NASA spokesman Steve Cole said that was possible because the last track for the satellite included Canada, starting north of Seattle and then in a large arc north then south.
From starting-up to stabilization of the arc, the electric current and voltage usually fluctuate acutely, which makes a great impact on other circuit components.
由电孤启动到正常工作这段时间，电网线路的电流电压波动性较大，往往给电路其它各元件造成强烈的冲击。
3
An ellipse is defined by its bounding rectangle; an arc is a portion of an ellipse defined by a starting Angle and a sweep Angle.