I recommend creating a relative motion ("LVLH" - Local Vertical/Local Horizontal and sometimes called "LVC" for "Local Vertical Curvilinear") plot for use when planning and performing orbital rendezvous. I recognize this is probably more of a long-term suggestion for the game, but I wanted to suggest it nonetheless. Short explanation is that this is the frame of reference used in mission design and executions in real space rendezvous, and it allows for a much more intuitive and efficient rendezvous than the simple "intercept-and-null" that a KSP-style planet-centric map allows for. It's particularly valuable for late-game gameplay that might consist of building space stations or assembling large multi-segment ships for missions deep into the solar system. The actual math to implement this sort of plot view is remarkably simple, using just the inertial state vector of the two spacecraft.
Here's the longer explanation, starting with a great article from a former NASA FDO (Flight Dynamics Officer), and an example plot:
The frame shows the relative motion between two spacecraft in orbit, the Target and the Chaser. This plot is in the plane of the Target's orbit - a second plot shows the planar offset of the two spacecraft. The Target is always located at the origin where the two axes cross, and the Chaser's motion is plotted with respect to it. The horizontal line is called the V-bar ("Velocity" - approximately in the direction of Target motion) and the vertical line is called the R-bar ("Radial" - pointed straight down to the center of the Earth). The distance the Chaser is from the R-bar, to the right, is how far lagging behind the Target it is. The distance the Chaser is from the V-bar, downwards, is its relative height. You can see in the plot that being in a lower orbit, the Space Shuttle (Chaser) catches up to the ISS (Target). For example, the Space Shuttle's NCC burn here occurs when it is approximately 30 nmi behind and 6 nmi below the ISS. This sort of view allows for planning a rendezvous that might take multiple burns, or multiple orbits, to arrive at the target, and to optimize where on the relative trajectory burns occur. And in using less of a brute force, intercept-and-null rendezvous, it allows for more efficient propellant expenditure.
For fun, here's another example of relative motion plot carried onboard the Apollo 16 LM as a reference for the rendezvous following Lunar ascent that a reddit user restored, on the bottom half of the page, with the inertial orbit also shown above.
Here's the longer explanation, starting with a great article from a former NASA FDO (Flight Dynamics Officer), and an example plot:
The frame shows the relative motion between two spacecraft in orbit, the Target and the Chaser. This plot is in the plane of the Target's orbit - a second plot shows the planar offset of the two spacecraft. The Target is always located at the origin where the two axes cross, and the Chaser's motion is plotted with respect to it. The horizontal line is called the V-bar ("Velocity" - approximately in the direction of Target motion) and the vertical line is called the R-bar ("Radial" - pointed straight down to the center of the Earth). The distance the Chaser is from the R-bar, to the right, is how far lagging behind the Target it is. The distance the Chaser is from the V-bar, downwards, is its relative height. You can see in the plot that being in a lower orbit, the Space Shuttle (Chaser) catches up to the ISS (Target). For example, the Space Shuttle's NCC burn here occurs when it is approximately 30 nmi behind and 6 nmi below the ISS. This sort of view allows for planning a rendezvous that might take multiple burns, or multiple orbits, to arrive at the target, and to optimize where on the relative trajectory burns occur. And in using less of a brute force, intercept-and-null rendezvous, it allows for more efficient propellant expenditure.
For fun, here's another example of relative motion plot carried onboard the Apollo 16 LM as a reference for the rendezvous following Lunar ascent that a reddit user restored, on the bottom half of the page, with the inertial orbit also shown above.
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