In a satellite constellation, a crosslink refers to:

• A. A data link from a satellite to a ground station.
• B. A link from a satellite to its own payload.
• C. A link from a ground station to a satellite.
• D. A direct radio link between two satellites to relay data.

Answer: (D)

Crosslinking is about inter-satellite communication—a direct radio link that connects two satellites in a constellation so they can relay data between themselves. This setup lets information hop from one satellite to another without always routing through a ground station, which improves coverage, reduces latency, and increases mission resilience.

Links to or from ground stations are ground-to-space or space-to-ground, so they involve Earth's stations rather than two satellites talking to each other. Similarly, a link to a satellite’s own payload is internal to a single spacecraft, not an inter-satellite relay. So the defining idea of a crosslink is the direct inter-satellite path used to move data across the network.