Astronauts' fingernails fall off

You know how you always wanted to be an astronaut, because you really wanted to have an EVA jaunt in the great empty of space? Well, good luck with that: it'll make your fingernails fall off. Some astronauts actually pull their own fingernails off before heading into space to get it over with. It turns out that wide-handed astronauts are at the highest risk of "fingernail delamination." NASA's Astronaut Glove Challenge has been running for several years, but still the nails fall off.
In several cases, sustained pressure on the fingertips during EVAs caused intense pain and led to the astronauts' nails detaching from their nailbeds, a condition called fingernail delamination.

While this condition doesn't prevent astronauts from getting their work done, it can become a nuisance if the loose nails gets snagged inside the glove. Also, moisture inside the glove can lead to secondary bacterial or yeast infections in the exposed nailbeds, the study authors say.

If the nail falls off completely, it will eventually grow back, although it might be deformed.

Astronauts' Fingernails Falling Off Due to Glove Design (via JWZ)

(Image: An Old Digit, a Creative Commons Attribution Share-Alike (2.0) image from chefranden's photostream)


  1. Speed skaters deal with the same thing after long races, and it sounds like for pretty much the same reason. Blackened, bruised, and eventually entirely missing toenails are a proud battle scar of both the 87 mile course of Athens to Atlanta and the solo division of 24 Hours Montreal. I’m glad to know we’re in such esteemed company.

  2. Fingernail delamination is the second-most-intense pain I’ve ever experienced (the first was a kidney stone). I can’t imagine pulling my own fingernails off.

  3. “Some astronauts actually pull their own fingernails off before heading into space to get it over with.”

    Good thing space flight doesn’t give you hemorrhoids.

  4. Wow! I am surprised that I have cause to sympathize with astronauts! After reading this, I pulled out the tape measure and measured my metacarpal circumference – turns out it comes in over 9.5 inches.

    I have always had a hard time finding winter gloves. If they come in sizes up to large, I give up right away. There needs to be an extra-large option. Then I have to actually find the one pair out of a hundred that is actually XL. They still must fit evenly, with no pressure points or finger constriction or I’ll get chilled fingers quite quickly. I have a favorite pair of XL insulated winter work gloves that appear enormous when worn.

    bardfinn, I agree completely on the pain of nails! I once screwed up badly and wedged a ¼ inch wide sliver under my nail from the tip all the way to the nailbed. I had about a second of nerve lag to stare at it and think, “d*** that is going to HURT!” Turns out, I was wrong. It was worse than that.

    1. “I have always had a hard time finding winter gloves.”

      Try switching to mittens with silk glove liners inside. Mittens are warmer than gloves in any case, and you can just slip them off and use just the liners if you need a few moments of higher dexterity.

  5. Any runner or hiker I’m sure has had the experience where you worn shoes too small and after a day of being out and about… well, I’ve had my toenails get sorta bloody/red and then after a few days the blood trapped under the nail darkens..

    then it kinda loosens, falls out.. and 3 months later or so it’s all grown back no big deal.

      1. Its the pressure which does it. The gloves have to be extremely tight so the press in on the hands from all directions. In the apollo program many moon walkers regretted not trimming their finger nails before the flight. Most of them got very sore hands. A thimble would still press in on the nail and reinforcing them might make it more likely the nail would come away from the finger.

  6. So… Why not rig up some sort of cable-controlled pseudo-hand (or robotic for that matter).

    I’m imagining elongating the suit arms a bit, with your hand inside the comfort of the arm, placed into an interior glove which transmits hand movements directly to an exterior hand on the end of the sleeve. Should be able to translate the relevant movements with simple cabling, so curling a finger would curl the finger on the suit-end robo-hand….. The tension on the cables should transmit sensation of touch and pressure simply enough….. I know I’m complicating things here (and it gets really complicated if you throw up some telemetry-controlled servo filled hand with remote feedback) but wouldn’t a little extra engineering be better then massive hand fatigue and pressures that literally rip nails off fingertips?

  7. That is so effing gross. I already didn’t want to be an astronaut because of my extreme motion sickness. Not to mention the incredible pain I experience in my ears when I go on an airplane. Add this to the list of physical and psychological discomforts, and how the hell do they find anyone willing to go into space?

    1. Are you kidding? I’d go in a heartbeat. People spend $20 million (if they have it) on a single trip up there. Oh, I end up with ugly nails for the rest of my life? Hey, great conversation starter.

  8. I chew on my nails, so they look just as bad and if not worse than the picture…

    If my whole nail fell off I’m not sure I’d really mind. I don’t have much of a use for them anyway.

  9. I heard they get more gas in space, too. My thumbnail got pussy around the edges and came off when I was in 4th grade, and there was another thumbnail waiting under it.

  10. My kiddie karate master was a psycho South Korean ran-out-of-ammo-Chuck-Norrised-his-way-through-a-Chinese-human-wave Korean war vet. We had to bang our fingers against the wall to toughen them up for like an hour or more during summer training hours. I have never lost a nail even in slammed car doors or weird finger impact and scrape motorcycle accidents where the finger went out of joint. I still get stress nightmares from that guy.

  11. I worked at the NBL (Neutral Buoyancy Lab) in the suit lab a couple of years ago and I saw the effects of delamination first hand, painful.

    Most crew members opt for applying moleskin patches to their finger tips or applying nail hardener, which is pain because you have to wait about tow hours for the off-gassing to complete.

    There needs to be a fix in the design, but I don’t see it happening anytime soon.

  12. They had problems with this during the Apollo moon missions as well. The main issue is you have essentially a rubber glove that is pressurized, making it very hard to squeeze. This makes even lightly gripping something difficult because you have to fight the glove wanting to expand like a balloon.

  13. I’ve lost a couple of thumbnails to car doors, and even had my big toenail ripped out in one swoop. However, I don’t think I could do that ten times as a preventative measure.

    I thought about wrapping one’s fingertips in duct tape before donning the suit, but I guess that’s essentially the same problem…cutting off the blood supply and weakening the nail bed.

  14. I heard about this on NPR yesterday or the day before. Apparently they are working on a new space suit/space glove that can prevent it from happening.

  15. NASA spacesuits have mostly been made by ILC in southern Delaware. ILC is a private, wholly owned company but I’ve visited the plant in the past.

    Originally the suits were entirely custom-made, but now I believe everything but the gloves is assembled out of standard parts; the astronaut is measured extremely precisely, then a suit is pieced together. Using standard feet, forearms etc. means you can ship spare parts to orbit. The gloves were made by wonderful old ladies (and I mean OLD ladies – they must be pushing 100 years old by now) who stitched them by hand.

    Recently – I think within the last five years – NASA started a program to revamp the spacesuits, and specifically the gloves, based on diving suit technologies. Rumor in the space biz was that the primary impetus for the redesign program was the last of the old glovemaker ladies retiring, but I don’t think that was publicly acknowledged.

  16. Incidentally, if you get a fingernail smashed badly enough that it turns red underneath, you should drill a small hole (with a pin vise, not a power drill, don’t be stupid) in the nail immediately to let the blood out. Use a clean sharp drill bit to avoid getting any toxic metals or gunk in the hole.

    If you get the blood out before it turns black, you won’t lose the old nail before the new one is ready, and also it hurts a lot less once you relieve the pressure under the nail.

    I use a 1/16 drill bit, because I still have a big box of them that I got for a dollar when DuPont broke up the Wilmington Shops.

    1. A quicker and easier way to do this is to heat a needle red hot and then just barely touch the point on the nail where the blood is trapped. Quick release, no pain, easier than managing a drill with one hand. :D Obviously you’re holding the needle with a pair of needle(ha!)-nose pliers.

      1. When using this method it is vitally important to follow through until you have drainage. If you pull away too soon you’ll simply boil the fluid under the nail. (Ask me how I know… *shudder*)

  17. Once I got my hands in a undiluted cleaner, three days later all my finger nails popped up like baked peperoni. They all fell off and grew back normally. Hurt a bit for sure.

  18. I need to revise my mental image of the romance of space exploration once again.

    I knew it wasn’t going to be all Han Solo and Buck Rogers, but the revelation that they wear diapers (in case they need to boldly go where no man has gone before) came as something of a shock. Now we learn that our diaper-wearing heroes of the final frontier have no fingernails either. Eww, just, eww.

  19. “The Russians used a pencil.”
    Both the USA and USSR used pencils (which created graphite dust and broken leads that could short circuitry) until a company took the initiative, spent $1 million to develop a pressurized pen, and sold them to NASA for $3 each.
    (Willfully trolled because I really like the story)

  20. I assume by “remove their own fingernails” they mean, “have a doctor in the clinic numb you up and remove them.” I know some long distance runners do this to their feets.

  21. I lost a big toe swimming in a river (I suppose I should say “slipping on rocks in a river in some minor rapids”) in Grand Teton National Park. Didn’t come off right away, but was mostly detached. Had to walk three miles back to the car.

    The thing is though that the water was *freezing cold*. As in, my feet were nearly numb from wading in it – so I didn’t feel any pain :)

    It’s one of my favorite scars (also one of the few largely visible ones) because it’s not just a scar – my toenail naturally grows back with a big dent in it. Something unique to show off when comparing scars.

    1. You really need to put a “nail” somewhere in that first sentence. It was sounding pretty gruesome.

      Regarding the story: seriously, astronauts *rip off their own fingernails* before going into space? I don’t believe it. Getting fingernails crushed and then having them fall off sound a bit painful. Ripping off one’s own fingernails sounds like excruciating nightmarish torture.

      Are other people’s fingernails different from mine? Ripping mine off seems like one of the most painful things I can imagine.

  22. The injuries almost all occur in the NBL (giant pool they train in) due to the sheer amount of time they spend there. The ones who do take off their fingernails do it before the pool, not space.

  23. I smashed my right middle finger in a car’s trunk door, & had a big blood blister under the nail. Since I had started injecting insulin just before then, I took a syringe, stuck it under the nail, & siphoned off the blood. Five days later, the nail was so loose I was able to painlessly pull it out. The nail grew back over the next three months.
    Antinous, I think Mitch meant ‘pus-y’ not ‘pussy.’

  24. This might be stupid, but if it is due to lack of pressure on the nails, why don’t they just tape them?

    Use hockey fabric tape.

    1. The article says new research is making people think the problem’s actually due to pressure on the sides of the finger joints, when we’ve always assumed it was from the fingertips constantly rapping on the thimbles.

  25. With “the Russians used a pencil” comment in mind, have they ever considered taping them before they go out. It might not stop the process entirely, but it would help to slow it, and if it did detach completely it would at least stay in place. This based on personal experience. I broke a toe nail the night before before a 9 day hiking trip, and knew I wouldn’t make if it came off. I taped it on with waterproof medical tape and it was painless and stayed on the whole trip. By the time I got back and took off the tape, the new nail had already started to grow in. We really do need to look for simpler solutions to our problems.

  26. Surely the lesson here is that gloves, no matter how well designed, are not — and cannot be — a good solution to the problem. In hard vacuum, the main desiderata of a glove, ie comfort, flexibility and protection, are just flat out in irreconcilable conflict.

    Instead, why not have a small pressurized sphere at the end of the spacesuit’s arm, inside of which the astronaut’s hand is completely free to move. Also inside the sphere is a set of feedback-enabled control surfaces which operate a robot hand attached to the further end of the spacesuit’s arm.

Comments are closed.