Which of the following is NOT an example of space assets?

Cybersecurity is the correct answer because it pertains specifically to the protection of computer systems, networks, and data from theft or damage. While cybersecurity plays a crucial role in the operation and security of space assets, it is fundamentally a terrestrial domain concern focused on information technology and digital systems, rather than being a space asset itself.

In contrast, satellite communications, remote sensing/imagery, and missile defense all involve direct usage of space technology and assets. Satellite communications utilize satellites for the transmission of data and communication signals. Remote sensing/imagery involves using satellites to gather information about the Earth's surface and environment. Missile defense systems often employ satellites for tracking and monitoring threats, showcasing how these technologies are directly integrated within the realm of space operations.