Translation guide
A solar sail is a spacecraft propulsion method using radiation pressure from sunlight on large reflective surfaces. This entry covers how to refer to the technology and its components in Japanese.
ソーラーセイル
solar sail (technology/spacecraft)
Referring to the concept of a solar sail as a propulsion system or a spacecraft that uses one.
The most common and direct loanword from English, widely used in scientific and popular contexts.
ソーラーセイルは太陽光の圧力で推進する。
A solar sail is propelled by the pressure of sunlight.
A native Japanese term literally meaning 'sun sail'. Used in technical and literary contexts, but less common than the loanword.
太陽帆の技術はまだ実験段階だ。
Solar sail technology is still in the experimental stage.
Literally 'light sail'. A more scientific term emphasizing the use of light pressure. Rarely used outside specialized literature.
光帆の原理は光子の運動量による。
The principle of the light sail is based on photon momentum.
Referring to the actual reflective sheet or membrane that catches sunlight.
Means 'solar sail membrane'. The most natural way to refer to the physical sail material.
ソーラーセイルの膜は非常に薄い。
The solar sail membrane is extremely thin.
Literally 'sail of the sun sail'. Redundant but sometimes used for clarity when distinguishing the sail from the whole spacecraft.
太陽帆の帆は反射率の高い素材でできている。
The sail of the solar sail is made of highly reflective material.
In most contexts, especially news, popular science, and casual conversation, ソーラーセイル is the safest choice. It is immediately understood and sounds natural.