Simplify the single-stage-to-orbit (ssto) example ODE.

[robfalck]

Summary of Issue

Simplify the SSTO example ODE to make it more digestible for new users.

Issue Type

• Bug
• Enhancement
• Docs
• Miscellaneous

Description

The SSTO case uses an ODE which is composed of two components. To make dymos easier for new users, we should use complex-step differentiation in more of our examples. For the SSTO case, the ODE should become a component (rather than a group) that includes both the atmosphere model and the 3DOF vehicle dynamics. It should use complex-step differentiation with partial coloring to make the differentiation as efficient as possible.

Performance comparisons with the analytic differentiation version should be done to see whether this is a good strategy for dymos ODEs in general.

Example

N/A

Environment

dymos 0.18.1-dev