Lofstrom Loop
Lofstrom Loop
Image from Steve Bowers
This Lofstrom Loop was the first ever raised above the Earth, at the start of the Great Expulsion

Dynamic launch loop using a continuous stream of linked magnetic units to raise payloads above the atmosphere for launch.

The stream is sent into space, typically about 80km up. At the top the loop runs horizontally for 2000km, allowing payloads to be accelerated to orbital speed. The continuous stream of metal links then descends to the ground, where it is reversed by a large, loopshaped accelerator. The stream is then sent back aloft and repeats its journey to the original ground station.

Vertical elevators raise payloads to the westernmost end, to start their acceleration to orbital speed; the loop is only used for launches, as aerobraking is generally used for descending traffic on worlds wherever Lofstrom Loops are used.

This structure contains a large amount of kinetic energy but, because it is only raised gradually, only requires enough energy to compensate for losses when finished.

The first Loop was built by GAIA during the Great Expulsion, the first of many built at that time to assist in the mammoth task of evacuating Earth. Many medium tech worlds use these loops wherever full-scale space elevators are not available; another system used in similar circumstances is the Rotovator.

[after Keith Lofstrom, who set forth the first detailed calculations on this system, late Atomic/early Information period].

Lofstrom loops
Image from Operapoints
One of the Lofstrom loops created by GAIA to help in the Great Explusion
Related Articles
  • Lorrey Loop - Text by Steve Bowers
    Advanced form of Lofstrom Loop using three geostationary terminii in orbit at the points of an equilateral triangle, and three ground terminii opposite them, connected by a stream of vessels or particles which travel in Hofmann orbits (except when in the atmosphere), thereby saving energy.
  • Rotovator
  • Skywheel
  • Space Runways
Appears in Topics
Development Notes
Text by Anders Sandberg in his Transhuman Terminology
Initially published on 03 December 2001.

image by operapoints added november 3, 2023
expanded from 1 paragraph, january 2009, steve bowers
Additional Information
Isaac Arthur's YouTube Channel:
Launch Loops

The Launch Loop - Keith Lofstrom