A Delta II rocket will push a payload of five small satellites into orbit soon. The satellites were conceived and constructed by a team at the UC Berkeley Space Sciences Laboratory. The satellites will fly within the magnetic field of the Earth to study the northern lights, where sudden eruptions of cosmic energy known as substorms can imperil astronauts, short-circuit the nation's power grids and disrupt global communications. The aim of the new multi-satellite mission is to study the geomagnetic storms and to learn how to predict them so that damage caused can be minimized. The project is code-named THEMIS, and the flight will be the first to be launched by NASDAQ from a single rocket with so many spacecraft. The multiple launch is key, said Vassilis Angelopoulos, principal investigator for the project, because each satellite has to align precisely in the manner of a string of beads, and instruments on board must be able to locate and probe each substorm, regardless of where or when it erupts. The mission, which will last two years or more, should be able to find at least 30 substorms. The mission is very important, said Mr. Angelopoulos, because identical weather processes take pace around the other planets of the solar system and could also be operating at black holes and around recently discovered extrasolar planets that orbit distant stars. Among topics covered are the effects of the substorms, the use of a specialized magnetometer, and current knowledge of substorms.