Cosmos 1 was a project by Cosmos Studios and The Planetary Society to test a solar sail in space. As part of the project, an unmanned solar sail spacecraft christened Cosmos 1 was launched into space at 15:46:09 EDT (19:46:09 UTC) on June 21, 2005 from the submarine Borisoglebsk in the Barents Sea. However, a rocket failure prevented the spacecraft from reaching its intended orbit. Once in orbit, the spacecraft was supposed to deploy a large sail, upon which photons from the Sun would push, thereby increasing the spacecraft's velocity (the contributions from the solar wind are similar, but of much smaller magnitude).

Had the mission been successful, it would have been the first ever orbital use of a solar sail to speed up a spacecraft, as well as the first space mission by a space advocacy group. The project budget was US$4 million. The Planetary Society planned to raise another $4 million for Cosmos 2, a reimplementation of the experiment provisionally to be launched on a Soyuz resupply mission to the International Space Station. The Discovery Channel was an early investor. However, advances in technology and the greater availability of lower mass piggyback slots on more launch vehicles led to a redesign similar to NanoSail-D, called LightSail-1, announced in November 2009.

In the general sense, a cosmos is an orderly or harmonious system. It originates from the Greek term κόσμος (kosmos), meaning "order" or "ornament" and is antithetical to the concept of chaos. Today, the word is generally used as a synonym of the Latin loanword "Universe" (considered in its orderly aspect). The word cosmetics originates from the same root. In many Slavic languages such as Russian and Bulgarian, the word Космос cosmos means also the "outer space". In Mandarin Chinese, cosmos and universe are both translated as 宇宙 yuzhou, which literally translated means space-time (宇 yu = space + 宙 zhou = time).

Pythagoras is said to have been the first philosopher to apply the term cosmos to the Universe, perhaps referring to the starry firmament.

Russian cosmism is a cosmocentric philosophical and cultural movement that emerged in Russia in the early 20th century.

Cosmicism is a philosophical position that mankind is an insignificant aspect of a universe at best indifferent and perhaps hostile. This philosophy, explored by writers such as H.P. Lovecraft (who some say is the original proponent of the philosophy) and later writers who actually represented the beliefs in books such as Hitchhiker's Guide to the Galaxy.