It was on May 31 that NASA again wrote its name and that of SpaceX in the history of space travel. Elon Musk's company opened the space for commercial flights and Crew Dragon played a key role in taking two astronauts to the International Space Station. If the hardware was revolutionary, the software was no less important. The operating system used was very important to manage everything that was involved.
SpaceX will have chosen this operating system for several reasons, the price may have been one of them.
Linux was instrumental in placing SpaceX's Falcon 9 in Space
Space is now closer. At least there is already a private company that took human and cargo to the International Space Station. According to what was made known, the historic launch was also an achievement for the change from proprietary software, to open source, when controlling the Falcon 9 rocket, with a version of the Linux operating system.
For the story, the information remains that on May 30, the SpaceX Crew Dragon was the first private spaceship, after 9 years of absence from these NASA services, to successfully take NASA astronauts Bob Behnken and Doug Hurley to Earth's orbit.
In this process, Elon Musk's company used Falcon 9 rockets, reusable equipment. The Falcon 9 is equipped with Merlin engines powered by a combination of LOX and RP-1 fuel.
However, to manage all this hardware, SpaceX chose the Linux operating system.
**SpaceX: why use Linux to go to Space? **
According to the engineers responsible for programming the Falcon 9:
The Flight Software team has about 35 people. We wrote all the code for the Falcon 9, Grasshopper [Falcon 9 test rocket] and Dragon applications; and we do the work of the main platform, also in these vehicles. In addition, we also write simulation software; flight code testing; we wrote the communication and analysis software deployed at our earth stations. We also work on Mission Control to support active missions.
According to information, the Falcon 9's onboard operating system is a simplified Linux running on three x86 dual-core processors. The flight software itself runs separately on each processor and is written in C / C ++.
You may wonder if the processing hardware is a little old. In fact, the ship's CPUs are far from the best or the latest. These were developed for spaceships, which take years - even decades - to go from the design process to launch.
For example, the International Space Station (ISS) is managed by Intel 80386SX 20 MHz CPUs, vintage from 1988. However, we don't know which chips are used in Falcon 9. Chances are that the design will be at least a decade old older than what you would buy online today.
Special chips protected from radiation
Of course, while these Legacy chips work to control the machine's multiplexer and demultiplexer (C&C MDM), they shouldn't be used for anything. For daily work, astronauts use the HP ZBook 15s with the Linux Debian and Scientific Linux distributions, as well as Windows 10.
GNU / Linux systems function as remote terminals for C&C MDM, while Windows machines are used for basic tasks with access to email, the web, and entertainment.
However, chips that enter space are not common chips. CPUs in space must be protected by radiation. Otherwise, they tend to fail, due to the effects of ionizing radiation and cosmic rays.
These custom processors go through years of design work and then more years of testing before being certified for space flight. For example, NASA hopes that its next-generation, general-purpose processor, an ARM A53 variant we know of the Raspberry Pi 3, will be ready for use in 2021.