GTOSS Simulation of the Space Elevator
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.
GTOSS addresses most of the unique space elevator dynamics attributes. An enumeration of these challenges and how GTOSS addresses them is found at Space Elevator Dynamic Challenges.
You can learn more about GTOSS's general and detailed attributes at the GTOSS description web site.
Those interested in working with GTOSS please contact David Lang. The GTOSS program is being made available to individuals with the background knowledge to use it. The code is large and extremely complex as are the engineering input parameters and interpretation of the output results.
The GTOSS source code is made available via a source sharing facility http://sharesource.org 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 (for instance, "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 User Guides and Reference Manuals are located here: http://keithcu.com/GTOSS%20Reference%20Docs.zip
Ribbon Dynamics Simulation
The space elevator is a challenging dynamics problem, characterized by:
- A topology that spans a significant portion of a gravity-well,
- A Unique aspect ratio,
- A perturbing environment that includes; wind, passing gravity wells, solar wind pressure, solar heating, ascending climbers and a moving anchor.
An extensive study was undertaken by David Lang using GTOSS to simulate space elevator dynamics from deployment through operation. These studies have resulted in Papers, a Space Elevator Dynamics Handbook, and numerous illustrative engineering animations of GTOSS simulated dynamic behaviors.
Some results of those studies are shown below.
Space Elevator Dynamics Handbook
This handbook covers many of the dynamic attributes and responses of the space elevator (note: in addition, the papers listed in the next section also expand upon and extend the contents of the handbook).
The complete handbook is a 150 page, 10.2 MB, PDF document; In addition, it has been sub-dividied for ease of download and access for those so preferring.
Sec 1: File:Dyn HB Sec 1.pdf Basic Elevator Dynamics Facts, Physical Attributes, Useful Formulas, etc.
Sec 2: File:Dyn HB Sec 2.pdf General Dynamic Behavior.
Sec 3 & 4: File:Dyn HB Sec 3+4.pdf Debris Avoidance (not finished); Aerodynamic Response.
Sec 5, 6 & 7: File:Dyn HB Sec 5+6+7.pdf Climber Dynamics; Construction; Failure Modes.
Sec X: File:Dyn HB Appendix.pdf Appendices and references.
Dynamics Handbook as a Single Download for those who want to download the entire handbook in one operation, rather than by sub-sections (per above) File:Dyn HB Final pdf.pdf:
Papers and Related Explanatory Animations
Note: Following each paper below is a link to a page that presents animations of GTOSS simulations specifically related each paper's subject; these animations will clarify, supplement and expand upon the contents of each paper.
Paper on Aerodynamic Response to Atmospheric Wind (PDF)
See animations pertaining to Aerodynamic Response
Paper on Dynamic Response to Climber Transits (PDF)
See animations pertaining to Climber Dynamics Response
Paper on GEO-Based Construction Deployment Dynamics (PDF)
See animations pertaining to Construction Deployment
Selected GTOSS Simulation Animations
Wave Propagation Animations
Many aspects of the propagation of transverse (ie horizontal) waves along the space elevator ribbon are presented here