CAPE CANAVERAL, Florida: NASA has launched a satellite to explore the mysterious, dynamic region where air meets space. The satellite — known as Icon, short for Ionospheric Connection Explorer — rocketed into orbit Thursday night. It was dropped from a plane flying over the Atlantic off the Florida coast. The ionosphere is the charged part of the upper atmosphere extending several hundred miles (kilometers) up. It’s in constant flux as space weather bombards it from above and Earth weather from below, sometimes disrupting satellite communications. The more scientists know, the better spacecraft and astronauts can be protected in orbit through improved forecasting. Icon should have soared two years ago, but problems with Northrop Grumman’s air-launched Pegasus rocket interfered. Despite the long delay, NASA says the $252 million mission didn’t exceed its price cap.