SpaceX is poised to launch on Thursday a secretive payload known as Zuma for the US government, though the nature of the mission and the agency behind it remain a mystery.
A spy satellite for the U.S. National Reconnaissance Office has been launched from Vandenberg Air Force Base in California.
SpaceX on Sunday postponed for 24 hours the launch of a secretive US government payload, known only as NROL-76, due to a "sensor issue" with the rocket, a spokesman said.
SpaceX on Sunday is scheduled to make its first military launch, with a classified payload for the National Reconnaissance Office, which makes and operates spy satellites for the United States.
Japan launched a new spy satellite on Friday, the country's space agency said, as the region grows increasingly uneasy over North Korea's quickening missile programme.
Israel's latest spy satellite began transmitting pictures on Thursday, the defence ministry said, overcoming initial hiccups on its launch nine days ago.
When you're Thierry Legault and you want to challenge yourself, the bar is set pretty high.
Russia has uncovered a group of spy satellites, the head of its space command said in a film broadcast Sunday, which warned of "enemy" satellites that could masquerade as space junk.
Japan on Thursday successfully launched a replacement spy satellite, its aerospace agency said, as an existing device comes to the end of its working life.
People from New Mexico to Montana saw the bright object break apart as it moved slowly northward across the night sky. Witnesses described it as three "rocks" with glowing red and orange streaks.