Comments: This is a marvelous story to illustrate the perils of government waste; pity it's not true. NASA didn't have $12 billion to spend on anything when it first started sending astronauts into space in the early 1960s. The agency's entire budget for the 1960 was $500 million; by 1965, it was up to $5.2 billion, still not enough to throw billions away reinventing the ballpoint pen.
Be that as it may, astronauts in the Apollo program did begin using a specially-designed zero-gravity pen in 1968 called the Fisher AG-7 Space Pen. Nitrogen-pressurized, the pen worked in "freezing cold, desert heat, underwater and upside down," as well as the weightlessness of outer space. It was developed not by NASA but by an enterprising individual, Paul C. Fisher, owner of the Fisher Space Pen Company. By his own account, Fisher spent "thousands of hours and millions of dollars" of his own in research and development; not billions.
The Fisher Space Pen is still used by both American and Russian astronauts on every space flight, and you can buy one yourself direct from the company for a measly 50 bucks.