The Delta N or Thor-Delta N was an American

United States

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

 expendable launch system

Expendable launch system

An expendable launch system is a launch system that uses an expendable launch vehicle to carry a payload into space. The vehicles used in expendable launch systems are designed to be used only once , and their components are not recovered for re-use after launch...

 used for nine orbit

Orbit

In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

al launches between 1968 and 1972. It was a member of the Delta family of rockets, and the last Delta to be given an alphabetical designation - subsequent rockets were designated using a four digit numerical code.

The Delta N consisted of two stages. The first stage was the Long Tank Thor, a stretched version of the Thor

PGM-17 Thor

Thor was the first operational ballistic missile of the U.S. Air Force . Named after the Norse god of thunder, it was deployed in the United Kingdom between 1959 and September 1963 as an intermediate range ballistic missile with thermonuclear warheads. Thor was in height and in diameter. It was...

 missile, previously flown on the Delta L

Delta L

The Delta L, Thor-Delta L, or Thrust-Augmented Long Tank Thor-Delta was an American expendable launch system used to launch the Pioneer E and TETR satellites in 1969 and HEOS satellite in 1972. It was a member of the Delta family of rockets.The Delta L was a three stage rocket...

 and Delta M

Delta M

The Delta M or Thor-Delta M was an American expendable launch system used for thirteen orbital launches between 1968 and 1971. It was a member of the Delta family of rockets....

. Three Castor-2 solid rocket booster

Solid rocket booster

Solid rocket boosters or Solid Rocket Motors, SRM, are used to provide thrust in spacecraft launches from the launchpad up to burnout of the SRBs. Many launch vehicles include SRBs, including the Ariane 5, Atlas V , and the NASA Space Shuttle...

s were attached to increase thrust at lift-off. A Delta E was used as the second stage. If an increased payload capacity was required, six boosters were flown instead of three, in a configuration known as the Delta N6, or "Super Six". Three launches used the N6 configuration.

Delta N rockets were launched from Launch Complex 17A

Cape Canaveral Air Force Station Launch Complex 17

Cape Canaveral Air Force Station Space Launch Complex 17 , previously designated Launch Complex 17 , was a launch site at Cape Canaveral Air Force Station, Florida used for Thor and Delta rocket launches between 1958 and 2011....

 at the Cape Canaveral Air Force Station

Cape Canaveral Air Force Station

Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...

, and SLC-2

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 Vandenberg AFB. One of the launches, a Delta N6 with ITOS B, failed. The satellite was placed into an incorrect and unusable orbit.