The proton is one of the basic units of an atom. For the purposes of Space development, a proton is the same as a hydrogen atom and is the main component of solar wind. It can be considered an H1+ ion. Ionized protons can cause you quite a bit of trouble as they can penetrate fairly deep and are often accelerated to very high speeds. These high speed protons are sometimes referred to as cosmic rays.
Protons have a positive charge of 1, and in chemistry a relative mass of 1. The actual mass of a proton is approximately 1.007,276,466,88amu (atomic mass units). When bound in an atom of a relative mass greater than 1, some of this mass will appear to be lost but exists in the form of binding energy (sometimes referred to as nuclear force or residual strong force) which holds nucleons together.