Space travel conjures visions of majestic nebulae, distant worlds, and endless vacuum. But what does the final frontier actually smell like? According to astronauts, not quite as romantic.
Foul Odors Permeate the Cosmos
Over the years, space travelers have reported an assortment of distinct scents inside their spacecraft and spacesuits, ranging from the unpleasant to the simply weird.
The lingering odor inside the titanium alloy interior of the International Space Station (ISS) has been described as a combination of “gunpowder, burnt almond cookie, and hot metal,” according to Canadian astronaut Chris Hadfield [1].
Others note hints of rum, raspberries, and even urine. A few claim they smell …nothing at all.
“When you go out into space and come back in you have this smell that permeates your suit,” Hadfield recalled of his first spacewalk in 2001.
So where do these smelly space scents originate?
Source 1: Gases from Faulty Equipment
Some distinctly noxious smells come from the space station itself, according to NASA chemist Penny Roberts [2]. Leaking coolant, worn materials, and astronaut body odor can mix with stale, recirculated air.
“Stowaways also produce smells,” Roberts says. “Samples returned from the space station have off-gassed strange smells that space medicine researchers have described as roasted meat or metal.”
Food spoilage also plays a role. Without gravity, crumbs tend to float everywhere.
“There are areas on the space station where food bits have gotten behind equipment and begun to decompose and that can smell pretty bad,” she adds.
Source 2: Spacesuit Off-Gassing
Spacesuits themselves have a smell, according to astronauts.
The orange ascent and entry suits worn during takeoff and landing are made mostly of synthetics and metal. Like a new car, they give off a distinct “off-gassing” odor from plastics and other freshly manufactured materials.
Spacesuits also build up body odor over time, despite miniature vacuum cleaners that suck away dead skin and sweat.
During spacewalks, however, different smells seem to permeate from outside the station.
Source 3: Burnt Launch Fuel Outside
Some astronauts have reported smelling striking scents while doing “EVAs” (extra-vehicular activities) outside on spacewalks.
“When I opened the [airlock] hatch, I suddenly recognized the smell of something burning,” wrote Russian cosmonaut Maksim Surayev in his online journal after a spacewalk in 2009. “It reminded me of burning metal dust.” [3]
Chris Hadfield concurred in his 2013 memoir:
“On spacewalks there’s one smell: burnt metal, which is the smell running through the airlock after coming in from a long spacewalk,” he wrote.
What causes this aroma unique to spacewalks? According to some experts, it’s likely remnant gases from solid rocket boosters used during launch.
Source 4: Comets and Distant Worlds
Venturing beyond low Earth orbit, astronauts catch faint whiffs of comets and other astronomical objects.
During the 1986 flyby of Halley’s Comet, Soviet probes reportedly detected traces of formaldehyde, hydrogen cyanide, alcohol and several other compounds as they passed through the comet’s tail.
When the Stardust probe sped by Comet Wild 2 in 2004, it captured particle samples later described by scientists as smelling vaguely of rotten eggs and cat urine. The culprit: poisonous ammonia and sulfurous compounds.
Distant planets apparently have smells too, albeit mostly unpleasant ones. Saturn’s giant moon Titan features an atmosphere laced with hydrogen cyanide, said to resemble bitter almonds.
And the upper clouds of Uranus contain hydrogen sulfide, lending a distinct rotten egg scent, according to readings from the Voyager 2 probe [4].
Why Study Space Scents?
Understanding smells helps alert astronauts to problems, making early detection of potentially dangerous leaks and outgassing easier.
Unique chemical signatures also assist stargazers analyze the distant composition of comets and atmospheres of alien worlds.
Granted, some space scents remain a mystery. During a 1969 moonwalk, Apollo 17’s Gene Cernan reported smelling “burnt charcoal” inside his helmet. No source was ever determined.
But after a half-century of manned spaceflights, astronauts have discerned a fairly consistent aromatic tapestry permeating space travel.
Below is a breakdown of the most commonly reported scents inside spacecraft, experienced spacewalkers, and recorded by probes near comets and planets:
| Location | Description of Smells |
|---|---|
| Inside spacecraft | Burnt almond cookie, gunpowder, hot metal, rum, raspberries, urine |
| During spacewalks | Burnt steak, welding fumes, burnt metal, gunpowder |
| Near comets | Formaldehyde, rotten eggs, cat urine |
| Planet atmospheres | Rotten eggs (Uranus), bitter almonds (Titan) |
So while space definitely does not smell like roses, its unique scents help reveal details about equipment functions, gas composition, and the chemical make-up of our solar system.
Just don’t forget to pack nose plugs in your spacesuit.
The Future of Fragrances in Space
While smelly space can cause concern, pleasant aromas might positively impact astronaut health and morale during long-duration missions, researchers say [5].
Imagine the stress of being cooped up for months with a handful of crewmates on the way to Mars. The gag-inducing stench of coolant leaks probably won’t help matters.
Enter synthetic fragrances – in space!
Beyond masking foul odors, researchers suggest improved scents could have therapeutic benefits that boost mood and cognition.
One NASA-funded study allowed participants to sniff essential oils like rose, lemon or eucalyptus before and after completing stressful tasks [6]. Those exposed to pleasant smells showed greater alertness and felt more cheerful.
And in 2017, health tech firm Aromyx patented a scent-dispensing device for space, with replaceable smell cartridges capable of emitting specific aromas on command [7].
So while the aroma of antiseptic spaceships will linger for awhile, astronauts can look forward to more olfactory variety during expeditions of the future.
Maybe even a better smelling crew quarters. And no more nauseating whiffs of coolant with breakfast.
Final Thoughts
While space travel evokes visions of awe and grandeur, the smells permeating the cosmos tell a very different story from postcard pictures of nebulae and galaxies.
But space scents also provide vital health information to astronauts and clues about the composition of our solar system. Scientists can even replicate those smells here on Earth.
So grab some nose plugs, and lets explore space! Just try not to breathe too deeply near Uranus.
To err is human, but AI does it too. Whilst factual data is used in the production of these articles, the content is written entirely by AI. Double check any facts you intend to rely on with another source.
