A new U.S. spy satellite launched into space for a top-secret mission.

The NROL-61 has blasted into space from Cape Canaveral Air Force Station in Florida at around 8 a.m. on July 28 aboard the United Launch Alliance's (ULA) Atlas V rocket.

The NROL-61 mission is operating under the National Reconnaissance Office (NRO), the agency in charge of the U.S.'s fleet of spy satellites. NRO payloads are classified; authorities did not provide any information about the satellite's precise activities, apart from a brief description from ULA stating that NROL-61's mission is being supported by national defense, Space.com reports.

The 20-story Atlas V rocket is powered by 1.5 million pounds of thrust from its Russian main engine and two solid rocket boosters. The ULA rocket will also be used for human launches in the coming years.

"It's a 4-2 configuration of an Atlas V vehicle, which is the same configuration we use to support the crew mission in early 2018 and we're very excited to support this critical national security mission," Tony Taliancich of the ULA said in a statement in News13.

The NROL-61 is the third NRO satellite to launch this year. In February, the NROL-45 launched atop a ULA Delta IV rocket from Vandenberg Air Force Base in California, and in June, the NROL-37 rode a Delta IV Heavy - the most powerful ULA rocket in operation - from Cape Canaveral.

Another mission dubbed NROL-79 is also scheduled to launch atop an Atlas V in December, also from Cape Canaveral.

The NRO mission patch features a cartoon lizard named "Spike," which is depicted launching into space with the Atlas V.

The NRO was formed in 1961, years after the Soviet Union launched Sputnik 1 - the world's first artificial satellite. The agency worked in secret until 1992 when its missions were declassified.

According to the NRO website, its satellites help track international terrorists, develop accurate bombing targets and bomb damage assessments, assess impacts of natural disasters, and monitor the construction of weapons of mass destruction.