In the context of the Horizon Europe project, METASAT, a hardware platform was developed as a prototype of future space systems. The platform is based on a multiprocessor NOEL-V, an established space-grade processor, which is integrated with the SPARROW AI accelerator and connected to a GPU, Vortex. Both processing systems follow the RISCV specification. This is a novel hardware architecture for the space domain as the use of massive parallel processing units, such as GPUs, is starting to be considered for upcoming space missions due to the increased performance required to future space-related workloads, in particular, related to AI. However, such solutions are only currently adopted for New Space, since their limitations come not only from the hardware, but also from the software, which needs to be qualified before being deployed on an institutional mission. For this reason, the METASAT platform is one of the first endeavors towards enabling the use of high performance hardware in a qualifiable environment for safety critical systems. The software stack is based on baremetal, RTEMS and the XtratuM hypervisor, providing different options for applications of various degrees of criticality. The platform has been tested with space-relevant AI workloads taking full advantage of the hardware resources, even when multiple tasks are sharing the GPU.