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Probably Too late for me to do much this evening. But I'll have a think about it tomorrow.

see https://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles for the general conversion rule for converting from a quaternion to Euler angles.

I have to do a few chores for a few hours. When I finish, I'll respond in more detail. ---------- Post added at 07:26 AM ---------- Previous post was at 12:17 AM ---------- OK, here's the same thing in a bit more detail - using Lua script-like commands: sObj = Object Handle or the Sun...

Step 1: use OAPI's GetGlobalPosition function to return the position of the Sun, your position (i.e., the relevant point on the surface of Mars), and the centre of Mars. Step 2: calculate a vector from the Sun to your position. Call it SunPos. Calculate a vector from the centre of Mars to...

I had a closer look at Belbruno's paper on ballistic transfers to Mars. Having thought about it, Belbruno's (ballistic) technique is unlikely to result in a lower delta-v cost transport to Jupiter from Earth. Belbruno's technique relies upon riding the stable manifold of the L1 point and...

What are you trying to do here? Calculate the apparent position of the Sun in the sky from an arbitrary point on an arbitrary planet/moon?

In this post, I present some general musing about Belbruno & Topputo's "Earth-Mars transfer with ballistic capture" paper. These musings are a consequence of thinking about how to achieve capture by any of the Galilean moons 'on the cheap' with as low a delta-v budget as possible. Much of this...

Basically, one just loads the unzipped '.scn' file into the "Scenarios" folder in Orbiter. Then, open up Orbiter and in the main Launchpad window, select the scenario. ---------- Post added 08-17-15 at 05:30 AM ---------- Previous post was 08-16-15 at 02:17 PM ---------- In an earlier post...

As promised, attached is a scenario file which has a Delta Glider (roughly) on the stable manifold - starting at about 5 years before arrival at the stable manifold. This scenario starts with the Delta Glider in an elliptical orbit around the sun with an eccentricity around 0.2 and with solar...

What is absolutely true is that there is a set of trajectories that, if on that trajectory will have you terminate at a Lagrange 'point' as the inevitable dynamical consequence of being on that trajectory. If you are on one of these trajectories, i.e., on the stable manifold of the Lagrange...

RGClark Yes, I agree. But, as yet, I don't know how to do that. ---------- Post added 08-13-15 at 03:17 AM ---------- Previous post was 08-12-15 at 02:41 PM ---------- RGClark Just as a quick addition to my earlier reply: It occurs to me that the 'obvious' thing to do is to exploit the...

RGClark I would interpret the numbers slightly differently. I think that the "Broken Plane" cost of 200 m/s is a deep space manoeuvre that takes place along the Hohmann transfer from Earth to Jupiter needed to align the craft with Jupiter's orbital plane. In my calculations, I've assumed that...

I've calculated the cost of using Ganymede/Callisto periapsis to achieve JOI. Using the same assumptions of a Jovian arrival speed of 5.35 km/s and the same target apojove (25 million km) as in previous posts, I calculate that: 1. At periganymedion (good word!), one needs a retrograde burn...

The 'textbook' way of getting to a halo orbit is to calculate the stable manifold for that orbit. The stable manifold is a kind of 'tube' that extends away from the halo orbit. If you get onto the tube, with the right speed and heading (calculated alongside the calculation the location of the...

Since, Orbiter models Newtonian gravity really rather well, Lagrange points are very much part of its core gravity model. However, there are (as far as I know) no tools that map trajectories to or from the Lagrange points and, in particular, there are no tools that map halo trajectories...

RGClark Earlier, you asked: The short answer to this question is that if: 1. you approach the Jupiter system with a hyperbolic excess velocity of, say, 5.35 km/s; and 2. you execute a 324 m/s retrograde burn at Jupiter periapsis; and then a further 345 m/s prograde burn at Jupiter apoapsis...

RGClark Interesting stuff. Although I suspect that if one works hard enough, one could find a truly ballistic trajectory that leads to Europa capture. And, yes, this would require making use of a series of Lagrange points, i.e., requiring considerable familiarity with '3-body physics'...

RGClark Orbiter most certainly can do three-body simulations. Actually, Orbiter's core n-body integration engine is surprisingly accurate and there is no reason to believe that it could model close encounters with Europa (or any other body for that matter) with some considerable fidelity. If...

RGClark You are correct in having guessed that the change in hyperbolic excess velocity does not change the results significantly. Here are the updated results using an updated value of the hyperbolic excess velocity of 5.35 km/s. The 'Oberth' capture burn is very efficient at shedding...

Hi, RGClark Earlier you asked: I've calculated the total delta-V requirement for doing a capture (Oberth) burn around Jupiter at a radius r_0, followed by a circular orbit insertion burn around Europa with 71000\,km \leq r_0 \leq 700000 \,km. This calculation covers the range from the...