USA-227

USA-227, known before launch as NRO Launch 27 (NROL-27), is an American communications satellite which was launched in 2011. It is operated by the United States National Reconnaissance Office.

USA-227

Names	NROL-27 NRO Launch 27
Mission type	Communication
Operator	NRO
COSPAR ID	2011-011A
SATCAT no.	37377
Spacecraft properties
Spacecraft type	SDS-3
Start of mission
Launch date	11 March 2011, 23:38:00 UTC
Rocket	Delta IV-M+(4,2) (Delta D353)
Launch site	Cape Canaveral, SLC-37B
Contractor	United Launch Alliance
Orbital parameters
Reference system	Geocentric orbit
Regime	Geosynchronous orbit
Longitude	30.4° West

Launch

United Launch Alliance (ULA) performed the launch of USA-227, using a Delta IV-M+(4,2) launch vehicle flying from Space Launch Complex 37B at the Cape Canaveral Air Force Station (CCAFS). The launch occurred at 23:38:00 UTC on 11 March 2011.^[1] Following liftoff the rocket flew east, placing the satellite into a geosynchronous transfer orbit. By 23:43 UTC, official updates on the status of the launch had been discontinued.^[2]

Mission

Whilst details of its mission are officially classified, amateur observers have identified USA-227 as being a third-generation Satellite Data System satellite in geosynchronous orbit.^[3] The first amateur observation of the satellite was made on 6 April 2011,^[4][5] when the spacecraft was located at a longitude of 30.4° west.^[5] SDS satellites are used to relay data from American reconnaissance satellites to ground stations.