Fisher Space Pen because it doesn't rely on gravity to make it work, thus enabling it to write underwater or upside down.
Pen Add-on Fisher Space Pen bullet, Black and Brass
Fisher Space Pen Bullet Ballpoint Pen - Medium Point - Chrome
Space Pens, Pencils, and How NASA Takes Notes in Space - Tech Briefs
The Astronomical Promises Of The Fisher Space Pen
Matte Black Cap-O-Matic Space Pen - Fisher Space Pen
NYPL Vintage Stamp Brass Space Pen
Fisher Space Pen Bullet - .375 Cartridge Pen with Clip
FIELD NOTES Space Pen Ballpoint (Final Frontier) – WRITER
Fisher Space Pen Bullet Ballpoint Pens - Bullet Space Pens
Fisher Space Pen - 400PP Purple Haze Bullet Space Pen - Ballpoint
Fisher Space Pen From the Pen Cup
New York Public Library Chrome Fisher Space Pen
