USA-227, known before launch as NRO Launch 27 (NROL-27), is an American

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. C ...

which was launched in 2011. It is operated by the United States National Reconnaissance Office.

Launch

United Launch Alliance United Launch Alliance (ULA), legally United Launch Alliance, LLC, is an American spacecraft launch service provider that manufactures and operates a number of rocket vehicles that are capable of launching spacecraft into orbits around Earth, a ...

(ULA) performed the launch of USA-227, using a Delta IV-M+(4,2)

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...

flying from Space Launch Complex 37B at the

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the statio ...

(CCAFS). The launch occurred at 23:38:00 UTC on 11 March 2011. Following liftoff the rocket flew east, placing the satellite into a

geosynchronous transfer orbit A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step f ...

. By 23:43 UTC, official updates on the status of the launch had been discontinued.

Mission

Whilst details of its mission are officially classified, amateur observers have identified USA-227 as being a third-generation

Satellite Data System The Satellite Data System (SDS) is a system of United States military communications satellites. At least three generations have been used: SDS-1 from 1976 to 1987; SDS-2 from 1989 to 1996; SDS-3 from 1998 to the present. It is believed that ...

satellite in

geosynchronous orbit A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...

. The first amateur observation of the satellite was made on 6 April 2011, when the spacecraft was located at a

longitude Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter l ...

of 30.4° west. SDS satellites are used to relay data from American reconnaissance satellites to

ground station A ground station, Earth station, or Earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves fro ...

References

Spacecraft launched in 2011 Spacecraft launched by Delta IV rockets USA satellites {{US-spacecraft-stub