Recent content by MontBlanc2012

  1. M

    Quaternions, rotations and orbital elements

    What sort of transfer orbits do you want to calculate?
  2. M

    Numerical calculation of the Earth-Moon L2 halo orbit family

    Pantanplan: OK, I’ve located the deleted dropbox file. I’ll send to you via PM. P.S. If in the future any one else needs this file, let me know and I will send to you.
  3. M

    Numerical calculation of the Earth-Moon L2 halo orbit family

    Pantanplan: sorry for the slow response - but, of late, I only check in here at O-F once a month or so. I will have a search through my files and see if I can resurrect the spreadsheet.
  4. M

    An update on all things Lissajous and Halo

    The short answer is: yes. However, a bunch of more practical issues (associated with macro-economic concerns and, of course, COVID-19) have stolen much of my attention for the last year or so. At some point, I'm sure, I'll find the time to focus on all things Lissajous once again. Regards
  5. M

    Numerical calculation of the Earth-Moon L2 halo orbit family

    Hi, ShoorDrag Sorry, I don't maintain a webpage or github repository. If I recall, I generated the stable manifold trajectory example using a time reversal trick: let's suppose you that you know the centre-manifold trajectory (e.g.,, by using the L-P expansion scheme as discussed above.)...
  6. M

    Numerical calculation of the Earth-Moon L2 halo orbit family

    Hi, ShootDrag I've attached my Mathematica notebook. This has been added with a '.txt' suffix rather that a '.nb' notebook suffix in order to 'fool' this forum's file uploading service. I suggest that after downloading, you change the file extension back to '.nb' from '.txt'. This notebook...
  7. M

    Numerical calculation of the Earth-Moon L2 halo orbit family

    Hi, ShootDrag Not sure what your level of mathematical background is - but the basic scheme I used as a starting point was the paper: "High-order solutions of invariant manifolds associated with libration point orbits in the elliptic restricted three-body system". I've attached a copy of this...
  8. M

    calculating relative inclination

    Yes, this is the correct expression for the relative inclination.
  9. M

    News Raspberry Pi computer, is it rational?

    I thought I might chip into this discussion. I've recently bought a Raspberry Pi 4 - 4 GB RAM, quad core ARM processor; 1.5 GHz. It has one Gigabit Ethernet port; two USB-3 ports; two USB-two ports; one USB-C port; wifi; bluetooth. The operating card is, by default, confined to an micro-SD...
  10. M

    Textbook Recommendation, Calculus of Variations

    I don't have a recommended textbook, but here's my potted version of Calculus of Variations: Let's suppose that you have a function that is written as the integral: S = \int_a^b L\left(y(x), y'(x)\right)\,dx This reads as 'the integral (over x) of some function, L, that is itself a function...
  11. M

    A Lambert Problem Solver

    Hi, asbjos re: education/occupation. As you might have guessed, I have some background in maths and physics. However, for most of my professional life, I've functioned as a business developer, commercial contract negotiator and a regulator. I have no academic affiliations. re: why am I...
  12. M

    A Lambert Problem Solver

    Lambert’s problem is concerned with the determination of an orbit from two position vectors - an initial point, \mathbf{R}_1; and a final point, \mathbf{R}_2 with radius r_1 and r_2, respectively; a known time-of-flight, \Delta T; and a central Keplerian gravitational field of known...
  13. M

    Changing the argument of periapsis - two-burn solution

    Hi, Vasco - I doubt that the transfer strategy is truly optimal, although I suspect that it is 'close' to being an optimal two-burn solution. The advantage of the proposed solution is that it is relatively straightforward to implement in Orbiter. The way to check optimality would be to set up...
  14. M

    Solar radiation pressure rotation matrix

    I can probably help. But it’s Christmas and I’m traveling over the next few days. I’ll get back to you on this.
  15. M

    From BCI to BCBF and back again

    This is a quick update on the my preceding posts in this thread. Of late, I've been going though a process and updating a number of coordinate transformations so that they are based on quaternion multiplications rather than rotation matrices - see, for example, Quaternions, rotations and...
Top