrils. And the third tracks the potential changes in the shape of subjects’ nasal cavities. These last two tests are looking at the openness of the nose, also known as nasal patency.

The HI-SEAS crew is essentially the control group for that bed-rest study. Like the bed-rest subjects, we’re in isolation with no direct contact with fresh air. Unlike the bed-rest subjects, we get to use gravity. In any case, we must test our noses.

This week we took a scratch-and-sniff exam to get a measure for our ability to accurately identify smells. (We took this same test about a year ago as a baseline.) I don’t want to sound dramatic, but the experience was sublime. I didn’t realize how much I missed certain scents—grass, lilacs, and roses in particular—until this test. It makes me wonder if I’ll start to crave other smells as the mission progresses.

The HI-SEAS habitat on the slopes of Mauna Loa. Photo by Sian Proctor

In a few weeks, we take a different type of odorant identification test in which bits of food and other objects are placed in lidded, opaque plastic cups. The local research team prepares these aromatic treats and delivers them to an outer storage area of the habitat so we never see the deliverers. (In simulation parlance, these cups are “teleported” to our Martian home.)

Using a straw punched through the lid of the cup, we smell the contents and try to identify them as best we can. Out of context and without visual cues, odor identification can be tricky. I’ve been surprised at how hard it is to tell the difference between spaghetti sauce and taco seasoning, for instance.

On Thursday, we completed our first round of nasal patency tests. For these, we plug one nostril at a time with foam and breathe deeply into a mask that measures intake and outflow of air. The other nasal patency test involves a long tube-like object called an acoustic rhinometer that we gently hold to one nostril at a time. Known around here as the nose flute, this instrument sends pulses of sound waves up the nasal passage. The reflected sound is used to map the topography of the inner nose.

I’m pleased to report that, so far, my nose is in good working order. Well, mostly. My left nasal passage seems to have an unusual shape according to measurements by the nasal rhinometer. Nothing to worry about at this point. But it’s likely just one of many potential self discoveries during our four months on Mars.

CATEGORIZED UNDER: Mars on Earth, Top posts
  • http://www.facebook.com/henk.rogers Henk Rogers

    So which comes first pre-made food or team-cooked food? Is it two months then switch, or do you switch more often?

    • http://twitter.com/kgreene Kate Greene of Mars

      Hi Henk,

      We alternate: two days of pre-prepared meals and two days of creative meals.



Field Notes

Firsthand reports from DISCOVER correspondents covering science as it happens.

About Kate Greene

Kate Greene is a San Francisco-based science and technology journalist whose work has appeared in Discover magazine, The Economist, and U.S. News & World Report, among others. She is presently a crewmember of HI-SEAS (Hawaiian space Exploration Analog and Simulation), a 120-day simulated Mars mission, during which she will live on the rocky slopes of the Hawaiian volcano Mauna Loa inside a two-story dome, eating astronaut food. As a kid, she wanted to be an astronaut. Gastronaut’s not bad either. Her Internet home is kategreene.net.


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