Uploaded May 2015 | Updated September 2026, 1 hour ago
Solar Sails
Fast and efficient space travel is essential to maximize our efforts in outer space, whether they be for exploration or one day, colonization. It is not efficient or practical to use spacecraft, which rely on thrusters and fuel in tanks. The weight of current spacecraft are 95% fuel at launch. One alternative to rockets are solar sails. Solar sails are large, thin, reflective structures that borrow the momentum of solar radiation photons and accelerate to very high speeds. With constant push from just the sun’s photons, a solar vehicle could potentially get a velocity up to 90 km/s. With the addition of a laser or magnetic beam transmitter, the top speed could be 30,000 km/s, one-tenth the speed of light . An effective solar sail would be approximately the size of Texas.
Structure: Sails, which make up the majority of the structure, can be greater than 100 meters on one side and are often made of a polyimide called Kapton that is coated with a layer of aluminum to give it reflective properties. Kapton, a polyimide film often made of the monomers pyromellitic dianhydride and 4,4’ oxydianiline. It is five microns thick and very lightweight. Kapton can be made into sheets of very large area (due to high tensile strength), which is essential to solar sails’ purpose; the more area they cover, the more sunlight is received and the faster they travel. It is formed from the synthesis of an aromatic dianhydride and an aromatic diamine. The result is an aromatic structure containing very stable molecules and resulting in bonds that are easy to make, but very hard to break.
Properties: Kapton is a good insulator, it has a long lifespan, and a tensile strength of 231 MPa at 23C. It also has a low density of 1.42 g/mL. Kapton is able to maintain these properties over a temperature range of -269 C to 400 C. This is a major issue with solar sails because exposure to direct solar radiation can cause much higher temperatures. When used in solar sails, the aluminum coating provides the reflective properties needed for movement. Above all, solar sails require a flexible material that is lightweight and can cover a large area, as the amount of sunlight received is proportional to the acceleration.
Processing: Kapton’s high resistance to temperature change leaves few viable processing options, with Digital Laser Material Processing (DLMP) being one of the best methods (youtube.com/watch?v=DAHtdZdpQZE). Aluminum coating is applied to kapton film by framing machines once the film has been cast to the right width. Usually the coefficients of thermal expansion between the aluminum and film don’t match, so the use of filler materials and chemistry can change the CTE for aluminum to match the kapton film.
Sources:
Freudenrich, Ph.D., C. (2001, April 6). How Solar Sail Technology Works. Retrieved March 6, 2015, from science.howstuffworks.com/solarsail1.htm
Harris, F.W., Polyimides, Ed. Wilson D., Stenzenberger, H.D., Hergenrother, P.M., Chapman and Hall, New York, 1990, Chapter 1.
NASA. (n.d.). Solar Sail Demonstration Project. Retrieved March 5, 2015, from nasa.gov/sites/default/files/files/Solar_Sail_TDM_Fact_Sheet.pdf
Kapton Summary of Properties. (n.d.). Retrieved March 5, 2015, from dupont.com/content/dam/assets/products-and-services/membranes-films/assets/DEC-Kapton-summary-of-properties.pdf
Polyimides: Chemistry & Structure-Property Relationships. (n.d.). Retrieved March 6, 2015, from http://scholar.lib.vt.edu/theses/available/etd-051799-162256/unrestricted/polyimide1.pdf
Spieth, D., & Zubrin, Ph.D., R. (1999, December 1). Ultra-thin Solar Sails for Interstellar Travel. Retrieved March 5, 2015, from http://www.niac.usra.edu/files/studies/final_report/333Christensen.pdf
Wall, M. (2014, May 27). Are Solar Sails the Future of Space Travel? | Space.com. Retrieved March 5, 2015, from space.com/26011-solar-sail-tech-space-exploration.html
pslc.ws/macrog/imide.htm
Team Members:
Bethany Gordon
Hannah Becker
Griffin Battel
Declan Prendergast
Solar Sails
Fast and efficient space travel is essential to maximize our efforts in outer space, whether they be for exploration or one day, colonization. It is not efficient or practical to use spacecraft, which rely on thrusters and fuel in tanks. The weight of current spacecraft are 95% fuel at launch. One alternative to rockets are solar sails. Solar sails are large, thin, reflective structures that borrow the momentum of solar radiation photons and accelerate to very high speeds. With constant push from just the sun’s photons, a solar vehicle could potentially get a velocity up to 90 km/s. With the addition of a laser or magnetic beam transmitter, the top speed could be 30,000 km/s, one-tenth the speed of light . An effective solar sail would be approximately the size of Texas.
Structure: Sails, which make up the majority of the structure, can be greater than 100 meters on one side and are often made of a polyimide called Kapton that is coated with a layer of aluminum to give it reflective properties. Kapton, a polyimide film often made of the monomers pyromellitic dianhydride and 4,4’ oxydianiline. It is five microns thick and very lightweight. Kapton can be made into sheets of very large area (due to high tensile strength), which is essential to solar sails’ purpose; the more area they cover, the more sunlight is received and the faster they travel. It is formed from the synthesis of an aromatic dianhydride and an aromatic diamine. The result is an aromatic structure containing very stable molecules and resulting in bonds that are easy to make, but very hard to break.
Properties: Kapton is a good insulator, it has a long lifespan, and a tensile strength of 231 MPa at 23C. It also has a low density of 1.42 g/mL. Kapton is able to maintain these properties over a temperature range of -269 C to 400 C. This is a major issue with solar sails because exposure to direct solar radiation can cause much higher temperatures. When used in solar sails, the aluminum coating provides the reflective properties needed for movement. Above all, solar sails require a flexible material that is lightweight and can cover a large area, as the amount of sunlight received is proportional to the acceleration.
Processing: Kapton’s high resistance to temperature change leaves few viable processing options, with Digital Laser Material Processing (DLMP) being one of the best methods (youtube.com/watch?v=DAHtdZdpQZE). Aluminum coating is applied to kapton film by framing machines once the film has been cast to the right width. Usually the coefficients of thermal expansion between the aluminum and film don’t match, so the use of filler materials and chemistry can change the CTE for aluminum to match the kapton film.
Sources:
Freudenrich, Ph.D., C. (2001, April 6). How Solar Sail Technology Works. Retrieved March 6, 2015, from science.howstuffworks.com/solarsail1.htm
Harris, F.W., Polyimides, Ed. Wilson D., Stenzenberger, H.D., Hergenrother, P.M., Chapman and Hall, New York, 1990, Chapter 1.
NASA. (n.d.). Solar Sail Demonstration Project. Retrieved March 5, 2015, from nasa.gov/sites/default/files/files/Solar_Sail_TDM_Fact_Sheet.pdf
Kapton Summary of Properties. (n.d.). Retrieved March 5, 2015, from dupont.com/content/dam/assets/products-and-services/membranes-films/assets/DEC-Kapton-summary-of-properties.pdf
Polyimides: Chemistry & Structure-Property Relationships. (n.d.). Retrieved March 6, 2015, from http://scholar.lib.vt.edu/theses/available/etd-051799-162256/unrestricted/polyimide1.pdf
Spieth, D., & Zubrin, Ph.D., R. (1999, December 1). Ultra-thin Solar Sails for Interstellar Travel. Retrieved March 5, 2015, from http://www.niac.usra.edu/files/studies/final_report/333Christensen.pdf
Wall, M. (2014, May 27). Are Solar Sails the Future of Space Travel? | Space.com. Retrieved March 5, 2015, from space.com/26011-solar-sail-tech-space-exploration.html
pslc.ws/macrog/imide.htm
Team Members:
Bethany Gordon
Hannah Becker
Griffin Battel
Declan Prendergast
