Astronauts returning from spacewalks often report a distinctive odor clinging to suits and equipment, commonly compared to grilled meat, hot metal or welding fumes
Astronaut reports and common descriptions
Many spacewalkers describe a lingering scent on their suits and gloves when they re‑enter the airlock, likening it to seared or burnt steak, gunpowder or hot metal, a sensory detail repeatedly mentioned in firsthand accounts and reporting.
Why there is a smell
The vacuum of space itself cannot carry odours, but molecules and reactive species at the space–materials interface produce volatile compounds when space‑exposed surfaces interact with atomic oxygen, ultraviolet radiation and high‑energy particles. These reaction products adhere to equipment and release a strong aroma once they encounter cabin air.
Variation in perception and reported similarities
Descriptions vary between astronauts, but the common comparisons—burnt meat, welding fumes, ozone or gunpowder—reflect a mix of metallic, charred and oxidised organic notes that depend on suit materials, the exact chemistry involved and individual smell perception.
What the phenomenon reveals
The experience highlights how extreme space conditions produce unfamiliar chemistry and how encountering those reaction products in spacecraft atmosphere translates into vivid terrestrial smell analogies, giving a sensory glimpse into otherwise invisible processes outside Earth.
Takeaway
Although space has no air to carry scent, astronauts consistently report a strong, distinct aroma on gear after extravehicular activity caused by space‑induced chemical reactions on surfaces, often described as burnt steak, welding fumes or gunpowder.