The landing of the Falcon 9 rocket took place after it had carried the United States National Reconnaissance Office's NROL-76 spy satellite into orbit.
Following lift-off, the Falcon 9 rocket's first stage booster then successfully landed back at Cape Canaveral Air Force Station.
"And we have touchdown", a SpaceX commentator said on a live webcast as cheers broke out at mission control. Another good day for us at SpaceX.
Seven minutes after liftoff, the first-stage rocket booster separated from the upper stage and fired its engines again. The rocket also marked a successful landing at a nearby pad.
Musk is leading an effort in the rocket industry to re-use costly parts rather than jettison them into the ocean after each launch.
SpaceX previously landed a first stage booster at Landing Zone 1 three times. Even during the Space Shuttle years, NASA had to discard an external tank on every launch and spend months refitting the two solid rocket boosters.
For years, the market for launching USA military payloads was dominated by the United Launch Alliance, a joint venture of Lockheed Martin and Boeing. No details were disclosed about the newly launched NRO satellite.
The privately owned firm, based in Hawthorne, California, has a backlog of more than 70 missions, worth about $10 billion.
She said she did not know when the contract was awarded. While SpaceX publicized the launch and landing, the actual objective or orbit of NROL-76 was not revealed due to national security concerns.