Orbital Sciences [ORB] last Thursday reported a decline in second quarter sales but an increase in net income due mainly to lower interest expense and to a lesser degree higher operating income. Orbital's Taurus space launch vehicle. Photo: Orbital Sciences Corp. Sales fell 10 percent to $333.1 million in the quarter from $371.3 million a year ago due to declines in its satellites and space systems and advanced space programs segments. Orbital’s launch vehicles segment posted higher sales. Net income rose…