Space, the final frontier of smells!

January 28, 2004 7:26 PM

The smell of space. How and why? [much more... out there.]

In this thread on the demise of Columbia, mrmcsurly pointed to a William Langwiesche article which said "The smell inside the shuttle is distinctly metallic, unless someone has just come in from a spacewalk, after which the quarters are permeated for a while with 'the smell of space,' a pungent burned odor that some compare to that of seared meat, and that Bloomfield describes as closer to the smell of a torch on steel." I've been haunted by that idea since reading about it.

Some googling has revealed many descriptions, few explanations, and no clear consensus: We call it "the smell of space." But to me it's like an ozone smell — if you ever smelled ozone as a result of a [electric] shock or static electricity or whatever. I think it's probably a result of the atomic oxygen that's prevalent at that altitude. We don't have much of an atmosphere up there — a few molecules floating around — and I think that what we smell when objects come back in. It happens whether it be a spacecraft that's just docked and you open that hatch, or someone who's been on an EVA for a while and brings the suit back inside.

"It still reminds me of sweet welding fumes," he said. "And it may not actually be the smell of space. It may be off-gassing from the space station structure. But I take enough poetic license to label it as the smell of space."

Actually anytime there's metal that's exposed to space, it takes on kind of a unique [smell]. I would call it an ozone smell.

It was as if someone was welding down the corridor. You know why? The airlock metal's oxide coating had evaporated into space, leaving this really fresh layer of metal."

At the risk of killing the romance... what would various sorts of space 'smell' like, once brought inside, and why? what are shuttle/Mir/ISS astronauts really smelling?

posted by stonerose to health & fitness (11 comments total)

maybe it's the leftover burnt/heated smell from escaping the atmosphere?
posted by amberglow at 8:14 PM on January 28, 2004

I've read that the Apollo astronauts smelled something from moondust:

When the astronauts took off their helmets inside the LM after their moonwalk, they noticed a strong odor. Neil described it as “wet ashes in a fireplace” and Buzz as “spent gunpowder”. It was the smell of moondust. NASA, by the way, had been worried that moondust might explode on contact with oxygen.

It smelled like gunpowder. That smell went away but after the first EVA we got these loose bags of rock and the dust we tracked in, we took our helmets off, and [sniff] the initial smell, was a smell like gunpowder a little bit. But then you lost it, it all sort of faded away.

Very romantic stuff, space smells.
posted by interrobang at 9:32 PM on January 28, 2004

Aren't things burning up in our atmosphere basically all the time? There are shooting starts every night, not just on meteor shower night, and though most of them are small, sand-grain-small, I'm sure they smell, collectively, like ozone.

I would like to note, however, that there is no evolutionary reason why we would be able to make subtle olfactory distinctions between the various substances in space. There's probably a world of variation that we're just not tuned in to. For all we know, aliens could land on any part of the earth and smell nothing but the overpowering stench of oxygen and nothing more.

btw stonerose, if you want to smell that "ozone" smell that people sometimes talk about, but which can be difficult to put your finger on, come out to Burning Man and see Dr. Megavolt. His 6-foor Tesla Coil and the electrical arcs it fires off fill the air with it. Unmistakeable.
posted by scarabic at 10:28 PM on January 28, 2004

Smell Mars. Smelling stuff going into space. Ripe orbiter. Smelly node. Musty airlock.

I'm surprised not to find anything indicating a NASA study of the smell, given the attention given to stuff going up. In actuality, the smell is probably largely Orbital Maneuvering System propellant -- a combination of hydrazine "rocket fuel" and a nitrogen-based oxidizer, which can burn in the complete absence of environmental oxygen. During orbit quite a bit of this burnt fuel probably hangs around in the general shuttle vicinity, bodies in motion &c. (There is concern about such gasses around ISS, which rarely changes its orbital position.) In theory, a pure reaction's by-products are the everyday N, CO₂, and H₂O; but then, Nitrogen was once called Burnt Air.

The smell inside new modules of the ISS is probably a really intense variant of new-car, new-office smell -- lots of off-gassing plastics and such. Later, you have such mundanities as body odor to contend with, although it's said the air scrubbers do a tolerable job of handling it. On Mir, they never had enough Progress cargo vehicles to take away the garbage (which would be bagged and stuffed inside, eventually to burn up with the vehicle on re-entry), but the ISS has had the shuttle to carry up plenty of fresh water (to keep clean! and yes, it's recycled -- through a distillery) and carry garbage back. There's no budget on any space mission for laundry, though, and so either your clothes come back with you, or you run through a supply, changing just frequently enough. And all space vehicles, despite common misconceptions (It is very cold in space, Kirk!), are overly warm and inspire light clothing choices.
posted by dhartung at 12:10 AM on January 29, 2004 [1 favorite]

space means never having to blame the dog.
posted by quonsar at 1:28 AM on January 29, 2004

It's the smell of the singed moonbeams.
posted by Pericles at 3:30 AM on January 29, 2004

There's a couple of possibilities I can think of, but they all basically amount to having highly reactive stuff out there--and in any case I think it's not space itself that's being smelled, but the product of the space suit (or anything else exposed to space) reacting with these.

First, you have individual atoms. We don't have many atoms floating around free of molecular bonds down here on the ground. As stonerose's link points out, there is that up in space--noticably atomic oxygen, but other elements in atomic form as well. Most elements are highly reactive in atomic form, and the product of them reacting with things like a space suit probably result in unusual molecules being produced, which could account for the smell.

Second, you have cosmic rays. These are highly energetic photons, powerful enough to knock electrons out of molecules (the sort in a space suit, or whatever other equipment you're using externally). We get a few of these down here on the ground, but the atmosphere shields us from most of them. Knock an electron out of a molecule, and you likely end up breaking it up, at least partly, and the fragments could be highly reactive, breaking up other molecules, so you get strange unfamiliar smells.

A third possibilty is the charged particles (particularly electrons) in the solar wind. Now, the shuttle is in low earth orbit, and should still be mostly protected from these by earth's magnetic field, and I'm not sure how much gets through so I don't know if that would be a significant source. But same deal: pump an extra electron into a molecule, you may well break it up, highly reactive fragments yada yada yada.

Note: ozone is also highly reactive and likely has similar effects.
posted by DevilsAdvocate at 5:25 AM on January 29, 2004

Langewiesche sort of responds to this question in the Letters to the Editor section of the latest Atlantic Monthly (January/February 2004):

"The 'smell of space' exists. It has an acrid or burned quality. But neither I nor the astronauts I've asked yet understand its origin" (p. 18).

posted by arco at 9:12 AM on January 29, 2004

Very cool. Thanks for the answers, everyone. Especially Pericles, who did his level best to keep the romance alive. ;-)
posted by stonerose at 9:52 AM on January 29, 2004

limburger!

posted by jpoulos at 12:41 PM on January 29, 2004

It might very well be the smell of oxidation. When you chuck rocks down a cliff, often there's a smell of... well, rock. It's different than just ordinary rocks; it's the smell of rocks that have tumbled -- chipped and split open, rock exposed to the air for the first time.
posted by five fresh fish at 12:41 PM on January 29, 2004