# Tag Info

13

Full disclaimer: I'm the author and main developer of poliastro. The most important step before doing anything is somehow retrieving the positions and velocities of the planets of the Solar System. Astropy, one of the core dependencies of poliastro, ships medium-precision approximate models described in Simon et al "Numerical expressions for precession ...

10

Disclaimer: I'm the author of poliastro No matter how many revolutions you consider, the Lambert solution gives always two velocities: departure and arrival. You could then consider that you need two impulses: one to attain the departure velocity, and one final impulse to fix the orbital velocity (because you arrived at the position you wanted, but maybe ...

6

If I'm understanding your problem statement correctly, your maneuver is equivalent to a complete Hohmann transfer from 200km x 200km to 700km x 700km, followed immediately by the first burn (but not the circularization burn) of a second Hohmann from 700km to 8000km. The online Hohmann calculator here confirms your ∆v calculations. The Tsiolkovsky equation ...

6

I would highly recommend NASA Goddard's GMAT (General Mission Analysis Tool). It is quite user friendly, has a number of tutorials, and has been used in spacecraft operations.

3

Full disclaimer: I'm the author and main developer of poliastro. In poliastro there are several perturbations already defined, and among them you have zonal harmonics, Solar pressure, and the gravitational effect of the Moon. You can see the full list of perturbations here: http://docs.poliastro.space/en/latest/api.html#module-poliastro.twobody....

3

You need to take into account that the Hohmann transfer and the Lambert solution receive different inputs and are therefore not equivalent. The Hohmann transfer is known to be the optimal two-impulse transfer between two coplanar, circular orbits. There are several proofs to this. The initial and final states are defined by position and velocity. Therefore, ...

1

If both orbits are in the same plane, then the optimal solution will be called hohmann transfer where you need to start from perigee of the inner orbit towards an apogee of the outer orbit. So you will start from 200 km perigee and end at 8000 km apogee. I hope this is clear now.

1

Summarizing some answers from the poliastro issue: The Lambert problem is nothing more than the two body boundary value problem under the assumption of Newtonian dynamics and spherical gravity. Therefore, to solve a case with a different gravity field, you would need to write the equations of motion and use a boundary-value problem solver. I don't know of ...

Only top voted, non community-wiki answers of a minimum length are eligible