Simulation
Simulation and Engineering Software
Physics Models
Imagine you built a simulator so that when you added weight to the climber, the ribbon dimensions got bigger. If a spreadsheet created calculations that boiled down to simple algebraic formulas, those could be put into a video game.If someone improves the spreadsheet, they can swap in a different algebraic constant.
There is also Finite Element Analysis software: http://en.wikipedia.org/wiki/List_of_finite_element_software_packages
Dynamics, basic principles relationships, materials properties,...
Codebase_Analysis#Physics_Engines
Spreadsheets
Ribbon dimensions, performance trade-offs, overall interactions matrix.
3-D Design Files
Sketchup, Cinema 4-D, others
Blender
Complete tutorial: http://www.cdschools.org/54223045235521/lib/54223045235521/BlenderBasics2.42a.pdf
http://www.blender.org/education-help/tutorials/tutorial-folder/blender-user-interface-tutorial/
http://www.blender.org/education-help/tutorials/#c836
http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro
Other Software
NASA's free code: http://opensource.arc.nasa.gov/