But spy satellites launched into polar orbits are typically used for photo or radar reconnaissance, able to observe targets anywhere in the world as the planet rotates below.
That Falcon 9 rocket launch delivered 10 satellites into low-Earth orbit for Iridium, a communications company. The rocket launched a national security payload, designated NROL-47, for the U.S. National Reconnaissance Office (NRO) in support of a national defense mission. NROL-47 will join the Future Imagery Architecture (FIA) satellite constellation, which flies under the code name Topaz.
The mission - dubbed NROL-47 - is classified, so we don't know much about the payload and what it'll be used for once in orbit. It performs launch services for the USA government at Vandenberg and Cape Canaveral Air Force Station in Cape Canaveral, Florida. The mission was ULA's 27th flight for the National Reconnaissance Office (NRO) and the 36th flight of the Delta IV rocket, which first flew in 2002.
With more than a century of combined heritage, United Launch Alliance is the nation's most experienced and reliable launch service provider. The forecast shows a 90 percent chance of favorable weather conditions for launch.
The mission was due to take place at Space Launch Complex-6 - around 140 miles from downtown Los Angeles in California.
The Delta IV rocket was built in Decatur, Alabama. The Delta IV M+(4,2) uses two strap-on solid rocket motors (SRMs - GEM-60 boosters provided by Orbital ATK) to augment the first-stage CBC and a 4-m diameter PLF.
The launch was then delayed by about an hour due to a ground system helium issue.
Sunday's launch was SpaceX's third classified mission.
"We are proud to provide this national defence capability and every Team V member involved has tirelessly worked to ensure the launch is safe and successful".