USA-205, also known as Space Tracking and Surveillance System Advanced Technology Risk Reduction (STSS-ATRR), and previously as Block 2010 Spacecraft Risk Reduction is a satellite

Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 operated by the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 Missile Defense Agency

Missile Defense Agency

The Missile Defense Agency is the section of the United States government's Department of Defense responsible for developing a layered defense against ballistic missiles. The agency has its origins in the Strategic Defense Initiative, which was established in 1983 and was headed by Lt...

. It was launched to demonstrate new technology for missile detection early warning systems. The technology demonstrated on STSS-ATRR will be used in the development of the Space Tracking and Surveillance System

Space Tracking and Surveillance System

The United States Missile Defense Agency is developing a Space Tracking and Surveillance System which it will use to research the space-based detection and tracking of ballistic missiles. Data from STSS satellites could allow interceptors to engage incoming missiles earlier in flight than would...

 part of the Space-Based Infrared System

Space-Based Infrared System

The Space-Based Infrared System is a consolidated system intended to meet the United States' infrared space surveillance needs through the first two to three decades of the 21st century...

.

It was launched on a Delta II

Delta II

Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

 7920-10C rocket from Space Launch Complex 2W

Vandenberg AFB Space Launch Complex 2

Space Launch Complex 2 is an active rocket launch site at Vandenberg Air Force Base, in California, USA. It consists of two launch pads. The East pad , which has been demolished, was used for Delta, Thor-Agena and Thorad launches between 1966 and 1972...

 at the Vandenberg Air Force Base

Vandenberg Air Force Base

Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....

 in California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, USA at 20:24:25 UTC on 5 May 2009. The launch was conducted by United Launch Alliance

United Launch Alliance

United Launch Alliance is a joint venture of Lockheed Martin and Boeing. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. U.S...

.