Solar sail
[5] James Clerk Maxwell, in 1861–1864, published his theory of electromagnetic fields and radiation, which shows that light has momentum and thus can exert pressure on objects.
[9] Svante Arrhenius predicted in 1908 the possibility of solar radiation pressure distributing life spores across interstellar distances, providing one means to explain the concept of panspermia.
[12] JBS Haldane speculated in 1927 about the invention of tubular spaceships that would take humanity to space and how "wings of metallic foil of a square kilometre or more in area are spread out to catch the Sun's radiation pressure".
"[14] Arthur C. Clarke wrote Sunjammer, a science fiction short story originally published in the March 1964 issue of Boys' Life [15] depicting a yacht race between solar sail spacecraft.
Carl Sagan, in the 1970s, popularized the idea of sailing on light using a giant structure which would reflect photons in one direction, creating momentum.
[16] The first formal technology and design effort for a solar sail began in 1976 at Jet Propulsion Laboratory for a proposed mission to rendezvous with Halley's Comet.
An actual sail will have an overall efficiency of about 90%, about 8.17 μN/m2,[24] due to curvature (billow), wrinkles, absorbance, re-radiation from front and back, non-specular effects, and other factors.
This is thus the distant point to which solar gravity will cause the region of deep space on the other side of the Sun to be focused, thus serving effectively as a very large telescope objective lens.
[30][31] It has been proposed that an inflated sail, made of beryllium, that starts at 0.05 AU from the Sun would gain an initial acceleration of 36.4 m/s2, and reach a speed of 0.00264c (about 950 km/s) in less than a day.
Spacecraft fitted with solar sails could also be placed in close orbits such that they are stationary with respect to either the Sun or the Earth, a type of satellite named by Forward a "statite".
On-board state-of-the-art accelerometers would measure shifts in the pressure differential between incoming solar and outgoing thermal radiation on opposing sides of each satellite.
Minor errors are greatly amplified by gravity assist maneuvers, so using radiation pressure to make very small corrections saved large amounts of propellant.
In the 1970s, Robert Forward proposed two beam-powered propulsion schemes using either lasers or masers to push giant sails to a significant fraction of the speed of light.
A planet-sized mirror or Fresnel lens would need to be located at several dozen astronomical units from the Sun to keep the lasers focused on the sail.
[46] In July 2015 British 3U CubeSat called DeorbitSail was launched into space with the purpose of testing 16 m2 deorbit structure,[47] but eventually it failed to deploy it.
[50] In June 2017 the 3U Cubesat URSAMAIOR has been launched in low Earth orbit to test the deorbiting system ARTICA developed by Spacemind.
The spacecraft's attitude and direction were to be completely controlled by changing the angle of the blades in various ways, similar to the cyclic and collective pitch of a helicopter.
[57] Designs differ, but most modify the metalization pattern to create a holographic monochromatic lens or mirror in the radio frequencies of interest, including visible light.
[57] The most common material in current designs is a thin layer of aluminum coating on a polymer (plastic) sheet, such as aluminized 2 μm Kapton film.
Sails in this class would offer high area per unit mass and hence accelerations up to "fifty times higher" than designs based on deploy-able plastic films.
[58] The material developed for the Drexler solar sail was a thin aluminium film with a baseline thickness of 0.1 μm, to be fabricated by vapor deposition in a space-based system.
A planetary swing-by could also be employed similar to what is done with coasting spacecraft, but good alignments might not exist due to the requirements for overall optimization of the trajectory.
On 21 May 2010, the Japan Aerospace Exploration Agency (JAXA) launched the IKAROS spacecraft, which deployed a 200 m2 polyimide experimental solar sail on June 10.
[86][87] The second backup version, NanoSail-D2, also sometimes called simply NanoSail-D,[88] was launched with FASTSAT on a Minotaur IV on November 19, 2010, becoming NASA's first solar sail deployed in low earth orbit.
[92] Despite the failed launch attempt of Cosmos 1, The Planetary Society received applause for their efforts from the space community and sparked a rekindled interest in solar sail technology.
The sail is held by a novel unfolding system of four 7 metres (23 ft) long carbon fiber reinforced polymer booms that roll-up for storage.
"[112] Despite the losses of Cosmos 1 and NanoSail-D (about 23cm x 23cm x 34cm) which were due to failure of their launchers, scientists and engineers around the world remain encouraged and continue to work on solar sails.
[123] In Larry Niven and Jerry Pournelle's 1974 novel The Mote in God's Eye, aliens are discovered when their laser-sail propelled probe enters human space.
In the third season of Apple TV+'s alternate history TV show For All Mankind, the fictional NASA spaceship Sojourner 1 utilises solar sails for additional propulsion on its way to Mars.
In the final episode of the first season of 2024 Netflix TV show, 3 Body Problem, one of the protagonists, Will Downing, has his cryogenically frozen brain launched into space toward the oncoming Trisolarian spaceship, using solar sails and nuclear pulse propulsion to accelerate it to a fraction of the speed of light.
