Using a mix of OPIR and ground-based radars to notify leaders of incoming missile attacks.

Using a mix of OPIR and ground-based radars to notify leaders of incoming missile attacks.

• A. ISIS Operations
• B. Nuclear Detonation Detection
• C. Missile Warning
• D. Spacelift

Answer: (C)

The main idea being tested is how integrated space and ground-based sensors provide early warning of ballistic missile launches. OPIR, or Overhead Persistent Infrared, detects the heat signatures of a missile's exhaust soon after launch, giving an early cue to potential threats. Ground-based radars then track the missile's flight, providing precise trajectory data as it climbs and travels, which helps leaders assess danger and cue defensive options. This combination is specifically about warning and decision support before or during an attack, not about launching forces or detecting explosions after the fact. Why this fits the scenario better than the others: the other options involve activities unrelated to providing a phased, proactive alert to leaders about an incoming missile—ISIS operations describe hostile activities by a terrorist group, nuclear detonation detection focuses on detecting explosions after they occur rather than warning about an impending attack, and spacelift concerns launching payloads into space rather than missile warning.

The main idea being tested is how integrated space and ground-based sensors provide early warning of ballistic missile launches. OPIR, or Overhead Persistent Infrared, detects the heat signatures of a missile's exhaust soon after launch, giving an early cue to potential threats. Ground-based radars then track the missile's flight, providing precise trajectory data as it climbs and travels, which helps leaders assess danger and cue defensive options. This combination is specifically about warning and decision support before or during an attack, not about launching forces or detecting explosions after the fact.

Why this fits the scenario better than the others: the other options involve activities unrelated to providing a phased, proactive alert to leaders about an incoming missile—ISIS operations describe hostile activities by a terrorist group, nuclear detonation detection focuses on detecting explosions after they occur rather than warning about an impending attack, and spacelift concerns launching payloads into space rather than missile warning.