Most of us have not heard of the Space Pen. But if you have, it probably was by hearing/reading that NASA spent billions of dollars to develop a special ballpoint pen that would work in space, but the canny Russians simply used a pencil.
Well, yes, the Space Pen does exist, but in reality, when they say billions of dollars, they mean $2.39.
Space travel is dangerous. A spacecraft, like a submarine running underwater, is a closed environment – but with extra hazards.
In space, the lack of effective gravity means that everything just stays where you left it.
A warm gas (like the air you breathe out) doesn’t quickly spread out in all directions. Solid stuff doesn’t automatically drop to the floor. With a pencil, if the tip of the graphite point breaks off, it just floats in the air. If you sharpened a pencil, so would the wood shavings or graphite dust.
This floating debris could land in your lungs, or your eyes. But it can get worse. If the debris conducts electricity (like graphite does), it’s a major threat to electronic components and electric switches. Graphite is also inflammable.
The Russian had problems with pencils. The cosmonaut, Anatoly Solovyev said, “pencil lead breaks … and is not good in space capsule: very dangerous to have metal lead particles in zero gravity”.
In 1965, Paul C. Fisher from the Fisher pen company in California independently (ie, nothing to do with NASA) developed and patented the AG-7 pen. (AG meant Anti Gravity.)
It looked like a regular ball-point pen.
But the first difference was that the ink was a thixotropic gel – pressure would turn it from a semi-solid gel to a liquid. Second, the ink was pressurised at two atmospheres (similar to the pressure in your car tyres) by compressed nitrogen gas, to continuously force it up against the ball in the tip of the pen.
When you started writing, the tungsten carbide ball rolling across the paper rubbed up against the gelatinous ink, and sheared the chemical polymer bonds in the gel. The gel turned into a liquid, coated the rolling ball and was promptly deposited onto the paper.
Gravity has no role in this scenario – the pen would work in the microgravity of space.
The total cost of developing this technology was claimed to be around $1 million. It was NOT paid for by NASA. The cost was carried entirely by the Fisher Pen Company – a private company. (That’s completely different from NASA spending billions of dollars.)
By 1967, NASA had ordered 400 Fisher space pens for their Apollo program.
The Russians followed suit, and ordered 100 pens and 1,000 ink cartridges to use on their Soyuz space missions. In other words, as soon as the Russians could stop using pencils, they did.
And because both NASA and the Soviet space agency were buying in bulk – they apparently each got the same 40% discount. Instead of paying $3.98, they paid $2.39.
But when was the truth ever enough get in the way of a good story?