# Search results

1. ### GMAT Mars transfer orbit model

It's windows in days where to search for an optimal trajectory. With 0 it just calculates for selected dates. If True - ignore minimal dV needed for the final maneuver (orbital insertion) and optimize only for departure dV (and dV at flybys for multybody trajectories). Days or dates. With...
2. ### GMAT Mars transfer orbit model

Just select flyby parameters. It was initially designed by Keithth G to find and optimize trajectories with multiple gravity assist maneuvers. But nothing prevents to use it with simple trajectories. For example: import sys import pygmo as pg from flyby import flyby p = flyby(['earth', 'mars']...
3. ### GMAT Mars transfer orbit model

Just use some porkchop plotter application. I even made one many years ago ( https://www.orbiter-forum.com/resources/lambertsolver.3050/ ) But now it's easier to use online porkchop plotters, e.g.: http://sdg.aero.upm.es/index.php/online-apps/porkchop-plot
4. ### GMAT Mars transfer orbit model

BTW, for Earth-Mars transfer the departure at 2040-May-07 and arrival at 2041-Sep-12 are far from optimal dates: Date of earth departue : 2040-May-07 00:00:00 Date of mars arrival : 2041-Sep-12 00:00:00 Transfer time from earth to mars: 493.0 days Total mission duration...
5. ### GMAT Mars transfer orbit model

The easiest way to use the lamber solution with GMAT is to convert v-infinity at departure to GMAT's OutgoingAsymptote (OutgoingC3/OutgoingRHA/OutgoingDHA) and then optimize it in GMAT. Take a look at https://orbiter-forum.com/threads/pykep-to-transx-conversion.33685/#post-514495
6. ### News Roscosmos News

And the recording is a deepfake? :cool:
7. ### News Roscosmos News

They published the story here (in German): https://www.bild.de/bild-plus/politik/ausland/politik-ausland/bild-hat-geheime-telefon-mitschnitte-russen-planen-mega-angriff-auf-kiew-85847600.bild.html
8. ### News Roscosmos News

@BILD obtained secret voice recordings between former Roscosmos chief Dmitry Rogozin and current (sate-owned) Progress CEO Dmitry Baranov in which they prepare and finalize a plan to crash a “civilian” #Soyuz carrier rocket into #Kyiv or another Ukrainian city. 🤬
9. ### Challenge LOP-G to Brighton Beach and Back Again

It may be easier to find a way to get back from NRHO to Earth using Backward Propagation. But with 2 maneuvers from the scheme it will still be a challenging task.
10. ### Challenge LOP-G to Brighton Beach and Back Again

The coordinate systen is nothing to do with this. The inclination is not exactly 90 degrees, so it's not a polar orbit strictly speaking, but it's close enough to the one. I think, at the periapsis you don't need to get into the NRHO at once, you just have to make a correction to reach the NRHO...
11. ### Challenge LOP-G to Brighton Beach and Back Again

The spacecraft never gets there. It's NRHO, but RadApo is calculated for an elliptical orbit. Just a guess. It varies RadApo and Inclination to find a solution, but the Inclination is a parameter for an elliptical orbit too. RadApo/RadPer/Inclination are just the simpliest way to set initial...
12. ### Challenge LOP-G to Brighton Beach and Back Again

Not exactly 7 days. It stops propagating when SC crosses YZ-plane (SC.LunaEarth.X = 0) in the Earth-Moon rotating frame. It's at the apoapsis and the periapsis. And it tries to minimize differences in position/velocity at the periapsis compared to the initial values. The script above gives...
13. ### Challenge LOP-G to Brighton Beach and Back Again

@firefox00 Don't look at RadApo. It's a keplerian apoapsis, not real. You can trust RadPer here (because it's the starting point) but not RadApo. So, change RadPer to your periapsis (3000km), reduce numbers of orbits to 3 (For I = 1:1:3;), run, apply correction, run again, apply, increase to 4...
14. ### Challenge LOP-G to Brighton Beach and Back Again

@firefox00 It was calculated by a GMAT script that looked like the script in the attachment.
15. ### General Question Rendering issues with D3D7 and D3D9 clients (Open Orbiter)

D3D7Client in Orbiter.exe and D3D7Client in Orbiter_ng.exe work differently. Сheck also 'Delta-glider\Brighton Beach.scn' for example.
16. ### Better Ephemerides, Rotation Models, and a Solution to X64 Builds

It's ~34Mb. But now it won't work very well outside of this 5 years. I've been testing this today, the elliptical orbits calculated on the edges of the kernel interval are very inaccurate. Pre-calculated mean orbits would be more accurate, but it will be impossible to connect them seamlessly...
17. ### Better Ephemerides, Rotation Models, and a Solution to X64 Builds

It depends on the number of celestial bodies and the time period it covers. I currently use the orbiter.bsp file, which is approximately 600MB in size, as described here: https://orbiter-forum.com/threads/better-ephemerides-rotation-models-and-a-solution-to-x64-builds.41231/post-609141 If there...
18. ### Better Ephemerides, Rotation Models, and a Solution to X64 Builds

Additionally, this module has the ability to function beyond the time period covered by SPICE kernels. It calculates osculating elements at the boundaries of the period and utilizes them outside the designated timeframe. This feature can help address the issue of distributing a large *.bsp file...
19. ### Better Ephemerides, Rotation Models, and a Solution to X64 Builds

I've updated the SPICE celestial body module for Orbiter and published it on GitHub: https://www.orbiter-forum.com/threads/spice-module.1108/post-609388 https://github.com/Ajaja/spice_orbiter
20. ### SPICE module

I have made significant changes to the SPICE celestial body module for Orbiter and have decided to publish it on GitHub: https://github.com/Ajaja/spice_orbiter The main change is the implementation of cubic spline interpolation. Prior to this modification, calculating the positions of celestial...