“Advanced civilizations may prefer electric sails to light sails. Abraham Loeb, a researcher at Harvard University’s Institute of Theory and Computing, recently answered a question that many people are curious about. A study by Manasvi Lingam, a researcher in the Department of Space Physics and Space Scienceate at the Florida Institute of Technology, found that electric sails are a better propulsion system than light sails near most stars.
Less-engineered propulsion spacecraft is a potential unit
“Most spacecraft today rely on jet propulsion engines, which produce counterforces, or thrust, through a large amount of gas spewing out at high speed. However, if spacecraft want to break out of the solar system and move into wider interstellar space, this highly engineered propulsion approach is clearly not cost-effective, and the ability to travel is limited by the amount of fuel it carries. Recently, Xie Wei, an associate professor at the Institute of Astronautics at Beijing Polytechnic University, said in an interview with Science and Technology Daily.
The medium material, which transforms heat and machinery into each other, can also be thought of as propellant or fuel. If you want to get rid of the limitations of the quality of work, we must find a way to “absorb energy” from the space environment, improve the ability to continue.
Xie told reporters that in recent years, more and more researchers have set their sights on less or even non-working propulsion methods, including the long-used light sails and “new generation” of magnetic sails and electric sails.
The concept of light sail has a long history, as early as the 1920s, some people began to think about how to “light and go”. Today, light sails have been successfully used in spacecraft, such as the United States of America’s Earth satellite “Light Sail 2”, Japan’s space probe IKAROS and so on. The working principle of the light sail is generally, the sun radiated photons hit the surface of the metal coating reflected, to achieve momentum exchange, to give the spacecraft the power to fly.
In addition to photons, plasma is common in space. Plasma is a whole of positive and negative charge particles with the same charge, which is electrically neutral in general.
In the 1990s, scholars came up with the idea of plasma and came up with the concept of a magnetic sail – a propulsion method that uses charged particles emitted by the sun to shift some momentum to spacecraft for acceleration in a fixed magnetic field.
At the beginning of the 21st century, the idea of electric sail came into being. The electric sail designed by the scholars is different from the flat-plated sails commonly found in the light sails and magnetic sails, starting with fishing nets and now preferring umbrella bone. The main structure of electric sail is mainly composed of “rope” of conductive aluminum wire. Each aluminum line is charged to generate power by resusing on charged particles in space.
Stealth and battery life at the same time
Light sails are large in size, move tens of kilometers, and are limited by photons, and in the dark places far from stars or obscured by other celestial bodies, the role of the sails is extremely limited. In contrast, magnetic and electric sails have the potential to sail deep in deep space. After all, almost all areas of space have charged particles.
Xie also agrees that alien civilizations may be more inclined to electric sails.
“Is there an alien?” Where are they? “This is a question that the astronomy community and even humans have been trying to find answers to. The Fermi paradox points out that scientific inferences can prove that aliens evolved much earlier than humans, that they should have come to Earth and exist somewhere, but so far, public information suggests that humans have found no evidence of the existence of aliens.
“Couldn’t it be aliens who have been here and haven’t been discovered?” No one knows the answer. Xie told reporters, at least at this stage of our cognitive range of light sails should not be the best choice for alien civilizations. Light sail’s ability to last for the time being, the working principle of reflected photons is doomed to light sail-powered spacecraft wherever they go, like a huge mirror – brilliant, bright. If extraterrestrial civilizations had evolved earlier and once skimmed over the Earth, we would not have been able to find out; if extraterrestrial civilizations had not yet evolved to the level we have, it would have not been so “high-profile” to detect other civilizations without confirming that the other is an enemy or friend.
Electric and magnetic sails, by contrast, are much more hidden. “Electric sails, in particular, rarely emit obvious detectable signals around them, and are a veritable space ‘shadow’. Xie said.
However, the thinness of only five charged particles in an average of one cubic centimeter space also raises concerns about the speed of the electric sail. It is well known that the distance of the universe is measured by light-years, which means that spacecraft can reach the speed of light at a magnitude of speed, and the voyage time can match the short life of mankind. You know, it took 35 years for voyage stoic voyage stoic situ at the first interstellar space probe in human history, Voyager 1.
Thin charged particles determine that the sail requires a lot of time acceleration. Mr Lingam said electric sails could eventually reach 0.1 times the speed of light by repeatedly approaching the star, but they estimated that it would take 10,000 “hits” over a million years, but that a million years was too long by the scale of human life.
“If there are long-lived species in the universe, electric sails are a very convenient and energy-efficient way to explore the Milky Way for millions of years. Lingam said.