XR2 RAVENSTAR VC (WIP) - Singapore to London - Testing SCRAM ascent and runway landing autopilots. 

Agreed, I will definitely add the ability to directly type the base's name or even the coordinates.

Hi David, I pinned a comment describing how the flight goes from the user's perspective. Is short, the scram ascent AP takes you towards the target, you take over after MECO at 75 km altitude to make sure that AerobrakeMFD will get you to ~50 km away from the target and slightly earlier than that (100 km from the target) the landing script takes over and lands you on the runway.

Hi @glados1073, thanks for the link. I agree with you that it would be pointless to raise a question on a 9 year old video. As your intuition and experience in Orbiter have already shown you, he is not right about Orbiter using strictly 2 body Keplerian calculation to propagate the state vectors of a vessel in the simulation. The 2-body method is only used as a baseline for further calculations. My source is the dynamics.pdf that is located in the Doc\Technotes folder of your Orbiter installation. If you're so inclined, it is an interesting read. Orbiter takes into account the gravitational influences of multiple celestial bodies when propagating the state vectors of a vessel. While the pdf describes the use of a "2-body orbit" as a baseline for certain calculations, it explicitly mentions the inclusion of gravitational potentials from relevant celestial bodies. Here's a more detailed explanation according to the content of the dynamics.pdf written by Orbiter's creator Dr. Martin Schweiger: Gravitational Forces: The gravitational acceleration 𝑔(𝑟,𝑡) at any position 𝑟 and time 𝑡 between 𝑡0 and 𝑡1 is computed, which involves the summation of numerically calculated gravitational potentials from relevant celestial bodies. This indicates that the gravitational influence of multiple bodies is considered. Perturbations: In cases where time intervals become too large for accurate numerical integration of state vectors, Orbiter switches to "orbit stabilisation," a variant of Encke’s method. In this method, only the perturbations on top of a baseline 2-body orbit (defined by its osculating elements) are integrated numerically. This further suggests that while a 2-body model may serve as a baseline, additional gravitational perturbations from other bodies are incorporated. Numerical Methods: Different numerical integration methods, such as Runge-Kutta and symplectic integrators, are used to solve the equations of motion, which include gravitational forces from multiple sources. For example, in the symplectic integrators section, the methods are noted for their stability in long-term integration, which is crucial for accurately modeling the effects of multiple gravitational influences over time. Simulations: The numerical simulations section mentions that the gravitational point sources (Sun, Earth, Moon) were considered in the computational cost analysis of time propagation methods. This clearly indicates that multiple gravitational sources are factored into the simulations. Therefore, Orbiter does not rely solely on 2-body calculations; it accounts for the gravitational influences of other celestial bodies in its state vector propagation. Hope this answers your question. Best regards, Dimitris

@@dgatsoulis By the Gods this was a lightning fast response! Thank you, it indeed answered my question, now i have something interesting to go read (even though i'm not sure how much i will understand from it) AND most importantly i know i'm not crazy heheh.