alpha - angle between the incident light and the ship's reference axis or the normal to a flat reflector
areal density - the mass divided by the sail area, expressed in g/m2, typically using sail mass, sail+bus mass, sail+bus+payload mass, or membrane mass before fabrication into a sail
boom - a linear structural element that holds a sail(s) open, typically extending from a ship's center or from a mast
characteristic acceleration - the acceleration a sailing ship would experience at 1 AU from the Sun while facing the Sun, used as a reference of performance, abbreviated as ac
disk sailer - a ship with a circular plan form, often without compression members and relying on stiffening by means of rotation
Doppler effect - a shift in wavelength caused by relative motion of a body toward or away from the source of the radiation or sound
Earth synchronous - Sun-centered orbital motion where a sail or other craft maintains a constant position relative to Earth
gravity assist - an encounter at hyperbolic speed with a body of substantial mass which results in turning the velocity vector of the spacecraft, typically used to change orbit energy, size, eccentricity, inclination, or orientation
heliogyro - a rotating sailer using long blades for sails; the blades twist to control the ship
light pressure - pressure on a surface obtained by changing the momentum of impinging light (or other electromagnetic radiation)
light sailing - travel in space using light pressure for propulsion of a sailing ship
mast - a linear structural element perpendicular to the plane of the sails
planet synchronous - Sun-centered orbital motion where a sail or other craft maintains a constant position relative to a planet
rigging - the set of lines giving strength and stability to a system of sails, booms, and mast(s) (if included)
sail - a thin, often large, often membranous structure used for propulsion or attitude control of a ship, spacecraft, or other space structure
sail loading - see areal density
sailer - a sailing ship; a ship using sails
sailor - a crew member on a sailing ship; a person working on space sailing ships who would, with no hesitation, sign on as a crew member if an opportunity was available
solar pressure - light pressure obtained by using unaltered light from the Sun or other star
solar sailing - travel in space using solar pressure for propulsion of a sailing ship
solar wind - the flux of particles emitted by a star, mostly electrons and protons traveling at a few hundred meters/second at 1 AU, carrying less momentum than sunlight
space sailing - travel in space by means of pressure on sails
sphere of influence - the roughly spherical volume of space centered on a planet where its gravity dominates that of the central star
square sailer (or square-rigged sailer) - a sailing ship with an overall square form
stay - a rigging line
Sun synchronous - Sun-centered orbital motion where a sail or other craft maintains a constant position relative to a point on the Sun
swingby - see gravity assist
theta - angle between the resultant force vector and the radial from the light source