TST: 2-stage Acceptance Test

[chasgior214]

Is your feature request related to a problem? Please describe.

With RocketPy getting more into multi-stage rockets, an acceptance test to verify the reliability of multi-stage simulations would be a good next step.

Describe the solution you'd like

NASA has published a series of verification check-cases for atmospheric flight, available at https://nescacademy.nasa.gov/flightsim

Check-case 17, Two-stage rocket to orbit, would be a great addition to RocketPy's tests, and its first test case for a multi-stage rocket. While the initial implementation doesn't have to test against the whole flight, it could give verification to RocketPy's ability to simulate multi-stage rockets in the lower layers of the atmosphere, and in the future provide a way to verify orbital simulations (#277).

Additional context

As noted in the abstract of the linked webpage:

The rise of innovative unmanned aeronautical systems and the emergence of commercial space activities have resulted in a number of relatively new aerospace organizations that are designing innovative systems and solutions. These organizations use a variety of commercial off-the-shelf and in-house-developed simulation and analysis tools including 6-degree-of-freedom (6-DOF) flight simulation tools. The increased affordability of computing capability has made high-fidelity flight simulation practical for all participants. Verification of the tools' equations-of-motion and environment models (e.g., atmosphere, gravitation, and geodesy) is desirable to assure accuracy of results. However, aside from simple textbook examples, minimal verification data exists in open literature for 6-DOF flight simulation problems.

Adding these to RocketPy (with the two-stage rocket as the first step) would help bring it closer to industry-grade robustness and accuracy.

[Gui-FernandesBR]

Related issue: #45

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@chasgior214 thank you so much for opening this issue. We were planning to improve the multi-stage support on rocketpy this year but we faced a few delays and decided to prioritized other implementations. Your suggested links may help us once we decide to get back to work on this feature, thx

[Gui-FernandesBR]

Related: #662 and #45