How to Build a CubeSat and Use Open Source 101

Image credit: NASA/JPL-Caltech

What is a CubeSat?

A CubeSat is a tiny satellite; it is cheaper and faster to produce, and also to launch.  

CubeSat was conceived by the California Polytechnic Institute in San Luis Obispo (Cal Poly) and Stanford University in 1999. As the high costs of satellites limit what can be done and by whom, the goal of the small spacecraft was to enable students and researches all over the world to do space explorations on a budget. Therefore, they would help space science. They also wanted to ensure a standard interface, increasing the chances to have it on board of a space launch. The first CubeSats were launched in June 2003 on a Rockot launch vehicle.  

The latest review of CubeSat Design Specification (CDS) maintains the requirements for a standard CubeSat from Cal Poly. One CubeSat is 10 x 10 x 11,35 cm in size and has a maximum mass of 1,33 kg. Multiples CubeSats can be combined to make a larger CubeSat, for example, a 3-Units CubeSat.  

We Interviewed Artur Scholz, our Spacecraft Operations Engineer and founder of LibreCube, to understand more about how CubeSats are built and how the Open Source project works.  

What do you need to build a CubeSat? 

Image Credit: NASA

According to Artur, with a few thousand euros, you can build a basic CubeSat. To make it work, you will need a system similar to the one on a cellphone. ‘’You will need a structure that holds everything together, and it is defined by the CDS, a power system to supply electrical energy. You also will need a communication system to send commands and data remotely, an onboard computer to execute the commands you want the satellite to do. And a payload as well, the instrument that will do what you need, for example, a camera if you want to take pictures. And last, an attitude control for more advanced missions.’’  

According to Artur, the standardization of the format helps to launch a CubeSats faster. Considering that, there are also specifications for the deployment container, where the CubeSat goes and is attached to the launch rocket. As both CubeSats and their deployers have a standardized form factor, they can be fitted in almost all the launch rockets. Before the standardization, it was necessary first to find a launch rocket and see what interface was used. Only then, build the satellite considering the rocket specifications, demanding a launch contract very early in the process. But now you can create the CubeSat independently of the rocket, looking for a launcher at the final stage.  

Using open source to build a CubeSat 

Artur adds that, however, only the outside design of the CubeSat has a specification. For what goes inside, there is no pattern, and the companies and universities prefer to keep it as a secret. The reason why he started LibreCube, ‘’to promote open source for space and particularly to CubeSats. To encourage people to use Open Source for their CubeSat design (hardware and software) and to share this information with other teams for free.’’  As an example of companies that are taking the business opportunity of open source hardware, Artur, cited Arduino, and Raspberry Pi, which are selling their solutions. ‘’With open source, everyone can publish their design, and maybe someone will use and continue it. We want to go a step further; we want to use proper space engineering to design the CubeSat. We want everything to be redundant, no single point of failure for the mission to be successful.’’  

If you want to contribute to Librecube, you need to check CCSDS and ECSS standards; those are the standards used by NASA and ESA. Although most of the content is related to onboard software and firmware, LibreCube has a space for everyone. Even if you are an artist, you can help make the satellites more stylish.   

If that is something you are interested in visit  www.librecube.org.

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Article written by Juliane Verissímo - Marketing Department of VisionSpace