Sunjammer (spacecraft)

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Sunjammer as seen from the top of the vacuum chamber where it was tested
NamesSolar Sail Demonstrator
WebsiteThe Sunjammer Project
Spacecraft properties
Launch mass32 kilograms (70 lb)
Dimensions124 by 124 feet (38 by 38 m)
Start of mission
Launch dateCancelled (planned for January 2015 (2015-01))
RocketFalcon 9
Launch siteCape Canaveral Air Force Station

Sunjammer (Solar Sail Demonstrator) was a NASA mission intended to demonstrate a solar sail constructed by LGarde, but was cancelled before launch. The largest solar sail made as of 2013, Sunjammer was named after a 1964[1] Arthur C. Clarke story of the same name, Sunjammer, in which several solar sails compete in a race across the Solar System.[2] Sunjammer was slated to launch in January 2015 as the secondary payload of a SpaceX Falcon 9 rocket, along with the Earth observation satellite DSCOVR.[2] Citing a lack of confidence in its contractor's ability to deliver, the mission was cancelled in October 2014.[3]

Spacecraft design[edit]

Constructed of Kapton in order to withstand the extreme temperatures of space, Sunjammer has a width and height of 38 metres (124 ft), giving it a total surface area of over 1,200 square metres (13,000 sq ft) and making it the largest solar sail as of 2013.[4] Despite its huge surface area, Sunjammer has a thickness of only 5 μm, giving it an extremely low weight of about 32 kilograms (70 lb) and allowing it to be stored in a space the size of a dishwasher.[4] Once in space, the large surface area of the solar sail would allow it to achieve a thrust of about 0.01 N—roughly the weight of a sugar packet.[5] 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, completely eliminating the need for any propellant other than the rays of the Sun.[5]

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, 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.[2]


Prior to its cancellation, Sunjammer was slated for launch in January 2015 aboard a Falcon 9 rocket, 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.[2] 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-Sun L1 Lagrangian point.[4]


Sunjammer was to carry two British space science payloads: the Solar Wind Analyser (SWAN) developed by the Mullard Space Science Laboratory of University College London,[6] and the MAGIC magnetometer developed by the Blackett Laboratory of Imperial College London.[7][8]

Sunjammer was to carry a Celestis Memorial Spaceflight payload of cremated remains.[9]

See also[edit]


  1. ^ Clarke, Arthur C. "Short Stories". Archived from the original on October 2, 2011. Retrieved June 14, 2013.
  2. ^ a b c d Wall, Mike (June 13, 2013). "World's Largest Solar Sail to Launch in November 2014". TechMediaNetwork. Retrieved June 14, 2013.
  3. ^ Leone, Dan (October 17, 2014). "NASA Nixes Sunjammer Mission, Cites Integration, Schedule Risk".
  4. ^ a b c David, Leonard (January 31, 2013). "World's Largest Solar Sail to Launch in November 2014". TechMediaNetwork. Retrieved June 15, 2013.
  5. ^ a b Brooke, Boen, ed. (December 16, 2011). "Solar Sail Demonstration (The Sunjammer Project)". Technology Demonstration Missions. NASA. Retrieved June 15, 2013.
  6. ^ Sunjammer team to present latest solar sail technology
  7. ^ Dr. Jonathan Eastwood, Imperial College London
  8. ^ Sunjammer spacecraft to 'sail' towards the sun - Telegraph
  9. ^ "SUNJAMMER MISSION PARTNERS ANNOUNCED for GIANT NASA SOLAR SAIL LAUNCH" (PDF). Press Release. June 4, 2013. Archived from the original (PDF) on September 9, 2013.

External links[edit]