Nearly 400 years ago astronomer Johannes Kepler [
http://antwrp.gsfc.
] observed comet tails blown by a solar breeze [
http://www-spof.gsf
] and suggested that vessels might likewise navigate through space using appropriately fashioned sails [
http://science.nasa
prop08apr99_1.htm ]. It is now widely recognized that sunlight does indeed produce a force which moves comet tails [
http://antwrp.gsfc.
] and a large, reflective sail [
http://www1.msfc.na
photos00-150.htm ] could be a practical means of propelling a spacecraft [
http://www.planetar
]. In fact, the illustration above represents one concept explored by NASA [
http://www1.msfc.na
2000/00-150.html ] centers to develop an interstellar probe pushed along by sunlight [
http://www.ec-lille
] reflected from an ultrathin sail. Nearly half a kilometer wide, the delicate solar sail [
http://www.ugcs.cal
] would be unfurled in space. Continuous pressure from sunlight would ultimately accelerate the craft to speeds about five times higher than possible with conventional rockets [
http://antwrp.gsfc.
] -- without requiring any fuel! If launched in 2010 such a probe could overtake Voyager 1 [
http://vraptor.jpl.
], the most distant [
http://vraptor.jpl.
current.html#RTLT ] spacecraft bound for interstellar space, in 2018 going as far in eight years as the Voyager will have journeyed in 41 years.
Explanation
Nearly 400 years ago astronomer Johannes Kepler [
http://antwrp.gsfc.
] observed comet tails blown by a solar breeze [
http://www-spof.gsf
] and suggested that vessels might likewise navigate through space using appropriately fashioned sails [
http://science.nasa
prop08apr99_1.htm ]. It is now widely recognized that sunlight does indeed produce a force which moves comet tails [
http://antwrp.gsfc.
] and a large, reflective sail [
http://www1.msfc.na
photos00-150.htm ] could be a practical means of propelling a spacecraft [
http://www.planetar
]. In fact, the illustration above represents one concept explored by NASA [
http://www1.msfc.na
2000/00-150.html ] centers to develop an interstellar probe pushed along by sunlight [
http://www.ec-lille
] reflected from an ultrathin sail. Nearly half a kilometer wide, the delicate solar sail [
http://www.ugcs.cal
] would be unfurled in space. Continuous pressure from sunlight would ultimately accelerate the craft to speeds about five times higher than possible with conventional rockets [
http://antwrp.gsfc.
] -- without requiring any fuel! If launched in 2010 such a probe could overtake Voyager 1 [
http://vraptor.jpl.
], the most distant [
http://vraptor.jpl.
current.html#RTLT ] spacecraft bound for interstellar space, in 2018 going as far in eight years as the Voyager will have journeyed in 41 years.
Explanation