The Falcon 9 rocket launched from Cape Canaveral, Florida, in the early hours of Sunday morning, lifting a Japanese communications satellite called JCSAT-16 into geostationary orbit.
Around nine minutes later, after depositing the satellite, the Falcon 9 became the sixth rocket to land. The landing is significant because it means SpaceX has now landed more rockets than it has crashed. Overall the company has attempted to land 11 rockets, with five of them failing.
Prior to the launch, SpaceX had warned that this landing would be difficult, because JCSAT-16 had to be carried into a highly elliptical orbit some 22,300 miles above the Earth's equator.
"The first stage will be subject to extreme velocities and re-entry heating, making a successful landing challenging," it said.
Musk has previously expressed his desire for SpaceX to be the first private company to land on Mars - with plans to send his Dragon spacecraft to the Red Planet by 2018.
He has also said that reusable rockets could eventually make it possible for humans to colonise Mars, and has suggested dropping a nuclear bomb on the planet, to heat up the atmosphere and make is more suitable for human habitation.
"I think it really quite dramatically improves my confidence that a city on Mars is possible," he said, following the first successful Falcon 9 landing. "That's what all this is about."
SpaceX is not the only company pursuing reusable rocket technology. Blue Origin, the company founded by Amazon chief executive Jeff Bezos, launched and landed a reusable rocket booster for the third time in April.
Blue Origin's New Shepard rocket launched into suborbital space from the company's West Texas test site, then descended gracefully back to Earth and landed vertically - on the same Launchpad it had lifted off from only minutes earlier.
As well as space tourism, suborbital spaceflight opens the door to a range of scientific research and technological development - from biotech and materials science to fluid physics and engineering.