Fisher Space Pen Refill (with Parker Pen Adapter)
Medium Point - Black Ink
with Parker style adapter
Made in the USA
Fits the Following Space Pen product categories:
- Zero Gravity
- Includes an adapter to fit any Parker retractable pen.
Paul C. Fisher developed the pressurized refill for NASA in 1965. It's still in use today on manned space flights because it performs when other pens fail. The combination of tungsten carbide ball point and thixotropic ink in a hermetically sealed cartridge pressurized at nearly 35 pounds per square inch allows it to write in freezing cold, boiling heat, underwater and at any angle - even upside down!
The cartridges of conventional ball point pens are open to permit ink to be fed to the point. The secret behind the Fisher Space Pen lies in the unique design characteristics of the ink and the high precision manufacturing tolerances of the ball point and socket. The ink is fed to the ball point by gas pressure permitting the pen to write in any position. An additional benefit of the closed design is that it keeps the pen from drying out giving the Fisher Space Pen an estimated 100 year shelf life.