ASTEROID aims to provide a fault-tolerant operating system architecture that supports future unreliable many-core systems and is at the same time able to provide real-time guarantees. We believe that this requires co-designing of hardware and critical system software components. We will demonstrate operating system support for software-implemented redundant multithreading. In addition our poster will inform about our approach to a) hardening the critical core of hardware and software components that need to be trusted to provide redundant multithreading, and b) real-time analysis for the ASTEROID system architecture.