History of Solar Sails
NASA's Nano-Sail D Project Failed, but Space Agency Will Try Again
Sep 6, 2008
Solar sails may seem like something out of a 40s pulp fiction magazine or Walt Disney's Treasure Planet, but NASA researchers believe they might be a viable method of space craft propulsion for some of their vehicles. A probe that was launched in August 2008 was designed to test the feasibility of solar sails. Unfortunately, the mission failed two minutes after being launched, according to the Nano-Sail D mission web page, but NASA touts the efforts of engineers beforehand as a success. The probe, however, is merely the latest in a long line of attempts to try using the sun's light to sail through the void of space.
The idea that the sun might provide energy that can be used to propel crafts originated with the German astronomer Johannes Kepler. Kepler saw that comets were affected by winds coming from the sun. He speculated that this solar breeze may propel comets through the solar system.
First Attempts at Solar Sailing
Kepler may have been wrong about the breezes emanating from the sun, but the light energy that the sun emits can be used to power vehicles in outer space. The first time this effect was demonstrated was in the 1960s by the probe Echo One. In the 1970s, the Mariner probe, which was low on fuels used its solar panels to control its attitude adjustment on Mercury. The original intent was for the probe to use fuel reserves to control its position, but the probe had used more fuel than expected and a NASA scientist returned to the idea of solar sails. He suggested using the panels the probe was equipped with to change the position of the Mariner spacecraft.
NASA would not experiment with solar sails again until the dawn of the next century, but the Russians and the Japanese experimented with using the protons from the sun as a method of propulsion. Russia's efforts would not be part of a propulsion system, but rather an attempt to use large mirrors to beam solar energy back down to earth. The first such probe, Znamya 2 was launched into space. Its mirrors unfolded and it sent a beam of light from the sun back down to the earth. The beam of light from the mirrors stretched across most of Europe, but Znamya 2 would suffer from flight control problems and the satellite crashed back to Earth.
Japanese and US Attempts at Solar Sails
The Soviet Union was not the only nation to experiment with what could be considered a solar sail. The aim of the Russian program was energy, but the goal of the Japanese program was to see if using the pressure applied on the sails by photons from the sun was a viable way to move a probe through the cosmos. The experimental probe of Japan's space agency would not enter outer space but the experimental probe did prove that solar sails were feasible method of spacecraft propulsion.
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