Ingenuity had a relatively shoe-string budget and leaned heavily on off-the-shelf components. It was also a technology demonstration rather than anything missio

Ingenuity had a relatively shoe-string budget and leaned heavily on off-the-shelf components. It was also a technology demonstration rather than anything mission-critical, so it didn't need absolute reliability. Which isn't to say that NASA wouldn't necessarily use Linux in mission-critical applications; there exist real-time patches for Linux.