A more thorough explanation:

MDA

MDA stands for Missile Defense Agency. It is a government agency responsible for developing and testing missile defense systems to protect the United States and its allies from missile attacks.

One example of MDA's work is the development of the Ground-based Midcourse Defense (GMD) system, which is designed to intercept and destroy incoming ballistic missiles. Another example is the Aegis Ballistic Missile Defense System, which is used on Navy ships to detect and intercept missiles.

These examples illustrate how MDA is working to protect the United States and its allies from missile attacks by developing and testing advanced missile defense systems.