What is Cybersecurity in Space?

Satellites, drones, and 5G space links now support critical services such as air traffic, finance, and weather. Yet most were not built to resist modern cyber threats. Ground stations can be breached, GPS jammed, and supply chains compromised, while no shared list of vulnerabilities or safe testing range exists. This paper maps eleven research gaps, including secure routing, onboard intrusion detection, recovery methods, trusted supply chains, post-quantum encryption, zero-trust architectures, and real-time impact monitoring. For each, we outline the challenge, why it matters, and a guiding research question. We also highlight an agentic (multi-agent) AI approach where small, task-specific agents share defense tasks onboard instead of one large model. Finally, we propose a five-year roadmap: post-quantum and QKD flight trials, open cyber-ranges, clearer vulnerability shar ing, and early multi-agent deployments. These steps move space cybersecurity from reactive patching toward proactive resilience.