Aluminum wire electronic sail - Aerospace Black Technology

Not long ago, NASA announced a very avant-garde and technologically advanced propulsion system for future space vehicles. The system is led by NASA's subsidiary, the Marshall Space Center, and is fully known as the Heliopause Electrostatic Rapid Transit System, also known as the Solar Electric Sail Propulsion System HERTS. Is it particularly futuristic to look at the appearance alone? Has it overturned your understanding of aircraft?

Structural composition of electronic sails

The electronic sail is not as complete as the traditional sail surface, and as the main part of the propulsion system, there are some particularly slender aluminum wires. Yes, you're not mistaken. Those slender wires are aluminum wires. Of course, this is not a common aluminum wire in our daily lives. These aluminum wires are extremely thin and long, with a diameter of 1 millimeter, roughly the same thickness as a paper clip, and they are super long, measuring 12.5 miles, or about 20 kilometers. What is the concept of this length? It is almost the length of 219 football fields arranged together. An electronic sail typically consists of 10-20 aluminum wires radiating from the center to the surroundings. After the rocket reaches the designated position, the aluminum wire is extended from the center to both ends, and two small rockets are used to propel and complete the fan-shaped deployment task of the aluminum wire group. Complete the final deployment form of the electronic sail.

The Power Source of Electronic Sails

Of course, having such an electronic sail propulsion system is not enough to set sail in space. The important aspect of interstellar navigation is propulsion power. Traditional aerospace engines require their own propellants, which account for a large proportion of the total mass of rockets and seriously constrain the payload and flight distance of spacecraft. Therefore, seeking more effective ways to advance has always been the direction of scientific research.

Scientists have turned their attention to the sun, the ultimate energy boss in the solar system. Electronic sails are propelled by the solar wind generated by the sun. Unlike the wind composed of molecules on Earth, solar wind is a stream of supersonic plasma charged particles emitted from the upper atmosphere of the sun, composed of particles such as protons and electrons, and the effects they produce when flowing are very similar to air flow. The density of the solar wind is very thin and insignificant. Generally, in the interplanetary space near Earth, there are several to dozens of particles per cubic centimeter, while the density of the wind on Earth is 268.7 billion molecules per cubic centimeter. However, the strong force of the solar wind is far stronger than the wind on Earth. The speed of the solar wind near the Earth is generally 350-450 kilometers per second, and can reach 800 kilometers per second when strong. It may not feel much just looking at the numbers. You should know that the strongest winds on Earth are typhoons, with wind speeds of only 32.5 meters per second or above for Category 12 typhoons. Such wind speeds are already a disaster.

Due to the thinness of the solar wind, we have no intuitive perception of it. But its ultra-high speed is the key to the black technology of electronic sails. In fact, some scientists have previously attempted to use the solar wind for interstellar flight. NASA successfully launched a small solar sail powered satellite in 2010. In May of the same year, a space probe named IKAROS from the Japanese Space Agency was launched, proving the possibility of using solar sails for interstellar navigation. Unlike previous solar sails that used extremely thin metal plates with sail effects and relied on solar pressure for propulsion, this electronic sail project used the aluminum wires mentioned above. These aluminum wires will be positively charged, utilizing the force of repulsion with particles in the solar wind to provide power for spacecraft and spacecraft. In theory, it does not require any propellant, as long as there is sunlight, it can fly, and its flight speed is much faster than existing aircraft, with an expected high speed of 400 to 750 kilometers per second.

The high-speed movement of electronic sails

In order to better understand electronic sails, a new unit needs to be introduced. In astronomy, the astronomical unit AU is commonly used to represent distance, rather than the length unit we commonly use. An AU refers to the average distance from the sun to the Earth, approximately 149.6 million kilometers. Due to the thinning of the solar wind as it moves further away from the sun, in order to ensure sufficient thrust and acceleration, the effective area of the electronic sail will increase with the range. At 1AU, the effective area is 601 square kilometers, which is only slightly smaller than the downtown area of Chicago; At 5AU, the effective area can reach 1200 square kilometers, which is close to the size of Los Angeles.

Another advantage of electronic sails is that their acceleration distance far exceeds that of solar sails. Generally, if the range of a solar sail exceeds 5AU, its acceleration will stop due to the dissipation of solar photon energy. Due to the continuous particle flow and increased effective area, the acceleration of the electronic sail will not stop, but will continue to a distance of 16-20AU. As the first human spacecraft to reach the edge of the solar system, Voyager completed its mission in 2010 after 35 years of flight. However, electronic sails can complete this task in 12 years or even less. So, this black technology may overturn existing propulsion technologies.

Of course, this technology has not entered the launch phase, and the number of protons repelled by the wires and the number of electrons attracted by the wires are still being tested at the Marshall Space Flight Center. Plasma testing is also underway to correct the model. It is expected that within 10 years, electronic sails will officially debut on the aerospace stage. In fact, regardless of the future of electronic sails, there will inevitably be explosive technological breakthroughs in human space that will overturn existing technologies, and our footsteps in space will also become increasingly distant. Only breakthrough ideas can bring about breakthrough technology.