GTOSS is a tether simulation code developed by David Lang to study the dynamics of a wide variety of tethered object configurations, both terrestrial and in space. This code was first used for flight certification of the Shuttle TSS experiments, and is capable of simulating many aspects of the space elevator system dynamics. The source has been made freely available to those interested and capable of pursuing similar studies. You can learn more about GTOSS's general attributes at the GTOSS description web site.
DOWNLOAD The code is made available via a source sharing facility "sharesource.com" and is based on the Mercurial source management software system; Make sure you have Mercurial and relevant fortran compilers, etc. installed. Using a Unix or Linux type shell-terminal interface (say "Terminal" on Mac OSX or Ubuntu, etc),
hg clone http://hg.sharesource.org/gtoss
Note: Inside the "SE Dynamics Exploration Runs" directory there are 35 GTOSS input-run streams that produce a wide variety of space elevator analyses.
Getting started documentation is here: File:Getting Started with GTOSS.pdf
Full Docs are located here: http://keithcu.com/GTOSS%20Reference%20Docs.zip
The space elevator is a challenging dynamics problem. It reaches through a gravity well, has a very unique aspect ratio, is in an environment with wind, passing gravity wells, solar wind pressure, ascending climbers and a moving anchor. An extensive study was undertaken by David Lang to simulate the system from deployment through operation. Some results of those studies are shown below.
|GENERAL GTOSS SIMULATION RESULTS
File:Dyn HB Final pdf.pdf: Large compilation of David Lang's Space Elevator dynamics work. (10.2Meg PDF) - This document will be split and referenced.
SELECTED ATMOSPHERIC WIND RESPONSE ANIMATIONS (Deflection distances are generally magnified & time is accelerated)
Note, these winds are very high, and are not typical of the space elevator geographical location
File:Lang Movie Low.avi: AVI movie: Stop-time animation with Low altitude view and atmospheric density depiction
File:Lang Movie Full.avi: AVI movie: Stop-time animation of entire elevator length (with horizontal response scale greatly magnified)
SELECTED WAVE PROPAGATION ANIMATIONS VIEWED AT RIBBON HIGH ABOVE EARTH (Deflection distances are generally magnified & time is accelerated)
Note: this wave originates at the ground in response to a planned base-movement
: QUICKTIME movie, Horizontal scale is greatly magnified
Note: the above QT movie was made using the application SpaceAnimator, created by Paul Snow
(you can contact Paul in the Seattle area at "firstname.lastname@example.org", phone: 425 466-1405)
PAPERS AND RELATED EXPLANATORY ANIMATIONS
File:Paper Lang Aero.pdf: Paper on Aerodynamic Response to Atmospheric Wind (PDF)
File:Paper Lang Climber Transit.pdf: Paper on Dynamic Response to Climber Transits (PDF)
File:Paper Lang GEO Deploy.pdf: Paper on the Dynamics of GEO-Based Construction Deployment (PDF)
For those interested in working with GTOSS please contact Brad Edwards at email@example.com. The GTOSS program is being added to this site and will be made available to individuals with the background knowledge to use it. The code is extremely complex as are the input parameters and interpretation of the output results.