What would a person use to model a structure in microgravity (more specifically, in free fall) like a space station or a space habitat like those proposed by Gerard K. O'Neill and the Space Studies Institute in a 3D software package?
I have a fair amount of experience using Blender, Maya, and 3DS Max, three of the most popular 3D programs, and all allow you to set gravity to any value, including zero, for physics simulations. I believe that most of the Autodesk/AutoCAD software allows you the same freedom, though I can't speak from experience there.
However, a vast majority of 3D modeling doesn't require gravitational calculations to begin with, and these forces only become relevant when you turn physics simulations on. Unless you are specifically interested in computing object collisions, you don't need to worry about what gravity is set to.
Most 3D modelling packages let you define forces - I wasn't aware Blender had gravity turned on by default, but you can turn it off.
Generally though, modelling is unlikely to require it unless you are doing detailed stress analysis, in which case I'm not sure Blender would be up to the job.
3D Modeling Programs:
- SolidWorks - Used almost universally for quick spacecraft design and development. Commonly used for SmallSat/CubeSat development, however for higher fidelity design it's common practice to use Siemens NX due to the wide verity of modeling tools and how the software can handle large complex spacecrafts.
- Siemens NX - Commonly used throughout the aerospace/space industry (NASA, SpaceX, and various other companies). Excellent software for development of large complex systems. Has a large tool and application set to make engineering, management, development, manufacturing, and analysis easier.
- Catia - Another commonly used software within the industry. Used by Boeing, Northrop Grumman, and Bombardier. Used for both spacecraft and aircraft development.
- Creo - Not as commonly used as the others, but still a great software that can aid in the development of spacecraft and aircraft systems.
Software Simulation & Analysis Programs:
COMSOL Multiphysics - Great simulation package for complex analysis and simulation of spacecraft systems in various environments.
Thermal Desktop - Ideal and commonly used across various NASA facilities for thermal analysis related work.
Integrated CAD Simulation Tools - There are various simulation packages integrated into SolidWorks, NX, Catia, and Crea. Some packages may be idea for certain scenarios, while others might be limited in their ability to handle complex simulation scenarios.
Proprietary Software - Complex software such as Monte developed by NASA is a large complex "state-of-the-art aerodynamics" Python library that is commonly used to analyze mission trajectories and attitude maneuvers.
Orbital Trajectory Software Simulation & Analysis Programs:
AGI STK - Wide spread and accepted trajectory and mission design software.
GMAT - Developed by NASA for trajectory and mission design. NASA uses both STK, GMAT, and Monte, just depends on the type of mission and what the engineer prefers.
FreeFlyer - Not very commonly used.
JAT - Open source simulation package developed on the JAVA framework.
Poliastro - Open source pure python package dedicated to problems arising in astrodynamics and orbital mechanics.
3ds Max, Maya, Blender, or Cinema4D are great softwares for quick concept design and is commonly used in the game/entertainment industry. However, they are severely limited in terms of functionality for engineering related design work and analysis, and therefore are not used in spacecraft development .
Source: Spacecraft systems engineer and either heard or used these tools.