Surveyor spacecraft addon for Orbiter

An Orbiter addon that demonstrates the Surveyor lunar probe with a functioning landing autopilot

Building and running

Download/Install Orbiter from http://orbit.medphys.ucl.ac.uk/
Install Visual Studio 2019
Install Rust using rustup (https://rustup.rs)
Install the win32 target by running rustup target add i686-pc-windows-msvc
Build the project by running cargo build in the project root
Copy the target/i686-pc-windows-msvc/debug/Surveyor.dll to the <OrbiterPath>/Modules
Copy the files under the Scenarios, Meshes and Textures folders into the corresponding folders in the Orbiter install directory
Open Orbiter and run the "SurveyorTerminalDescent" scenario

The descent guidance in this addon is implemented based on the descriptions in the following papers/reports:

Surveyor Mission Report - Part 1, Page 60
Surveyor III Mission Report - Part 1, Page 40
Surveyor Spacecraft Automatic Landing System by Sam W, Thurman
Design Considerations for Surveyor Guidance by R.K. Cheng, C.M. Meredith, and D.A. Conrad
Surveyor Terminal Guidance by R.K. Cheng

The "descent contour" was approximated from the plots in the above reports.

Big thanks to Harish Saranathan for clearing up some of my questions about attitude control. He has made his own version of the Surveyor descent guidance algorithm in C++ which can be found here: https://github.com/harishsaranathan/SurveyorAutopilotForOrbiterSpaceFlightSimulator.