OpenSpace 5

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Space Catapult

Author: Mr. Giorgi Lobzhanidze

Address: Tbilisi, Republic of Georgia, Europe

Email: mailto:giorgi9@gmail.com

The new method for sending the spacecrafts in deep space is presented here. The paper describes the long rod rotated by electro motor placed at the Space Elevator’s counterweight and at Lagrangian points. This simple structure will enable the rod to gain high velocity and carry the payload with it. After reaching the desired speed the rod will release the payload that will fly in space along the imaginary circle’s tangent. This structure we called Space Catapult and it should work with the assist of Space Elevator. This latter should be used for carrying the payload from the Earth to Space Catapult’s rod.

For exploring the outer space the humankind generally uses the rocket engines, mostly chemical-propelled ones. They enable us the explore near-Earth celestial bodies and other planets in the solar system. They even enabled us to send several deep space missions beyond the solar system such as Pioneer-10, Pioneer-11, Voyager-1, Voyager-2, however by means of this technology the flight lasts undesirably long and it seems to be impossible to reach remote celestial bodies in space such as stars, so new technologies are necessary for this purpose. However new technologies do not necessary imply new kind of rocket engines, such as Ion Drives because they are capable for gaining several ten times higher speeds only, but for remote celestial bodies even they are not suitable. Besides, they need a huge amount of energy to be stored onboard the spacecraft and this will make additional problems. So, high speed should be achieved with absolutely different approach. How this can be done?

High speed can be easily achieved by means of fast-rotating rod around the electric motor. The motor’s rotational speed can be very high; the rod also can be quite long, hence the rod’s end’s linear speed can be extremely high, absolutely unachievable for any other technologies nowadays. The payload should be fastened at the rod’s end where the linear speed generally reaches maximal value. After reaching the necessary speed the rod will release the payload that will fly along the tangent from the current position. Thus the electric energy can be turned into payload’s speed and its velocity could be as high as we wish (except the speed of light of course). In principle the Space Catapult (thus we call this structure) would be the simplest, the most convenient and direct way for converting the energy/electricity into speed and conveying it to payload.

As we see the Space Catapult is quite uncomplicated structure, however if we wish to gain high speeds we should deploy it in space, not on the Earth. Indeed, our planet is surrounded with dense atmosphere that impedes any quick motion, so if we rotate the rod quickly the atmospheric drag and generated heat would burn it very soon, therefore the Space Catapult should be built and deployed in space only, and as we suppose-at the Space Elevator’s counterweight. In other words, the Space Elevator’s counterweight will operate as Space Catapult. See image below: Generally, what is the Space Elevator ^{1 2}? According to modern concepts it will be the tall vertical structure built on equator and will have height of several ten thousand kilometers with its thin cable fastened to the base station on the Earth and with counterweight placed higher geostationary orbit. Because of balance between centrifugal force and gravity this structure will be stretched and the cabin will move along its cable carrying the goods into high orbit. After delivering the payload, the cabin will descend and carry the next one. In Space Elevator’s concepts several solutions have been proposed to act as a counterweight:

1. Heavy, captured asteroid

2. Space dock, space station or spaceport positioned past geostationary orbit

3. Extension of the cable itself far beyond geostationary orbit.

The third idea has gained more support in recent years due to the relative simplicity of the task and the fact that a payload that went to the end of the counterweight-cable would acquire considerable velocity relative to the Earth, allowing it to be launched into interplanetary space. However this idea cannot be completely shared by us due to following reason:

It is well-known that the values of both Orbital and Escape Velocities decreases with increasing the altitude while the tangential velocity of Space Elevator’s cable increases. We can see the differences between them from the chart presented below: