USA-229, known before launch as NRO Launch 34 (NROL-34), is a pair of

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

signals intelligence Signals intelligence (SIGINT) is intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication ( ...

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

s which were launched in 2011. They are operated by the United States National Reconnaissance Office. Both satellites were deployed by a

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 ...

Atlas V Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture be ...

411

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 ...

, which launched from

SLC-3E Space Launch Complex 3 (SLC-3) is a launch site at Vandenberg Space Force Base that consists of two separate launch pads. SLC-3E (East) is currently used by the Atlas V launch vehicle, while SLC-3W (West) has been demolished. Launches from Vand ...

at the Vandenberg Air Force Base. The launch occurred at 04:24 UTC on 15 April 2011. The rocket placed the satellites into a

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...

. By 04:29 UTC, official updates on the status of the spacecraft had been discontinued. Whilst details of the satellites and their missions are officially classified, amateur observers have identified that the Atlas V deployed two satellites, one of which has officially been catalogued as debris. The two spacecraft have been identified as being a pair of third or fourth generation

Naval Ocean Surveillance System The Naval Ocean Surveillance System (NOSS) is a series of signals-intelligence satellites that have conducted electronic signals intelligence for the U.S. Navy since the early 1970s. The first series of satellites were codenamed "White ...

satellites. Amateur observations have located the spacecraft in an orbit with a

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of and an

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of ,

inclined Incline, inclined, inclining, or inclination may refer to: *Grade (slope), the tilt, steepness, or angle from horizontal of a topographic feature (hillside, meadow, etc.) or constructed element (road, railway, field, etc.) *Slope, the tilt, steepn ...

at 63.46° to the plane of the

equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...

. Current generation NOSS satellites are always launched and operated in pairs, and are used to locate and track ships and aircraft from the radio transmissions that they emit.

References

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