You're probably thinking "it's just carbon, nbd", but that doesn't mean it's good for your lungs:

https://www.inchem.org/documents/icsc/icsc/eics0893.htm

"Repeated or prolonged inhalation of dusts may cause effects on the lungs. This may result in graphite pneumoconiosis"

What do you mean? Graphite can be fine or sharp, you saying it's fine to breathe in? I know I wouldn't want to breath in a broken tip of a pencil.

Have you broken a pencil tip? I wouldn't want to breath that in after it goes flying.

Except this wasn't a cost plus contract, this was NASA buying a thing at discount on the open market. In fact, the USSR paid the same discounted bulk price per pen that NASA did.

Your points about a cost-plus contract have merit but aren’t applicable here because the pens weren’t developed under a contract at all. Paul Fisher of the Fisher Pen Company had started developing a pressurized pen before the space program even began (to develop a pen that could write in other orientations than on a desk), although learning of the concerns from the program gave him renewed impetus to solve the design. Fisher patented the design in 1966 after ten years of development and about $1 million in cost. Prior to the pens NASA had been purchasing special pencils at $128.89/each. The original purchase order for the pens bought 400 at $2.95/each.

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The Soviet space program bought the pens in 1969, and besides the Americans they’re still used today by the Russian and Chinese space programs. You can buy one yourself for as little as $7 if you don’t care about it being refillable. On the one hand that’s a lot for a disposable pen, on the other hand that’s not terribly expensive for a pen that writes upside-down if you need that, and might not feel too bad if you’re prone to losing pens.

To add onto the other comment:
NASA wouldn't have to pay anything if the research didn't work out and maybe even avoided other companies who then weren't compensated for their efforts.

They’re referring to the relationship between surface area and combustion. Talc, for example, melts but does not burn. Talc powder can ignite if blown over an open flame.

In technical safety terms, combustibles are harder to ignite than flammables. So diesel and olive oil are combustibles, for example, because neither of them give off enough ignitable vapour at room temperature. Ethanol does, so it gets classified as flammable, and you need to store and handle it more carefully than diesel. Then there's really horrible stuff like triethylborane which will catch fire upon meeting oxygen even at temperatures well below the freezing point of water

Of course in casual usage they mean the same thing

You're not dense for asking a question. Without asking questions, it's Impossible to learn.

The flash point is different. The flash point is the temperature that is necessary to create enough vapor for the substance to ignite.

Flammable material has a low flash point, which means it catches on fire easily. Think gasoline. Combustibles need a higher initial temperature, but eventually they will burn and sustain the burning until running out. Think wood.

You misgendered round spicy flames

I don’t know where you got any of this, your comment makes the least sense of anyone in this post, and some of these people are actually wrong

Wood is also combustible. You need a lot of heat to make wood burn. Hold a lighter to your pencil, it will not instantly catch fire, do the same with paper and you need a water bucket nearby.

And Paul Fisher really just wanted to make a cool pen that can reliably write upside down. Congress and The Party agreed that the pen was cool and bought a couple hundred each.