By cable to Earth orbit… What is the Skyhook idea?

Rather than rocket technology that consumes huge amounts of fuel and can only bring goods into space, orbit elevator technology has been proposed to build an elevator that extends from ground to geostationary orbit. In the midst of this, the Skyhook plan, which connects cables above the sky and allows them to step into space at a lower cost than an orbital elevator, draws attention.

According to YouTube channel Kurzgesagt, going to space with the current technology is like climbing on a unicycle with a backpack of fireworks. This is because rockets have to achieve speeds of up to 40,000 km/h while burning large amounts of fuel to defeat Earth’s gravity, creating enormous costs and risk of accidents. Moreover, even if it is difficult to launch a rocket, there is not much weight that can actually be sent into space. For this reason, the concept that emerged is Skyhook.

Skyhook is based on the idea of building infrastructure that supports not only bridges, ports, railroads, and ropeways, but also the way to space. A similar idea is a track elevator that connects from the ground to more than a geostationary orbit. However, unlike an orbital elevator, Skyhook does not require enormous initial investment or magical new technology.

Skyhook is a type of rope propellant that will connect the spacecraft to strong ropes for a long time or modify its track. The concept of Skyhook is simple and all you have to do is launch the cable onto the track. The basic principle of Skyhook is that if a spacecraft is connected to the end of a cable that is hundreds of kilometers to thousands of kilometers long, the cable is used to transport the spacecraft to the other side and quickly send it into space.

There is also an improvement plan that uses one end of the cable as a counterweight and rotates the entire rope round and round. As the rope rotates, it orbits the earth and throws a rocket into space. The rope must be able to withstand cosmic debris or meteorite impact, but it is said that it can be sufficiently realized by twisting existing synthetic fibers that have twice the strength of body armor and boast high elastic modulus and flame retardancy.

Since the end of the rope descends from 80 km to 150 km above the ground, the spacecraft can reach space without breaking through the atmosphere. Therefore, the cost required is much less than going to space on a rocket alone.

Of course, connecting ropes and spacecraft flying at 12,000 km/h must be handled with automatic navigation systems and unmanned aerial vehicles as humans cannot. There is also a problem that the rope gradually loses its rotational energy while sending the spacecraft, but this can bring the spacecraft back from space back to the ground by recoil. In other words, the rope acts like a kind of battery that stores the energy that the spacecraft travels back and forth.

Even if the track is off, it can be corrected with an electric propulsion or propellant engine. The idea of regularly picking up spacecraft and maintaining its rotation could also provide regular flights between Earth and Mars. This makes it possible to get to Mars much cheaper than rocket traffic. In addition to simply fuel problems, sailing between Earth and Mars, which would take nine months, can be shortened to three months, and rockets can be downsized by 84-96%. In addition, using this method, the resources obtained through the asteroid can be sent to Mars to help pioneer.

It is also possible to create a large-scale rope using Mars’ satellite Phobos to create a platform to advance to Jupiter. It can be said that it is a theoretically possible dream to connect the planets of the solar system from next to the next by continuing this network.