The Smell of Space?

[speedfreek]

"Few people have experienced traveling into space. Even fewer have experienced the smell of space."

These are the words of ISS Science Officer Don Pettit, from an article on the NASA website -
The Smell of Space

I had the pleasure of operating the airlock for two of my crewmates while they went on several space walks. Each time, when I repressed the airlock, opened the hatch and welcomed two tired workers inside, a peculiar odor tickled my olfactory senses. At first I couldn't quite place it. It must have come from the air ducts that re-pressed the compartment. Then I noticed that this smell was on their suit, helmet, gloves, and tools. It was more pronounced on fabrics than on metal or plastic surfaces.

It is hard to describe this smell; it is definitely not the olfactory equivalent to describing the palette sensations of some new food as "tastes like chicken." The best description I can come up with is metallic; a rather pleasant sweet metallic sensation. It reminded me of my college summers where I labored for many hours with an arc welding torch repairing heavy equipment for a small logging outfit. It reminded me of pleasant sweet smelling welding fumes. That is the smell of space.

What do you think it is that he is actually smelling? Would space smell the same everywhere?

[Celeste]

Some suggestions:

If we take the description literally the smell of arc welding is ozone. I donīt know if there would ozone present in the environment, but if the suit had some leakage, even small, maybe the UV light from the sun would turn some normal oxygen molecules (O2) into ozone (O3).

Other possibility is that the outer layer/finish of the suits sublimates when at low pressures and that he was smelling that.

And finally that he was smelling actual small burnings on the suits caused by micrometeorites.

[Gillianren]

Vacuum, by definition, doesn't smell like anything. Smell consists of particles hitting your nasal passages (vast oversimplification alert!); in space, there's nothing to smell--or at least not enough to matter, no pun intended.

[Neverfly]

Vacuum, by definition, doesn't smell like anything. Smell consists of particles hitting your nasal passages (vast oversimplification alert!); in space, there's nothing to smell--or at least not enough to matter, no pun intended.

There are particles in space that could hit your nose if you had access to them.

Once the spacewalkers came into the air and whatever particles that clung to their suits became suspended in the air, it makes sense that one could then smell them.

[01101001]

Of course, the moon (lunar eclipse in progress) smells like... gunpowder.

NASA: Apollo Chronicles: The Mysterious Smell of Moondust

Schmitt says, "All of the Apollo astronauts were used to handling guns." So when they said 'moondust smells like burnt gunpowder,' they knew what they were talking about.

[Gillianren]

There are particles in space that could hit your nose if you had access to them.

Once the spacewalkers came into the air and whatever particles that clung to their suits became suspended in the air, it makes sense that one could then smell them.

Well, yes, there are, but there aren't very many, so the odds that you'd ever have enough of them to reach your nose and be perceived as smell (and the human nose is not at all sensitive) are pretty low.

[Neverfly]

Well, yes, there are, but there aren't very many, so the odds that you'd ever have enough of them to reach your nose and be perceived as smell (and the human nose is not at all sensitive) are pretty low.

true. Most likely there was something else clinging to the suits causing the smell.

[astromark]

I would look for some other source of the smell... like the air scrubbers and pumps or the cleaners used to prepare those space suits and the reaction to a re-pressuring atmosphere. The air lock. We are all aware of the smell of an air conditioning unit. A hot motor could reproduce a welding smell. I trust the tech., boys will be researching this smell any time soon.

[Neverfly]

I would look for some other source of the smell... like the air scrubbers and pumps or the cleaners used to prepare those space suits and the reaction to a re-pressuring atmosphere. The air lock. We are all aware of the smell of an air conditioning unit. A hot motor could reproduce a welding smell. I trust the tech., boys will be researching this smell any time soon.

Also, ask around with other astronauts and other mission astronauts and see if others noticed it too.

[BigDon]

It would seem to me that space travel is going to smell like people confined in a small place with no windows and inadequate bathing facilities. In the Navy we called that Foot and *Donkey* smell.

Since humans without large pools of water stink abominably, actual space travel is very likely to smell like bad feet and flatulence.

[Ara Pacis]

He was probably smelling micro-singed spacesuit.

[Larry Jacks]

Perhaps it's the smell caused by the reaction of atomic oxygen (present in LEO) with the space suit materials. Atomic oxygen reacts with many materials used in space. While the concentration of atomic oxygen is space is low, some of those space walks are lasting over 6 hours. A space suit sweeps a considerable volume of space in that time so it could encounter quite a few of those oxygen atoms. Perhaps the smell is the result of an oxidation process or perhaps atomic oxygen itself has a smell.

[mugaliens]

...and the human nose is not at all sensitive...

While not very sensitive compared to the olfactory systems of many animals, the human nose remains extremely sensitive to certain chemicals, capable of picking out just a few molecules of some chemicals among the many billions passing by.

[Tucson_Tim]

I recall an astronaut stating that space smelled like the East River.

[AndreasJ]

People who were at or near Chernobyl in the immediate aftermath of the disaster described the air as tasting metallic. I can't help but wonder if there is a common factor here in the form of (terrestrially) unusual radicals produced by irradiation, or something like that.

[Gillianren]

While not very sensitive compared to the olfactory systems of many animals, the human nose remains extremely sensitive to certain chemicals, capable of picking out just a few molecules of some chemicals among the many billions passing by.

Also true. However, I think the odds of the particles in the mostly-vacuum of space being those particular chemicals are also pretty low.

[Occam]

One of Buzz Aldrin's anecdotes describes the smell of the Moon. Upon their return to the Lunar Module, there was naturally a great deal of lunar dust on their suits. He described the smell as being very much like that of gunpowder.

[mugaliens]

Kevin Ford (as well as other astronauts) have reported that space smells. Digging into the artical, however, it's not space itself that smells, but the spacesuits after they return from a spacewalk. They describe it as "something akin to gunpowder or ozone."

I'm surprised they're surprised, and surmise it must be something as simple as exposure of the synethetic out layers of the suit to solar wind, ionizing radiation, and micrometeorites.

What is, it, exactly?

[nauthiz]

In one of the linked articles an astronaut suggests that it could be from atomic oxygen that clings to the spacesuit fabric. So maybe that ozone smell is just ozone.

[John Jaksich]

I have heard the stories of "space" smelling like Ozone.

Here is a NASA link of Astronaut Don Pettit describing his experience:

http:///spaceflight.nasa.gov/station...ronicles4.html

[01101001]

See topic The Smell of Space?.

[Swift]

Threads merged

[rommel543]

I have two hypothesis on this. One is that when they open and close the air hatch, a small amounts of air is going to be still in there. When that air is exposed to the solar radiation in space it's forming Ozone. The other is that the EVAs from the IIS and shuttles are still within a very close proximity to Earth. It could be the natural burning off of our atmosphere that they are coming in contact with. Like being in a welding shop, that gas is going to be coming in contact with you even if you're not doing the welding, the astronauts are floating through the gases as they are burned off from solar radiation.

I wonder if the smell is stronger on the dark side than the light side or visa versa.

[Drbuzz0]

I don't remember where I read it, but there was a description I saw of one of the Russian Space Stations (I believe pre-mir) that described the small as something like a combination of "Bland canned meat, body oder and a chemical toilet"

[centsworth_II]

And then there's this...

The first space blogger, Anousheh Ansari informs us that space smells like a 'burnt almond cookie'