FreeFlyer User Forum

I’m new to FreeFlyer and looking to learn how to model a trajectory from Gateway to the lunar surface. I recently watched a short video of an HLS spacecraft landing but didn’t see a walkthrough or tutorial on modeling the process.

I’d like to build on the existing NRHO model that FreeFlyer has already developed and optimize the time and delta-V required to land an HLS system on the Moon from Gateway. Does anyone have tips, tricks, or recommendations on where to start? Any resources you’d suggest for getting up to speed on this?

FreeFlyer’s current optimization capability can be used for multi-variable optimization of a user-defined objective function. However, the problem you are describing is a multi-objective problem; optimizing a trajectory with multiple objective functions (i.e. minimizing both time and delta-v). Solving multi-objective problems will be much easier in FreeFlyer 7.10 with the new Multi-Objective Optimization feature! When FreeFlyer 7.10 is released, we will provide a guide on this topic in our Help File and several Sample Mission Plans demonstrating this feature.

In the meantime, I recommend you review our guide on Optimization in our Help File. To address your other questions, you can set the spacecraft’s central body in FreeFlyer script using the Spacecraft.SetCentralBody() Method and review our Help File page on Object Central Bodies. You can also propagate Gateway using the ephemeris provided with your installation of FreeFlyer located here: FreeFlyer 7.9.1.11316767 (64-Bit)\Sample Mission Plans\_Support_Files\gateway_eph.FFEphem