Long time, no see!
As some of you may know, I am the mission architect and the technical responsible for the attitude and orbit control subsystem (AOCS) of the Brazilian satellite Amazonia-1, launched on Feb 28. This is an image obtained by the first recording procedure:
Here you can see the big city of São Paulo (on the left), São José dos Campos where INPE is located (“small” city on the top right), and the beautiful Brazilian shore, showing Santos, Guarujá, Bertioga, São Sebastião, and Ilhabela (the small island on the right).
OK Ronan, but this is a Julia forum, do you know?!
I just want to share with you guys a very successful usage of Julia. Since 2013, when I got involved with the project, I started to use Julia to do all the kind of analysis. The first version of SatelliteToolbox.jl dates back to 2014, during v0.3.0 days. In this package, I added a lot of functions related to satellite and orbit analysis, which was eventually used in the Amazonia-1 project.
I used Julia in the following tasks:
- General mission analysis such as fuel budget computation, orbit planning, ground station visibility analysis, etc.
- The Amazonia-1 AOCS simulator is 100% written in Julia using the amazing DifferentialEquations.jl ecosystem. The results obtained from it greatly match the real satellite dynamics obtained after the orbit injection.
- The AOCS telemetry analysis system is also 100% written in Julia. The problem with AOCS is that you often need to get a lot of data from the satellite telemetry and plot many graphics. During the integration and testing, I needed to do this daily. Hence, we developed inside INPE a Julia package that automatically fetches the raw telemetry from the database, process, and output what we want. Today I can very easily see the overall satellite AOCS state with just two or three commands.
- The in-orbit sensor calibration required the implementation of Kalman filters, which, of course, was coded in Julia.
We can now say that Julia is truly a part of the Brazilian space program
Finally, I want to thanks all you developers that created Julia and the fantastic package ecosystem. It really made a lot of difference to me! I am 100% sure that I would have a lot more work if I had to use another computing language.