Alexander Bolonkin

Dr. Alexander A. Bolonkin is a Russian-born (1933) scientist who moved to the United States in 1988. Numerous articles and patents.

In his book Non-Rocket Space Launch and Flight (Elsevier 2006). This is mostly a rewritten version of many conference papers. Dr. Bolonkin discusses many megastructure alternatives for space launch, from the space elevator to dynamic structures to gas guns to electrostatic devices. Dr. Bolonkin presents many ideas, with some analysis, and focuses on what might work, not on what might go wrong, avoiding the sort of analysis engineers do before deployment (it is cheaper to break stuff and find fixes with math before cutting metal, especially for megastructures).

Launch Loop uses magnetic fields and vacuum confinement. Non-Rocket... has two chapters on Kinetic Space Towers (Chapter 5, IAC-02-IAA.1.3.03 2002, JBIS 57 1/2, 2004, pp 33-39) and on Kinetic Anti-gravitator (Chapter 9, IAC-02-IAA.1.3.03 2002, AIAA-2005-4504). These are open, vertical systems, and use outer rollers for turnarounds. Dr. Bolonkin does not discuss how these rollers are made, or how a roller can rotate with high edge speed without flying apart. The launch loop elevators include tapered high-velocity pulley rollers moving at 400 meters per second, and this is probably too optimistic.

Dr. Bolonkin may be unaware of the effects of gravity on vertically moving cable velocity. The launch loop cable is moving at 14000 meters per second at 80 kilometers altitude. As it descends towards the surface, it picks up speed, adding an additional 9.7 x 80000 Joules per kilogram, raising the speed of the cable to 14055 meters per second. Since the mass flow rate is constant at 42000 kilograms per second throughout the system, this means that the density of 3 kilograms per meter at 80 kilometers altitude must be reduced to 2.988 kg/m at the surface - a 0.4 percent stretch. Payload launching results in both stretching and compression, again because of velocity changes.

Dr. Bolonkin's towers are similar heights (75km) and run at lower velocities ( 8000 m/s ) so the stretching must be larger. If the velocity is 8000 m/s at the top, the velocity at the bottom must be 8090 m/s, a stretch of 1.1 percent. If the cable is solid and made of a strong material, that stretch is associated with tensile stress at the bottom, which adds to the compression burden on the tower. If there is no tension at the bottom, then the cable at the top will meander, like a rope pushed from both ends.

This is why the launch loop rotor (like Bolonkin's cable ) has sliding joints, which resist lateral bending but otherwise offer only slight resistance to longitudinal stress, allowing the rotor to change longitudinal density. Most of the material in the rotor is iron, perhaps with some insulation ot direct eddy currents. A solid iron rotor, and most insulator materials, will fracture if subjected to strains approaching a percent.

On page 184 of Non-Rocket..., Dr. Bolonkin briefly mentions the launch loop, quoted below:


In 2002 Loftstrom4 published a description of a space launcher. The offered device has the following technical and physical differences from the Loftstrom installation.

The Loftstrom installation has a 2000-km long launch path located at an altitude of 80 km, which accelerates the space vehicle to space speed. The Loftstrom space launcher is non-connected plates of complex path enclosed in an immobile tube. The plates are made from rubber-iron material and is moved using an electromagnetic linear engine. The plates are turned by electromagnets.

The idea offered in this chapter is the kinetic device which creates a push (repulsive, repel) force between two given bodies (for example, between a planet and the apparatus). This force supports a body at a given altitude. The body is connected to the cable by rollers that slide along the cable. The cable can be made of artificial fiber and moved by the rollers and any engine. The kinetic anti-gravitator supports any body at altitude (for example, towers) and may also be used to launch vehicles. The Loftstrom device is only a space launcher and cannot permanently support a body at altitude or towers (he did not write anything about this).

4. K.H. Lofstrom, "The Launch Loop: A Low Cost Earth-to-High-Orbit Launch System", 2002, http://www.Launchloop.com/launchloop.pdf