"When astronauts return from space walks and remove their helmets, they are welcomed back with a peculiar smell. An odor that is distinct and weird: something, astronauts have described it, like 'seared steak.' And also: 'hot metal.' And also: 'welding fumes.' Our extraterrestrial explorers are remarkably consistent in describing Space Scent in meaty-metallic terms... According to one researcher, the aroma astronauts inhale as they move their mass from space to station is the result of 'high-energy vibrations in particles brought back inside which mix with the air.' "You can read more in The Atlantic HERE.