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Cristiapi Strictly speaking, Lagrange points are only well-defined 'points' in the CR3BP and the ER3BP - i.e., only in specific classes of restricted three-body mathematical models. In a general n-body system, the Lagrange points do not (strictly speaking) exist since you will never get a...

Not sure I followed perseus' comments fully, but the link referenced by dgatsoulis made a lot more sense to me. At the risk of a little plagiarism, the core of the calculation of the position of L1, say, is to solve the equation...

ADSWNJ I'm broadly familiar with your Lagrange MFD - I've even used it a couple of times to construct ad hoc, low-energy transfers from Each to the Moon and back again. Although I'm quite pleased with the Lambert Solver I've introduced in this thread, I'm conscious that I have still a fair bit...

Thorsten I haven't described the solver in detail in part because the maths is probably a little too much for most on this forum; and partly because setting out the details will take considerable effort. But, in brief: The solver is configured as a single-step very high-order symplectic...

For a while now, I've been thinking about the kinds of tools that one needs to navigate efficiently and effectivel in the vicinity of the Lagrange points of, say, the Earth-Moon system. To be sure, Orbiter has a number of lesser-known (but quite sophisticated) tools in the Orbiter MFD stable -...

For anyone interested, here is the link to the spreadsheet tool to calculate the two tangent burns needed to change the argument of periapsis by a prescribed amount. Link to spreadsheet (Sorry for the delay in posting the link to the spreadsheet, but it has taken me a while to realise that...

Orbi, I assume you want to know how to implement the 'single burn' method of changing the argument of periapsis as outlined above. If so, then the procedure is to execute a burn of the required magnitude along the radial vector (i.e., the vector that starts from the centre of the Earth and...

This note follows on from Changing the argument of periapsis - single-burn solution. In that note, a single-burn method for changing the argument of periapsis was examined. Here, we consider a two-burn method that is considerably more fuel efficient at moving the argument of periapsis (while...

In this note, I want to consider the single-burn manoeuvre needed to change the 'argument of periapsis' of an elliptical orbit by an angle \Delta\omega. Whereas we know how to raise and lower the periapsis radius, r_p, and/or apoapsis radius, r_a, of an orbit to achieve a desired semi-major...

I can't help with your take-offs but here's my take on the realism parameters. Non-spherical gravity sources If this parameter is switched off, Orbiter assumes that the Earth is a perfect sphere. This is assumption is almost true but in reality the Earth is slightly flattened at the poles and...

This note presents the conditions that need to be satisfied for two elliptical orbits to 'touch' at a point. It follows on from an earlier thread by 'maki' entitled "calculating intersection of two orbits" (https://www.orbiter-forum.com/showthread.php?t=39048. Knowledge of these conditions is...

I've come to this a bit late but, for what it's worth, here's my response to the question of the intersection of two co-planar orbits. Now, I'm going to break up the answer into two parts. The first part (in this post) will just focus on the simple case where the argument of periapsis of both...

Here is a straightforward challenge designed to test skills in orbital mechanics: Ordinarily, this (somewhat arbitrary) orbit transfer could be constructed from a plane change manoeuvre; a retrograde burn to lower periapsis; and then another retrograde burn to lower apoapsis - so, three...

Thanks. I'll have a look.

This is a follow on from dgatroulis' post Elliptical trajectory from 3 points and focus?. In effect, dgatsoulis posed the question: what is the elliptical arc that connects two points separated by an angle \theta for a known apoapsis radius? A number of solutions were given in comments. This...

Hi, Brian I don't think this interpretation is quite right. TransX uses the term 'escape' to refer to trajectories that have sufficient energy (kinetic and potential) to leave the gravitational influence of a minor body such as the Earth. So, in TransX's stage 1, to go from Earth to Mars...

No, not especially. The solution I found was actually two days in the future. What this shows, I think is that so long as one isn't aiming for the absolute lowest possible dV requirement, the solution to this problem is quite date tolerant offering a fairly large transfer window. ----------...

And here is a link to a sample solution to this challenge: Best viewed with subtitles on.

This challenge is a similar transfer to an earlier "Low energy Moon-Earth transfer" challenge. The scenario starts with DeltaGlider in a standard 300 x 300 km Low Earth Orbit. It has 3475 m/s of main and RCS fuel. The objective is straightforward: transfer the DeltaGlider to a circular lunar...

A very reasonable solution. Although we can set up low energy transfers of this kind using IMFD, we can't ensure that these transfers are 'optimal'. However, I suspect that with a bit of tweaking with dates and prograde quantities, we an get to within 5 - 10 m/s of the optimal amount without...