Before you go dissing NASA for spending scads of cash on a zero-G pen, allow me to share with you thoughts on this very topic, posted on a different message board, in the context of the Russian's plans to launch the first man-on-Mars:
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One favorite chestnut often bandied about when comparing the Russian space program and the U.S. space program goes something like this:
NASA spent over a million dollars researching how to build a ball-point pen that would write in reliably in zero-g. The Russians used a pencil.
...and this is usually used as a "laugh at NASA/the U.S space program" for being money-burning, over-engineering fools.
The facts as presented are basicly correct. NASA did spend a huge amount of money to develop that pen, and the Russians did simply use a pencil.
The real joke, though, is on the Russians -- for using a pencil!
Of the many problems of living and working in zero-g, one that most people fail to consider is the "housekeeping" problem. Yes, most people know that things float with the air currents in zero-g. Many know that fluids, for example, can become a real mess because they're easily fractured into ever-smaller droplets, each of which will have to be chased down individually. The housekeeping problem that people don't know about, though, is dust.
Sure, dust is a problem for us here on Earth -- we vacuum it, sweep it, brush it away with a feather duster. It's managable, though, because it settles out of the air under the influence of gravity. In freefall, this is another matter entirely. Dust in a spacecraft does not settle, because it's a microgravity environment. It continues to circulate in the air until it gets wedged in somewhere, or sticks to something.
Like the contacts behind a switch.
Like the seals for a hatch.
...and so on and so forth. Dust in contacts can either prevent the switch from closing properly (the thing doesn't work when you press the button) or, under the proper conditions, bridge the gap of an open circuit so current flows when it's not supposed to do so.
Dust on the seals for a hatch can prevent a perfect seal, and can wear away / erode the seal over time and use, making it even less effective.
And these are just two of the myriad problems with dust and grit that will plague a spacecraft over the long haul that don't plague us on Earth...because on Earth, gravity causes dust to settle out of the air.
So...what does this have to do with the Russian pencil? Plenty. I'll get to that. But first, this objection:
"But there's no dust inside a spacecraft! Those things are built in clean rooms! How can dust be a problem."
Quite simply, the above statement is wrong. There is a source of dust inside manned spacecraft -- the personnel themselves. Most (more than 80%) of the dust in the average home comes from the inhabitants, and is composed of microscopic flakes of skin and hair. A spacecraft with a long history of being inhabited will begin to have dust problems just from the dust "shed" by the humans that have been on board.
Now add in a pencil. There are going to be microscopic bits of graphite released as the pencil point abrades itself against the paper. And what about sharpening it? The same problem, only worse.
Yes, in the short run, a pencil is simpler and much cheaper. In the long run, though, going with a simple, expedient, and cheap solution pays some pretty bitter dividends in unnecessary wear and tear on spacecraft systems. The next time you feel tempted to laugh at NASA's "overengineering" or "overspending" by taking the time to develop a ball-point pen for our astronaughts to use, just remember what's at stake.
Taking all the above into account, do you now see why the Russian's "we can do it cheaply" makes me concerned for the lives of the crew? A three-year trip is plenty of time for the "bad" dividends of "cheap solutions" to begin to come home to roost.