In the early 1980's NASA Johnson Spacecraft Center (JSC) was faced with upcoming space tether experiments to be flown aboard the Shuttle. Such flights would have to pass preflight control system and safety certifications. The author of GTOSS was approached by JSC to provide the means to perform these certifications in the context of JSC's existing Orbiter engineering simulations. From this effort was born the GTOSS tether analysis capability, a by-product of the author's software design (which had provided the necessary tether capability for JSC's existing simulations). This development occurred under the administration of the (then) Avionics Systems Division, Johnson Space Center.
The GTOSS software system consists of over 500 subroutines representing 60,000 lines of code, with 15 volumes of documentation (over 800 pages) describing user operation, mathematical model derivations, and system software design. A total of about 160 megabytes of code and support data constitutes a delivery of the GTOSS CD ROM. GTOSS programming is characterized by top down design, object oriented structure, modular isolation of environment effects simulation, and convenient software hooks provided for user modification. The code is constrained to a highly portable subset of Fortran 77, and runs on all mainframe computers as well as PC's such as Macintosh and Windows OS. Automated verifying of code modification is provided.
GTOSS is a tether analysis-complex best described by addressing its family of modules, which are more or less tightly associated as a cooperative whole.
The GTOSS COMPLEX consists of the following application modules:
GTOSS Generalized Tethered Object Simulation System
TOSS Tethered Object Simulation Sub-system
RTOSS Results Data Base (RDB) sub-system
BTOSS Boom (ie Flexible tether boom) sub-system
DTOSS Data-printout system (an RDB post-processor)
CTOSS Column-delimited-graphics system (an RDB post-processor)
STOSS Super 3-D Dynamics Animation system (an RDB post-processor)
UTOSS Universal Data Export/Import system (an RDB post-processor)
VTOSS Verification system for automated verification of TOSS
See GTOSS Features and Learn More about GTOSS in the Executive Overview
The current version H.9 of GTOSS is available on CD ROM