''Sunjammer'' (Solar Sail Demonstrator) was a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

mission intended to demonstrate a

solar sail Solar sails (also known as light sails and photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been p ...

constructed by

LGarde LGarde, also L'Garde or L·Garde, is an American aerospace and defense technology company founded in 1971 in Orange County, CA and is the primary contractor for the Sunjammer spacecraft, the world largest solar sail. The company was an early ...

, but was canceled before launch. The largest solar sail made as of 2013, ''Sunjammer'' was named after a 1964 Arthur C. Clarke story of the same name, '' Sunjammer'', in which several solar sails compete in a race to the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. ''Sunjammer'' was slated to launch in January 2015 as the secondary payload of a

SpaceX Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...

Falcon 9 Falcon 9 is a partially reusable medium lift launch vehicle that can carry cargo and crew into Earth orbit, produced by American aerospace company SpaceX. The rocket has two stages. The first (booster) stage carries the second stage and payl ...

launch vehicle, along with the

Earth observation satellite An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, me ...

DSCOVR Deep Space Climate Observatory (DSCOVR; formerly known as Triana, unofficially known as GoreSat) is a National Oceanic and Atmospheric Administration (NOAA) space weather, space climate, and Earth observation satellite. It was launched by Space ...

. Citing a lack of confidence in its contractor's ability to deliver, the mission was canceled in October 2014.

Spacecraft design

Constructed of

Kapton Structure of poly-oxydiphenylene-pyromellitimide Kapton insulating pads for mounting electronic parts on a heat sink Kapton is a polyimide film used in flexible printed circuits (flexible electronics) and space blankets, which are used on spac ...

in order to withstand the extreme temperatures of space, ''Sunjammer'' has a width and height of , giving it a total surface area of over and making it the largest solar sail as of 2013. Despite its huge surface area, ''Sunjammer'' has a thickness of only 5 μm, giving it an extremely low weight of about and allowing it to be stored in a space the size of a dishwasher. Once in space, the large surface area of the solar sail would allow it to achieve a thrust of about 0.01 N and a characteristic acceleration of about 0.25 mm/s². To control its orientation, and via this its speed and direction, ''Sunjammer'' was to use gimballed vanes (each of which is itself a small solar sail) located at the tips of each of its 4 booms, instead of thrusters, eliminating the need for any propellant other than the rays of the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

. In addition to being a demonstration craft, ''Sunjammer'' was to collect scientific data in its own right. With several instruments to detect various aspects of

space weather Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the ma ...

, ''Sunjammer'' could have eventually become part of a larger network of solar sails studying the Sun, allowing for the creation of a more robust early-warning system for space weather.

Mission

Prior to its cancellation, ''Sunjammer'' was slated for launch in January 2015 aboard a Falcon 9 launch vehicle, a slight delay from an earlier projection of November 2014. It was to launch as a secondary payload along with the primary DSCOVR Earth observation and space weather satellite. Within two months of launch the spacecraft was to test various technologies, such as deployment, vector control via altitude vanes, and eventually reaching a location near the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

L1 Lagrange point.

Payloads

Sunjammer was to carry two British space science payloads: the Solar Wind Analyser (SWAN) developed by the

Mullard Space Science Laboratory The UCL Mullard Space Science Laboratory (MSSL) is the United Kingdom's largest university space research group. MSSL is part of the Department of Space and Climate Physics at University College London (UCL), one of the first universities in the ...

University College London , mottoeng = Let all come who by merit deserve the most reward , established = , type = Public research university , endowment = £143 million (2020) , budget = ...

, and the MAGIC magnetometer developed by the

Blackett Laboratory The Blackett Laboratory is part of the Imperial College Faculty of Natural Sciences and has housed the Department of Physics at Imperial College London since its completion in 1961. Named after experimental physicist Patrick Blackett who establi ...

Imperial College London Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...

.Sunjammer spacecraft to 'sail' towards the sun - Telegraph
/ref> Sunjammer was to carry a Celestis Memorial Spaceflight payload of cremated remains.

References

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External links

Sunjammer Solar Sail Mission
Sunjammermission.com web site
Sunjammer
L'Garde Inc. Sunjammer page

NASA Sunjammer Mission page
The Sunjammer Solar Sail: Making Your Loved One Part of Space History
Celestis Sunjammer page
Sunjammer
Space and Atmospheric Physics Group, Imperial College London Solar sail spacecraft Satellites of the United States Cancelled spacecraft Projects disestablished in 2014

Spacecraft design

Mission

Payloads

See also

References

External links