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 body of the pen is all brass with Black Cerakote®, a ceramic polymer-based finish that provides unmatched resilience including scratch, corrosion, heat and chemical resistance. When closed, the Space Pen is the perfect size to carry and when open, it is a full sized, evenly balanced writing instrument. The Space Pen is made in the USA where it is precision assembled and hand tested so it is no surprise that it carries a lifetime promise against all manufacturing defects. It comes in a Moonscape Gift Box with Astronaut Sleeve 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.