- The lifecycle of most spacecraft consists of a final phase where all the systems are tested to various levels of synergy. One of the most important and complex set of tests are the Closed Loop Tests (CLTs), where the spacecraft is sent simulated orbital data, and then its attitude response is observed.
- Volcano (Wikipedia)
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.