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Short History of Photonic Propulsion

Illustrations de Theatri cometici pars posterior. Sive historia cometarum a' diluvio ad A. C. 1665 - Stanislaw de Lubienietz, Editeur Apud Franciscum Cuyperum (Amstelodami), 1667.

From the initial observations and assumptions made by Kepler in 1619 to the launch of Ikaros in 2010, the history of the photonic propulsion covers nearly four centuries. This mode of propulsion, still often seen as original or unusual, yet relies by some aspects, on more intuitive principles than for the jet engine, and evokes  the image of sailing. No doubt that it is the reason why history of solar sails, while being closely associated with science and technology, possesses a particular dimension where  imagination and fiction hold an important place. The chronology of this history can be structured in 4 milestones : observations, formalisations, fictions, and missions.

It was not until the theoretical work of Maxwell about electromagnetism, published in 1873 (9), that the principle of the photonic pressure was formalized, Maxwell's equations showing that the light does not propagate only energy, but also constant linear momentum.

The experimental demonstration is made by the russian physicist Piotr Lebedev in the laboratories of the state university of Moscow. He highlights the effect of light pressure on solid bodies in 1899 - the results were announced at the World Congress of Physics in Paris in 1900 - then on gases in 1907. These experiments will be confirmed in the United States in 1903 by the works of G.F. Hull and Ernest Fox Nichols of Dartmouth University.

In the early 1920s Konstantin Tsiolkovsky will consider the use of this pressure as a method of propulsion. It is to  Friedrich Tsander - who is in contact with Tsiolkovsky - that is generally attributed the first formalization of the concept of the solar sail in 1924 (10). He will mention "for interplanetary space flights [...] the idea of tremendous mirrors made extremely thin sheets [..]."

In 1961, the french science fiction author Gérard Klein, under the pseudonym of Gilles Argyre, publishes  « Les voiliers du soleil »/« The sailboats of the sun »  (aux éditions Fleuve Noir - n° 172, Collection Anticipation) that he claims to be the first novel dedicated to the solar sails.

Jack Vance, on the mode of space opera, describes in 1962 the flight of a solar sailboat on the way to Mars in «Gateway to Strangeness - Sail 25) for the magazine Amazing Stories - with on the cover a Robert McCall' s illustration (who will realize later the movie poster of 2001 Space Odyssey and numerous paintings for the NASA).

But the short story the most concerned with scientific realism is probably the one of A.C.Clarke « The Wind From the Sun » ( 1963 ). First Publisher under the title Sunjammer in the science fiction magazine Boy's Life, it depicts a solar yacht race from the Earth to the Moon. This short story will inspire later, in 1992, the musician  Mike Oldfield for the title Sunjammer Tubular Bell II.

Illustration from « Aventures extraordinaires d’un savant russe »

Les voiliers du Soleil, Gérard Klein alias Gilles d’Agyre, 1961.

The effect of the pressure of sunlight is clearly demonstrated in experiments on the reflection of electro magnetic waves conducted in 1960 by the NASA with the passive satellite Echo-1 (balloon made of mylar  30 meters diameter). In the following years, the space agency has pursued technological studies on the photonic propulsion, but without any reference to a particular mission.

It is really in the 70s that practical applications will be considered when concrete applications are envisaged. During the flight of Mariner -10 on the way to Mercury after its passage near Venus, the Jet Propulsion Laboratory’ s engineers decided to use the photonic pressure exerted on the solar panels of the space probe in order to extend the life of the mission, what  will allow to make a total of three fly over of the planet in September on 1974  (13).

L’arche de lumière,

Jacques Rougerie

Russian mirror

Znamya 2

At the end of the 80s, other projects concerned with the strong symbolic dimension of solar sails are envisaged - will never see the light of day -, with  "Columbus 500", whose objective is to organize on a similar mode a solar sails race to Mars to celebrate in 1992 the anniversary of the discovery of America ; or the ARSAT’s inflatable structures project, joining the artistic approach of the plastician artist Pierre Comte. The french architect Jacques Rougerie will also be interested  in the solar sails by proposing the Arch of Light.

Spartan antenna

Solar sails projects multiply in the 2000s, as well within space agencies as in academic and associative circles. With private funds the Planetary Society (15) manages to launch Cosmos 1 the 21 juin 2005, sail of a hundred kg and 30 meters  diameter, composed of 8 triangular "blades" , and a total surface of 600 m2. The launcher - Volna a decommissionned missile launched from a Russian submarine in the Barents Sea - encounters an engine failure shortly after takeoff, and unfortunately the mission cannot be achieved. The person in charge of the project, Louis Friedman, restart a new program -  currently underway - within the framework of Planetary Society -  Lightsail - one of a serie of three satellites whose last model is intended to demonstrate, just like Vigiwind, the feasibility of a monitoring system of solar flares.

Japanese test of deployment, 9 août 2004

The effective launch of the first solar sail is made by the Japanese Space Agency JAXA. On 9 August 2004, the Institute of Space and Astronautical Science ISAS, (now part of JAXA), had succeeded in testing the opening of a sail during a ballistic flight launched from the space center of Uchinoura - and it is almost six years later, on May 21 2010, that the "Solar Power Sail" Ikaros is launched and deployed successfully in space June 10th.

Ikaros is a square sail made of polyimide 7.7 microns thick and a diameter of 20 meters for a mass of about 300 kg, combining photonic propulsion and,eventually later an ion engine powered by energy collected on the sail itself through solar cells. Its originality lies also in its attitude control system, using strips of liquid crystals arranged on the lateral edges of the sail, whose index of reflection can be electrically controlled..



Today other projects are oriented/turned to the potential/possibilities offered by  nano-satellites, designed around structures Cubsat type. This is the case of the micro-sail NanoSail-D2, ejected into space by NASA  from the satellite FastSat on December 6th 2010, currently the second solar sail in orbit around the earth. Or projects presently pursued by U3P  with - Libellule-Dragonfly - or Cubsail by the University of Surrey (UK) supported by EADS Astrium.

(13) It is often said that Mariner 10 was the first operational use of photonic pressure for a space mission. This is not quite true (cf. B. Murray). The idea to make a second fly by/fly over of Mercury in playing over/on/with the resonance (2:1) between the period of the Mariner 10 and Mercury, is from Giuseppe Colombo (in honor of whom was named the ESA mission to Mercury).

The other one to orientate Mariner-10, so that the effect of photonic pressure allows a third flying over Mercury by the probe, once ergols enabling the stabilization of the probe are exhausted, comes from engineers of the JPL. The idea, which has been afterward widely picked up for the stabilization of  telecommunications satellites  in particular, is to balance the satellite by cancelling the couple due to photonic pressure, this is in orienting properly some movable appendages (generally antennas).

It is therefore indirectly and not by a direct effect of propulsion that the third fly fly over of Mercury by Mariner 10 has been made with photonic pressure.

Nevertheless, it is this JPL’s engineers team who, a few years later, proposed to use the photonic pressure this time to navigate through space, the goal was to accompany the Halley’s comet during its passage in 1986 .

De Cometis Libelli Tres, Johannes Kepler, 1619.

However, concepts are still  missing to prove the existence of a pressure exerted by the sunlight : Descartes himself in 1644 tried to build a complex theory to explain the formation and orientation of the comets‘s tail (6). His hypotheses in favor of the wavelike nature of light on one hand, and the necessity for any force to result from mechanical action on the other hand, did not allow/made it impossible for him to conclude about the existence of the sunlight light pressure. He attributed the phenomenon to the effect of "a new kind of refraction we do not notice in earthly bodies" (7). Newton will refute this theory, like Voltaire and Emilie du Châtelet in « Elements of the Philosophy of Newton » published in 1737 (8).

Illustration from Principes de la philosophie, Descartes, 1644.

While in the seventeenth century the debate on the nature and origin of comets raises many speculations, Kepler publishes in 1619 De Cometis Libelli Tres (1), in which he emphasizes the link between the orientation of the sunlight and the comets‘s tail : "So, as it is obvious that the tail of comets is formed by the sun’s rays, it can reasonably be said, that the material that the sun’s rays pull out from the body of the comet is present in the tails - or beards - of comets. And when the material flow has been located, the curvature of the tail can occur in various directions from a straight line opposite to the sun. «Tres De Cometis Libelli », 1619 (cf. Frisch edition, VII, 110) (2).

A few years earlier in a letter sent in 1610 to Galilee - and although it is more reasonable to see a metaphor rather than a real intuition about the photonic propulsion - he evokes the man’s possibility to travel in the future in the solar system aboard  " ships and sailboats taking advantage of celestial breezes " (5).

The popular scientific works of Yakov Perelman will, at the same time, contribute to spread this idea, especially in « The interplanetary journey » , as he approaches - among others modes of propulsion - the photonic propulsion (11).

Another pioneer of astronautics, Hermann Oberth suggests  otherwise not solar sails themselves, but at least the possibility to build huge solar mirrors in The space travel (Die Raumschiffahrt) in 1929.

Richard Garwin - a consultant to the U.S. Army, IBM Watson Laboratory - published in 1958 the first article devoted entirely to the photonic propulsion in the scientific journal Jet propulsion. There he develops in particular the principle of navigation on a spiral trajectory towards the sun.

But it is a few years earlier, in 1951, that the American engineer Carl Wiley - under the pseudonym Russell Saunders - published in the famous science fiction magazine Astounding Science Fiction, the article « Clipper Ships of Space » considered by many authors (12) as the first serious technological approach of solar sails : « A fascinating suggestion for sailing ships of space, a seemingly wild notion, but actually worked out mathematically, it makes sense ! It would be possible to sail on the wind that blows between the worlds ».

Other developments follow in the 50s, particularly those of Ted Cotter - scientist of the laboratories of Los Alamos - who will propose the concept of rotating solar sail (spinning sail).

Not being easily implemented on the surface of the earth - unlike the jet engine - the speculations on the photonic propulsion are many in science fiction, through articles, novels and short stories whose authors are sometimes scientists signing under a pseudonym.

It was probably only an intuition, but Jules Verne from 1865 in « Voyage de la Terre à la Lune »/« From the Earth to the Moon », during a reflection on the modes of spatial propulsion, raises the question: " I ask you if there, there is a matter to get  ecstatic, and is not it obvious that all this will be outdated some day by even faster speeds, of whom light or  electricity will be probably the mechanical agents ?

With a naive style, H. Graffigny and Georges Le Faure in 1889 in « Extraordinary adventures of a russian scientist » , conceive an imaginary vehicle halfway between the boat and the solar mirror.

The evocation of solar sails is more explicit in the short story of Cordwainer Smith, « The Lady Who Sailed The Soul », published in Galaxy Magazine in 1960. Hiding Behind this pseudonym is Paul M. A. Linebarger, a scientist and an intelligence officer in the U.S. Army. He will resume the idea in 1963, in the short story « Think Blue », Count Two (Galaxy Magazine, in February, 1963, Volume 21, No. 3) :

« Before the great ships whispered between the stars by means of planoforming, people had to fly from star to star with immense sails -- huge films assorted in space on long, rigid, coldproof rigging. A small spaceboat provided room for a sailor to handle the sails, check the course, and watch the passengers who were sealed, like knots in immense threads, in their little adiabatic [temperature-constant] pods which trailed behind the ship. The passengers knew nothing, except for going to sleep on earth and waking up on a strange new world forty, fifty, or two hundred years later. This was a primitive way to do it. But it worked. »

It was also in 1963 that Pierre Boulle, in « La planète des Singes »/« Planet of the Apes »  mentions solars sails at the beginning of his novel, however they are missing in the film of FJ Schaffner (1968) : "At this time, interplanetary travel were common, but still intersideral travels were exceptional. Rockets were taking tourists to prodigious sites. They roamed the world for their pleasure - sailing. Their ship was  a kind of a sphere whose envelope  - the sail -  miraculously thin and light, moved in space, driven by the pressure of luminous radiations ".

From the 70s, the solar sails became a "classic"  theme of science fiction, treated by many authors. We can quote among them Larry Niven and Jerry Pournelle with « The Mote in God’s Eye » (translated into french under the title « The dust in God's eye »/« la poussière dans l‘œil de Dieu ») in 1974 ; George R. R. Martin and Lisa Tuttle's  with « Windhaven » in 1981) ;  and Robert Forward with « The Flight of the DragonFly » in 1984, imagining a giant photonic sailboat powered by a laser beam for a journey of 20 years to destination of Barnard Star. As a scientist, R. Forward will also publishes besides theoretical works developing this idea, as well as the possibility of using the photonic pressure for "levitate" the satellites on  atypical orbits.

In 1990, the various aspects of photonic propulsion will be presented through articles and science fiction short stories in «Project Solar Sail » , published by Arthur C. Clarke and David Brin for the World Space Foundation (WSF).

As the short story of  A.C. Clarke  - Poul Anderson, In 1964,  in a novel entitled Sunjammer, also tries a detailed and realistic description of sailing boats - : "The sail nearly bisected the sky now, four and a half miles across. The foam-filled members that stiffened it were like Brobdingnagian spokes with its slow rotation. That disk massed close to two tons, and yet it was ghostly thin, a micron's breadth of aluminized polymer. . . .They cost money to build, out in free space, yet far less than a powered ship; for they required no engines, no crews, no fuel, simply a metal coating sputtered onto a sheet of carbon compounds, a configuration of sensors and automata, and a means to signal their whereabouts and their occasional needs. Those needs rarely amounted to more than repair of some mechanical malfunction ».

At the same time, a first mission is conceived for a solar sail imagined at the instigation of Jerome Wright - then engineer at the Battelle Memorial Institute Ohio - who proposes the idea of space rendez vous with the Halley's comet  for its passage in 1986. The J.P.L, under the direction of Bruce Murray, undertakes the project in 1977 whose steering will be assured by Louis Friedman.  The feasibility of the concept is demonstrated, but the NASA gives up finally, estimating the deadline too close for a launch in 1981 or 1982. Afterward, several engineers of the J.P.L  create the World Space Foundation to continue these works on solar sails under private framework.

In France, in 1981, was created on the initiative of space field engineers, the Union for the Promotion of Photonic Propulsion (U3P), an association whose purpose was to organize a race of solar sails from the Earth to the Moon - idea that the association will rediscover later in the short story of Arthur C. Clarke, written twenty years earlier, « the Wind from the Sun » and then will make its first translation to french. If this project was on several occasions about to succeed/ - particularly in the middle of the 80s with the support of the Midi-Pyrénées Regional Council  that/which will not finally concretize its commitments - it has not been realized yet and remains relevant today.

1 - Observations

2 - Formalisations

3 - Fictions

First publication of d’A.C.Clarke Sunjammer dans Boy’s Life, 1963.

Amazing Stories, Gateway to Strangeness, Jack Vance, 1962.

Project Solar Sail, Arthur C.Clarke, 1990.

4 - Missions

Light structures prefiguring again solutions for the deployment of sails, were tested in May 1996 from the American shuttle Endeavour, with the inflatable antenna Spartan.

During the 90s, the German Space Agency DLR developed with NASA, Odissee, a square sail prototype  40 meters side with a mass of about 100 kg, that would be launched in geostationary orbit from a rocket Ariane 5.

Although this is not strictly speaking a solar sailboat, the techniques of deployment in the space of the circular large-sized sail-mirror (20 meters diameter) Znamya 2 are successfully experimented on February 4th 1993, from an automatic spaceship, Progress, in connection with the MIR station, thanks to the Russian engineer Vladimir Syromiatnikov in the Framework of the Reggata Space Consortium (14).

Theoretical studies focusing on applications of photonic propulsion continued especially in France within the framework of the Vigiwind project, conceived  by Jean-Yves Prado (CNES), intended to keep on a stable trajectory - thanks to a solar sail - an observation  satellite near the orbit of Mercury constantly maintained in the alignment of the earth, to monitor the inflow of particles coming from solar flares.

A second mission is planned in the coming months, with a sail of 50 meters diameter, for a flight to Jupiter and Trojan planets.

Notes :

(1) From Cometis Libelli Tres, Johannes Kepler, 1619. Digital version of the original edition download from the Website : http://www.e-rara.ch/zut/content/titleinfo/272385

(2) translation of the original Latin text taken from « L’essayeur Galilée » de Christiane Chauviré, litterary annals of the University of Besançon - Les Belles Lettres, Paris, 1980. - Page 252.

(3) Quoted in « History of modern astronomy » , Jean Sylvain Bailly, 1785. "The common opinion believed to see these comet‘s tails always directed in opposite direction to the earth. Pierre Appian, who saw better in this respect, showed that they were opposed to the sun. His remark was confirmed by all observers, and Tycho himself, with the difference however that he believed to have noticed a deflection. "

Voltaire's Elements of the philosophy of Newton also recalls the first/early observations of Peter Appian (Chapter XIII - Of Comets) : "The situation of this light, which varies in relation to us, is always the same in relation to the sun, it is always opposed to this star, and this truth was known since the sixteenth century ; it was discovered by Pierre Appian. "

(4) Modern encyclopedia, or abridged sciences literature and arts dictionary, M. Courtin, Bureau de l‘Encyclopédie, Paris 1825, page 556.

(5) Quoted particularly by Paul Gilster, Centauri Dreams, « Imagining and planning interstallar exploration« , Springer Science, 2004. Extract from Kepler's letter to Galileo : "There will certainly be no lack of human pioneers when we have mastered the art of flight ... Let us create vessels and sails adjusted to the heavenly breezes, and there will be plenty of people unafraid of the empty wastes. In the meantime, shall we prepare for the brave-sky maps of travelers' bodies celestial. Shall I do it for the moon, you Galileo, for Jupiter. "

(6) Principles of the Philosophy, Third part, Descartes. P. 358: " […] it appears always towards the opposite side of the sun. So that if the earth meets exactly in a straight line between the comet and the sun, this light also spreads  all sides around the comet ".

(7) Ibid., P.358 - 134. What about the refraction which makes appear the tail of comets : "For this, I must explain a new kind of refraction, whose I have not spoken in dioptrie, because one cannot notice it  in the eterrestrial bodies. "

(8) « Elements of natural philosophy of Newton » , Voltaire (and Emilie du Châtelet), 1739. Chapter XII: « Descartes was mistaken in explaining tails of comets, he claimed that it was a refraction of the light from these celestial bodies. Only one reflection reverses this system. Planets have much more light than comets : they should therefore have tails, hair, beards much longer ; they have none at all. This explanation of Descartes is slightly false. Newton adds to this argument against Descartes another objection no less decisive : if the refraction of light reflected from comets’s body caused these streaks of light, one should see different colors, whereas the big inequality of refractions in the length of these tails ».

(9) A treatise on Electricity and Magnetism,

(10) Quoted in : Solar Sailing: technology, dynamics, and mission applications, Pringer ed., Collin Mac Innes, 1999.

(11) Quoted in Russian Planetary Exploration, History, Development, Legacy and Prospects, Brian Harvey, Springer ed., 2007

(12) In particular Louis Friedmann, in  Starsailing : Solar Sails and Interstellar Travel, John Wiley & Sons,1988.

(14) The Regatta Space Consortium (SRC), was created in 1990 by RSC Energia Russian and various space domain organizations spatial to develop the experimental program Znamya ("the flag"). SBC was led by Yuri P. Semenov, Nicolai Sevastyanov et Vladimir Syromiatnikov.

(15) The Planetary Society was founded in 1980 by Carl Sagan, Bruce Murray and Louis Friedman.

This observation was not new, Charles Quint’s astronomer, Pierre Appien (3) formulated it for the first time in the previous century when passages of comets occurred between 1531 and 1539 (4). Kepler himself tried, beyond these observations, to establish a causal link between the phenomenon and the effect of sunlight.

Redactor: Olivier Boisard

Excerpt from a report by :

O.Boisard, B.Charles,

A.Delehelle, G.Pignolet et JY. Prado.

Thanks to Nicole  Doutre for the translation