Editing Cosmos 1 (section)

{{Short description|Solar sail project}}
{{About|the solar sail project and spacecraft|the Soviet satellite|Kosmos 1|the rocket|Kosmos-1}}
{{Use American English|date=November 2021}}
{{Use dmy dates|date=November 2021}}
{{Infobox spaceflight
| name              = Cosmos 1
| image             = Cosmos1 in orbit.jpg
| image_caption     = An artist's rendering of ''Cosmos 1'' orbiting the [[Earth]]
| image_size        = 300px

| mission_type      = [[Technology demonstration]]<ref name="Planetary">{{cite web|url=http://www.planetary.org/explore/topics/space_missions/private_missions/cosmos1.html|title=Private Mission - Cosmos 1
|publisher=The Planetary Society| archive-url=https://web.archive.org/web/20070929115043/http://www.planetary.org/explore/topics/space_missions/private_missions/cosmos1.html |archive-date=29 September 2007|access-date=21 November 2021}}</ref>
| operator          = [[The Planetary Society]]
| website           = 
| mission_duration  = Failed to orbit<br/>30 days (planned)

| spacecraft_bus    = 
| manufacturer      = The Planetary Society
| launch_mass       = {{cvt|100|kg}}
| dimensions        = {{cvt|30|m}} in diameter
| power             =

| launch_date       = 21 June 2005, 19:46:09 [[Coordinated Universal Time|UTC]]
| launch_rocket     = [[Volna]]
| launch_site       = [[Russian submarine K-496 Borisoglebsk|K-496 ''Borisoglebsk'']], [[Barents Sea]]
| launch_contractor = [[Makeyev Rocket Design Bureau]]

| entered_service   = 
| destroyed         = Failed to orbit
| last_contact      = 
| decay_date        =

| orbit_reference   = [[Geocentric orbit]] (planned)
| orbit_regime      = [[Low Earth orbit]]
| orbit_altitude    = {{cvt|800|km}}
| orbit_inclination = 80.00°
| orbit_period      = 
| apsis             = gee
}}

'''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 uncrewed solar-sail spacecraft named ''Cosmos 1'' was launched into space at 19:46:09 [[Coordinated Universal Time|UTC]] (15:46:09 [[Eastern Daylight Time|EDT]]) on 21 June 2005 from the submarine {{ship|Russian submarine|Borisoglebsk|K-496|2}} in the [[Barents Sea]]. However, a rocket failure prevented the spacecraft from reaching its intended orbit.<ref>{{cite news|title=Russians say solar-sail vehicle was lost|date=June 21, 2005|url=https://www.nbcnews.com/id/wbna8304717|publisher=Associated Press|website=NBC News|access-date=May 7, 2023}}</ref> Once in orbit, the spacecraft was supposed to deploy a large sail, upon which [[photon]]s from the [[Sun]] would [[Radiation pressure|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|space advocacy group]]. The project budget was US$4 million. The Planetary Society planned to raise another US$4 million for ''Cosmos 2'', a reimplementation of the experiment provisionally to be launched on a [[Soyuz (rocket family)|Soyuz]] resupply mission to the [[International Space Station]] (ISS). The Discovery Channel was an early investor.<ref>[http://www.planetary.org/programs/projects/solar_sailing/20080623.html Cosmos 2] {{webarchive|url=https://web.archive.org/web/20100421003559/http://www.planetary.org/programs/projects/solar_sailing/20080623.html|date=2010-04-21}}.</ref> 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.<ref name="LightSailRelease">{{cite web |url=http://www.planetary.org/about/press/releases/2009/1109_Planetary_Society_to_Sail_Again_with.html|title=LightSail Release|date=9 November 2009|publisher=The Planetary Society|access-date=26 April 2010}}</ref>