You are seeing poliastro blog. If you want to see documentation, the latest version can be found in docs.poliastro.space.

Articles by Jorge Martínez Garrido

New propagators

What are propagators and why do we care about them?

One of the most common problems in astrodynamics and orbital mechanics is that we want to know where a body will be at a given position along its orbit for a given time. It is possible to integrate by hard the two-body equation and then apply some boundary conditions. However, this last option is just insane and would take several hours or days to be done by a human.

There is a better way to get the position as a function of time or propagate an orbit. Johannes Kepler's contributions to the astrodynamics and orbital mechanics field were really important and can be summarized here, in the so-called Kepler's Laws:

  • Planets' orbits follow an elliptical path around the Sun, which is located in one of the focus.
  • Planets cover equal …

Getting done for next release

Version 0.13 is getting closer

Version 0.13 is expected to be tagged in about a month. As any other release, it includes new features such as a new method in the Orbit class called change_attractor or the trail parameter in StaticOrbitPlotter. However, this release will also include really important bug fixes such as:

  • Minor issues related to Lambert's problem.
  • Propagator's are supposed not to hang out anymore due to robust solutions and propagation methods.

Now that my final exams ended I am completely free to work in poliastro and direct all my efforts to the software. I want to close issues #495 and #475 in the next days since they are previously commented bugs.

Propagator methods in the twobody problem

Kepler's equation (KE) allows us to solve either for the time at a given position or the position …

Lambert maneuvers and trails in plots

What's new?

Three weeks have passed since the coding phase began and new features have been added to the software:

  • Lambert is now a Maneuver instance.
  • A trail keyword in StaticOrbitPlotter for showing orbits' trails.

Lambert just needs now two orbits!

Although the raw algorithms are kept under the module poliastro.iod, it is possible now to simplify the process of solving this famous astrodynamics problem by making use of the poliastro.maneuver module.

Imagine that we want to solve the classical problem ongoing from Earth to Mars for a trip of 600 days duration. Let us compare before and after Maneuver.lambert implementations:

With 0.12 version:

from astropy import units as u
from astropy.time import Time

from poliastro.bodies import Earth, Mars, Sun
from poliastro.iod.izzo import lambert
from poliastro.twobody import Orbit

LAUNCH = Time.now …

Coding phase starts!

The End of the bonding period

Today bonding period ends for all students selected at GSoC'19. The aim of this period was to learn more about your project community: get in touch with mentors, other developers and their future ideas on the software...

As I said in my last post, I started contributing to poliastro several months ago, even before GSOC was announced. Therefore, and since I am taking my final exams, all my efforts were towards passing them.

But today the coding phase starts! That means we all should start working on our proposal features.

The coding phase at poliastro

The release of poliastro version 0.13 is getting closer. During this first part of the coding phase, I am planning to solve for different issues, most of them related to frames, check out milestones 0.13.

Frames are …

GSOC-19 starts!

From my first pull request to GSOC student

Hi, my name is Jorge, and I am one of the selected students for this GSOC edition at poliastro under the OpenAstronomy organization. I started working on poliastro project after Juanlu came to my university to give a talk about Open Source software in engineering.

After forking poliastro, I decided to improve API Docs, which gave me an overview on how the project was built and how the different modules talked among them. I had no idea on how Git and GitHub worked and therefore, when finished with the docs my first pull request was quite massive...

But after that I started feeling more confortable with GitHub and Sphinx, the tool used nowadays in poliastro for building documentation. Then, I decided to work on a porkchop plotter.

I spent the week after …