Russian Satellite Provokes Concerns

How close is too close for encounters between sensitive spacecraft orbiting Earth? With a mysterious approach to another satellite, Russia’s military may be trying to find out

Rockets vibrate, shake, and flex intensely as they climb into space, and spacecraft packed with delicate scientific instruments must survive those forces. Before any rocket leaves the ground, NASA engineers work to predict how those stresses will affect every part of a spacecraft. To do that, engine