Designed by Paul Fisher for the first manned Apollo mission in 1968, the  Space Pen is able to write in zero gravity, under water and over wet surfaces, at any angle including upside down and in extreme temperatures. 

The Cap-O-Matic range utilises cap activation to extend and retract the point, so the pen is ready to go at all times. The body of the pen is all brass with a matte black finish and NASA logo and includes a matching clip. It comes in a Galaxy Giftbox and includes a black, medium ink cartridge, which can be purchased separately . 

The secret behind the unique capabilities of the Space Pen lies in the ink cartridge itself. The  are hermetically sealed, pressurised with nitrogen gas, and feature a tungsten carbide ballpoint tip. This design works perfectly with Fisher ink, which is more of a gel than a liquid, with a consistency similar to that of toothpaste. It is only when pressure is applied to the ballpoint that the ink takes on the spreadable properties of a liquid, while still retaining the stickiness needed to adhere to nearly any material.