Delta II | Rossi X-ray Timing Explorer

The XTE (X-Ray Timing Explorer), renamed on orbit RXTE (Rossi X-Ray Timing Explorer) mission has the primary objective to study the temporal and broad-band spectral phenomena associated with stellar and galactic systems containing compact objects in the energy range 2--200 keV and in time scales from microseconds to years.

Delta II is an American space launch system developed by McDonnell Douglas, now part of the Delta rocket family operated by United Launch Alliance. With more than 150 missions and a nearly perfect track record, Delta II has established itself as one of the most successful orbital launch systems.

The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947.