The rocket booster will attempt to land on one of SpaceX's autonomous drone ships in the Atlantic Ocean.
The 229-foot-tall (70-meter) launcher reached an altitude of more than 40 miles (65 kilometers) in two-and-a-half minutes, then the Falcon 9's first stage shut down and separated, leaving an upper stage engine to continue firing to propel the rocket and its payload to the velocity needed to enter orbit.
The rocket landing was the 19th that SpaceX has pulled off during orbital launches.
First stage entry burn complete. This newest Koreasat will replace a failed satellite launched in 2006, and serve both Asia and the Middle East.
The approval of flight-proven rockets for NASA launches is a strong indication of the trust the space agency has come to put in SpaceX. If the launch is successful, it will be the company's 16th of the year - more than all of 2015 and 2016 combined.
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He thought it was a "cool epidemiological paper" that "did the best it could with the data", but it did have limitations. To determine what the problem is, they'll go through a laundry list of regular activities.
Koreasat-5A is the second satellite launched this year for South Korean satellite operator KT Sat, following an Ariane 5 dual launch of Koreasat-7 and Brazil's SGDC satellite in May.
The Falcon 9 shall send the 8000-pound communication satellite Koreasat-5A to an orbit 2,000 miles over the equator.
The satellite will provide television broadcast and other communication services over South Korea, Japan, the Philippines, Guam, Indochina and South Asia. Problems with the satellite's solar arrays have forced the communications company to retire the craft.
That's double last year's count, and 2017 still has two months remaining. It is meant to replace Koreasat-5, launched in 2006, to provide high-speed Ku-band television and data across Asia and the Middle East along with maritime coverage over the Persian Gulf, the Indian Ocean and the China Sea. Lower prices have helped SpaceX expand its USA government customer base. The webcast below should begin about 15 minutes before the launch window opens.