There was an ongoing discussion on how fisher pen was invented independently for safer writing method.

I was just wondering weather we can use chalk and blackboard in space?

Also if there are challenges in making regular use of it, what are the solutions to the challenges.

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    $\begingroup$ I don't have a source to write a proper answer, but yes you could. No gravity is needed, just friction. As long as you have the leverage to press the chalk against the board, you will rub chalk onto the board. The biggest issue is that chalk notoriously produces dust, which will not settle and becomes a breathing hazard. $\endgroup$
    – DrSheldon
    Commented Sep 6, 2021 at 7:35
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    $\begingroup$ I would expect chaulk to work even if you didn't have an atmosphere. $\endgroup$ Commented Sep 6, 2021 at 16:27
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    $\begingroup$ I wondered why they would need a special "space pen" when they could simply use instruments like pencils, grease pencils, and felt-tipped markers (erasable and permanent). Turns out, they did. You could get all the functionality of chalk, with (close to) none of the drawbacks. $\endgroup$
    – frIT
    Commented Sep 8, 2021 at 8:00
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    $\begingroup$ @DrSheldon: I'm curious about the chalk dust - wouldn't proper air circulation and filtration deal with that? $\endgroup$
    – Vikki
    Commented Sep 9, 2021 at 1:21
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    $\begingroup$ @Vikki: That's an excellent question which has not been directly asked or directly answered on this site. Why don't you submit it as a proper question? $\endgroup$
    – DrSheldon
    Commented Sep 9, 2021 at 3:20

3 Answers 3


There's no scientific reason against using a chalkboard, zero gravity isn't an impediment as making a mark is dependent on pressure between the chalk and the board. The reasons for not using chalk are all practical:

  • Chalk boards are bulky and heavy
  • Chalk marks are not fine, you have to write large which is impractical in cramped conditions
  • Getting enough pressure on the board may be tricky in zero gravity
  • Chalk creates dust, this is a problem for a number of reasons
    • Chalk dust will get sucked into the fans that cool computers and other machinery, possibly causing component failure in the future
    • Chalk dust will clog air filters, or at least reduce their useful life
    • Most of all, chalk creates dust which is a throat and eye irritant
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    $\begingroup$ The dust issue is also why most places I know have already eliminated or are in the process of phasing out chalk boards in favor of white boards and dry erase markers even down here on Earth. $\endgroup$ Commented Sep 7, 2021 at 15:40
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    $\begingroup$ Also: erasing chalk requires considerable amount of water. $\endgroup$ Commented Sep 8, 2021 at 8:30
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    $\begingroup$ The reason dust is a problem in space but not in a classroom is because in a classroom dust falls down into the tray under the chalkboard and stays there. In space there is no down. $\endgroup$ Commented Sep 8, 2021 at 21:03
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    $\begingroup$ That's true to a point @candied_orange, on earth fine dust stays in the air and irritates eyes and noses, that's why blackboards have been phased out. $\endgroup$
    – GdD
    Commented Sep 9, 2021 at 7:40
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    $\begingroup$ @candied_orange There's also the noise issue. "Nails on a chalkboard" is synonymous with painful sound for a reason. $\endgroup$ Commented Sep 9, 2021 at 20:10

@GdD's answer is complete, but I'll elaborate on the chalk dust.

They pretty much can't even have bread or cake on the ISS due to the crumb production; a manual chalk-dust generator would be a nightmare in comparison.

And the work involved in going outside to banging the erasers together to clean them is more trouble than it's worth. I predict that if there were chalk boards and erasers on the ISS they'd just put the dirty erasers in the trash like they do towels and used clothes, and get new ones each time.

lower volume first:

crust-encapsulated, bite-sized "space breadlet" one can pop in one's mouth to avoid making crumbs, from https://space.stackexchange.com/a/42071

space breadlet

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    $\begingroup$ Banging the erasers wouldn't be that big a problem--build something that can do it outside. The rest of it, though--nobody's flying chalk! $\endgroup$ Commented Sep 7, 2021 at 3:18
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    $\begingroup$ @Loren Good point! Gee, the automatic orbital eraser-banger and associated feedthrough port sounds like a great phase II SBIR contract $\endgroup$
    – uhoh
    Commented Sep 7, 2021 at 3:50
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    $\begingroup$ @Michael - of course they would. And then, they'd need cleaning out or replacing far more often. $\endgroup$
    – Tim
    Commented Sep 7, 2021 at 7:31
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    $\begingroup$ @SethR But the drag-to-mass ratio of chalk dust will be very different than that of the ISS, so it would not just 'hang around' $\endgroup$
    – Mr47
    Commented Sep 7, 2021 at 14:56
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    $\begingroup$ There's the risk of potato chips. $\endgroup$ Commented Sep 7, 2021 at 16:15

What hasn't been mentioned yet is the problem Fisher solved with the "Space Pen": Normal ball point pens need gravity to pull the ink down towards the ball at the bottom; they would not write for extended periods of time against or even without gravity. According to the Wikipedia page ball point pens were popularized in the U.S. only in the 1950s by Marcel Bich through the now ubiquitous Bic brand. They were as much bleeding (or hopefully not bleeding!) edge technology as space travel itself. The "Space Pen" had a pump mechanism which could pressurize the ink reservoir, thus forcing the ink towards the ball.

Of course, chalk is not subject to the complications of fluid dynamics under zero gravity ; there is no flow of substance but just abrasion, which works under about all conditions which does not melt, evaporate or otherwise compromise the two surfaces involved.

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    $\begingroup$ I seem to recall there was a test of this, and regular old cheap ballpoints worked perfectly fine in zero G, as they operate mainly by capillary action rather than gravity. You can test this on Earth by using a regular pen while writing on paper against the ceiling (or some other surface above you). The actual problem solved by the space pen is one of ink leakage under pressure/temperature differentials and outgassing of the ink. (Also most astronauts were perfectly happy using pencils before that - often grease pencils designed to not create dust or shavings.) $\endgroup$ Commented Sep 9, 2021 at 14:21
  • $\begingroup$ @DarrelHoffman I believe you're correct on that regular ballpoints work fine in zero G, but trying to write on the ceiling in one G will quickly show that capillary action in ballpoints is insufficient to overpower Earth's surface gravity. $\endgroup$
    – 8bittree
    Commented Sep 13, 2021 at 20:02
  • $\begingroup$ @8bittree A better test might be to use the wall? With the pen perfectly horizontal, the effect of gravity on the ink should be basically nil. I do remember seeing someone do the ceiling test on YouTube somewhere, and it seemed to mostly work, but it might depend on the pen. $\endgroup$ Commented Sep 13, 2021 at 20:18

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