Space elevators.

Space elevators are futuristic launching structures that are used to drive satellites or other spacecraft to the orbital trajectory. The space elevator is a tower that rises to the orbiter. The problem with that kind of structure is its weight is enormous. The solution is that there is a counterweight. That pulls the tower outward. And that thing denies the space elevator collapse. 

Another version is to use pressurized air to keep the space tower in its form. Researchers planned to build a space elevator on the equator, and then the centripetal force can throw the satellite into space. The space elevator is meant to use as the system that shoots small satellites into the orbiter. So the space elevator is not meant to send spacecraft to other planets. 

But there is another type of plan for that futuristic system. The first version is that the space elevator is the nanotechnical wire that is made between the satellite and the ground. The wire would be equipped with a magnetic track. And that kind of system can also transfer donut-shaped satellites to the orbiter. The larger satellite will connect to the miniature satellite with strong wires. And then the magnetic track. Along with the physical wires will rise miniature satellites to the orbiter. 

In some visions, the space elevator is not built on Earth. The idea is that miniature satellites are made on the Moon in robot factories. Then the space elevators are pushing them to the Earth orbiter. Gravitation on the moon is far lighter than on Earth. So there the space elevator could work, but the system must use some other way to make the acceleration than the centripetal force. 

In some visions, the lunar-based launching systems use the sling. The satellite will connect to the wire that throws it to Earth. These kinds of systems don't require very much energy, because of weak gravitation on the Moon. Kinetic energy use denies the effect of magnetic fields in launching systems. 

The space sling can also install in satellites or airships. In some visions, the stratospheric balloon or airship can be equipped with a sling that shoots a small about 2kg. satellite to orbiter without a rocket engine. Or the orbiting satellite can use a space sling to send small probes to research things like comets and asteroids.