Picture: NASA/Twitter

Washington - NASA on Thursday successfully launched a mission to explore an area hundreds of kilometres above the Earth where Earth's weather meets space weather.

The Ionospheric Connection Explorer (ICON) launched on a Pegasus XL rocket carried on an aircraft that took off from Cape Canaveral in Florida at 9:59 pm (0159 GMT Friday).

Originally targeting a 9:30 p.m. drop, NASA and Northrop Grumman determined to bypass the first drop attempt due to communication issues, NASA said in an ICON programme blog.

The aircraft flew to an altitude of 12,000 metres over the ocean and dropped the Pegasus XL rocket, which then ignited and carried ICON into orbit.

"This is a fun launch. In my operational function, this is about as good as it gets," said Omar Baez, launch director in NASA's Launch Services Program. "The anxiety level is higher, the adrenaline is flowing, but what a cool way to fly."

The goal of the mission is to determine where Earth's atmosphere ends and space's begin.

The ionosphere stretches from 80 kilometres to about 640 kilometres above the Earth, overlapping the top of Earth's atmosphere and the beginning of space.

Changes in the ionosphere can affect astronauts, satellites and communications signals, and understanding them could help scientists better protect technology and space explorers.

ICON will track changes in the ionosphere by surveying a natural feature of Earth's atmosphere to constantly glow. ICON will photograph this so-called airglow to measure the ionosphere's winds, composition and temperature, NASA said.