LightSail 2

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LightSail 2
Names LightSail-1[1]
Mission type Technology Demonstration
Operator The Planetary Society
Start of mission
Launch date H1 2018
Rocket Falcon Heavy
Launch site LC-39A, Kennedy Space Center
Contractor SpaceX

LightSail 2 is a project to demonstrate controlled solar sailing using a CubeSat, scheduled for launch no earlier than September 2017 and developed by The Planetary Society, a global non-profit organization devoted to space exploration.[2] The spacecraft core measures 10 by 10 by 30 centimeters, and its kite-shaped solar sail deploys into a total area of 32 square meters (340 sq ft).[3]

On May 20, 2015, a nearly identical demonstration spacecraft, LightSail 1 (formerly called LightSail-A[1]), was launched, and deployed its solar sail on June 7, 2015.


NASA's NanoSail-D with sail deployed.

In 2005, The Planetary Society attempted to send a larger solar sail named Cosmos 1 into space, but the spacecraft's Russian Volna launch vehicle failed to reach orbit.[4] In 2009, the Society began working on a CubeSat-based solar sail based on NASA's NanoSail-D project,[5] which was lost in August 2008 due to the failure of its Falcon 1 launch vehicle.[6] (A second unit, NanoSail-D2, was successfully deployed in early 2011.)

By 2011, the LightSail project had passed its critical design review, which was conducted by a team including JPL project veterans Bud Schurmeier, Glenn Cunningham, and Viktor Kerzhanovich, as well as Dave Bearden of Aerospace Corporation.[7] The original estimated cost of the LightSail project was US$1.8 million, which was raised from membership dues and private sources. The prototype spacecraft LightSail 1 (or LightSail-A) was built in San Luis Obispo by Stellar Exploration Inc.[4]

In March 2016, The Planetary Society announced they decided to use the convention on naming the spacecraft with the program name followed by a sequential number; the test flight or LightSail-A, became LightSail 1, and the upcoming larger spacecraft is now called LightSail 2.[1]


As a solar sail, LightSail 2's propulsion is dependent on solar radiation alone. Solar photons exert radiation pressure on the sail, producing a small degree of acceleration. Thus, the solar sail will be propelled by pressure from sunlight itself, and not by the charged particles of the solar wind.[8] The Planetary Society expects LightSail 2's orbit to increase by as much as a kilometer per day.[9]

A diagram showing LightSail 2's orbital configuration.


LightSail 2's modular design is based on a modular three-unit CubeSat, a small satellite format created for university-level space projects. One CubeSat-sized module carries the cameras, sensors and control systems, and the other two units will contain and deploy the solar sails.[10]

The spacecraft contains four triangular sails, which combine to form a rectangular-shaped surface. The sails are made of Mylar, a reflective polyester film.[11]

LightSail 1 flight[edit]

A preliminary technology demonstrator spacecraft, LightSail 1 (formerly LightSail-A[1]), was launched as a secondary payload aboard a United Launch Alliance Atlas V rocket at 15:05 UTC on 20 May 2015 from Cape Canaveral Air Force Station, Florida.[12][13][14] Though the mission delivered the satellite to an orbit where atmospheric drag was greater than the force exerted by solar radiation pressure, it allowed a full checkout of the satellite's systems in advance of the main mission at a higher orbit.[15]

Two days after the launch, however, the spacecraft suffered a software malfunction which made it unable to deploy the solar sail or to communicate.[16] On 31 May 2015, The Planetary Society reported having regained contact with LightSail 1.[17][18] After the solar panels were deployed on 3 June 2015, communications with the spacecraft were lost once more on 4 June. In this case, a fault with the battery system was suspected.[19] Contact was then reestablished on 6 June,[20] and the sail deployment was initiated on 7 June.[21] At a conference on 10 June 2015, after photos of deployment were downloaded, the test flight was declared a success.[22] The spacecraft reentered the atmosphere on 14 June 2015, ending the test flight.[23][24]

Lightsail 2[edit]

LightSail 2's goal is to test whether solar sails are a viable form of spacecraft propulsion for CubeSats. The spacecraft team will measure whether there is any increase in LightSail 2's altitude after the spacecraft is deployed from a partner spacecraft, Prox-1, at an altitude of 720 kilometers.[10] Prox-1 and LightSail 2 are secondary payloads aboard the first operational SpaceX Falcon Heavy launch, which will carry the STP-2 payload for the U.S. Air Force.[25]

See also[edit]


  1. ^ a b c d Davis, Jason (1 March 2016). "Meet LightSail 2, The Planetary Society's new solar sailing CubeSat". The Planetary Society. Retrieved 2016-03-01. 
  2. ^ Davis, Jason (March 3, 2017). "Signed, sealed but not delivered: LightSail 2 awaits ship date". The Planetary Society. Retrieved March 29, 2017. 
  3. ^ "LightSail". The Planetary Society. Retrieved 2017-03-29. 
  4. ^ a b Antczak, John (November 9, 2009). "After letdown, solar-sail project rises again". MSNBC. Associated Press. 
  5. ^ Dennis Overbye (November 9, 2009). "Setting Sail Into Space, Propelled by Sunshine". The New York Times. 
  6. ^ "SpaceX's Falcon 1 Falters For a Third Time". Retrieved 2017-03-29. 
  7. ^ Louis D. Friedman (June 25, 2010). "LightSail-1 Passes Critical Design Review". The Planetary Society. 
  8. ^ "Planetary Society To Sail Again With LightSail". Space Travel blog. November 10, 2009. 
  9. ^ "A Kilometer Per Day: LightSail Mission Managers Refine Orbit-Raising Plan". Retrieved 2017-03-29. 
  10. ^ a b "LightSail". The Planetary Society. Retrieved 2017-03-29. 
  11. ^ "Frequently Asked Questions". The Planetary Society. Retrieved 2017-03-29. 
  12. ^ "Mission Control Center". The Planetary Society. Retrieved 2015-05-22. 
  13. ^ Wall, Mike (10 May 2015). "Tiny Solar Sail 'Cubesat' Launching with X-37B Space Plane on Wednesday". Retrieved 2015-05-20. 
  14. ^ Davis, Jason (April 13, 2015). "LightSail Launch Delayed until at least May 20". The Planetary Society. 
  15. ^ Davis, Jason (January 26, 2015). "It's Official: LightSail Test Flight Scheduled for May 2015". The Planetary Society. 
  16. ^ Wall, Mike (27 May 2015). "LightSail Solar Sail Test Flight Stalled by Software Glitch". Retrieved 2015-05-29. 
  17. ^ Fingas, John. "LightSail solar spacecraft gets back in touch with its ground crew". Engadget. Retrieved 2015-05-31. 
  18. ^ "Bill Nye’s LightSail spacecraft is back in touch with Earth after rebooting itself". The Verge. 31 May 2015. Retrieved 2015-05-31. 
  19. ^ Davis, Jason (4 June 2015). "LightSail Falls Silent; Battery Glitch Suspected". Planetary Society. 
  20. ^ "LightSail Drama Continues as Spacecraft Wakes for Second Time". The Planetary Society. 2015-06-06. Retrieved 2015-06-06. 
  21. ^ Deployment! LightSail Boom Motor Whirrs to Life. 7 June 2015
  22. ^ LightSail Test Mission Declared Success; First Image Complete. 9 June 2015.
  23. ^ LightSail Solar Sail Ends Test Flight with Fall Back to Earth. Leonard David, 18 June 2015.
  24. ^ Molczan, Ted (2015-06-14). "LightSail-A: Post-Sail Deployment Orbital Elements". Retrieved 2015-06-15. 
  25. ^ Nye, Bill. Kickstart LightSail. Event occurs at 3:20. Retrieved 15 May 2015.