Stargazer, registration number

Aircraft registration

An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...

 N140SC, is a modified Lockheed L-1011

Lockheed L-1011

The Lockheed L-1011 TriStar, commonly referred to as the L-1011 or TriStar, is a medium-to-long range, widebody passenger trijet airliner. It was the third widebody airliner to enter commercial operations, following the Boeing 747 and the McDonnell Douglas DC-10. Between 1968 and 1984, Lockheed...

 TriStar aircraft used by Orbital Sciences Corporation

Orbital Sciences Corporation

Orbital Sciences Corporation is an American company which specializes in the manufacturing and launch of satellites. Its Launch Systems Group is heavily involved with missile defense launch systems...

 as a mother ship

Mother ship

A mother ship is a vessel or aircraft that carries a smaller vessel or aircraft that operates independently from it. Examples include bombers converted to carry experimental aircraft to altitudes where they can conduct their research , or ships that carry small submarines to an area of ocean to be...

 launch pad

Launch pad

A launch pad is the area and facilities where rockets or spacecraft lift off. A spaceport can contain one or many launch pads. A typical launch pad consists of the service and umbilical structures. The service structure provides an access platform to inspect the launch vehicle prior to launch....

 for Pegasus rockets. , 34 rockets have been launched from it, using the Pegasus-H and Pegasus-XL configurations.

The first Pegasus launch to use Stargazer was conducted on 27 June 1994, and was the maiden flight of the Pegasus-XL. Previous launches used the NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

-operated Boeing

Boeing

The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

 NB-52B

B-52 Stratofortress

The Boeing B-52 Stratofortress is a long-range, subsonic, jet-powered strategic bomber operated by the United States Air Force since the 1950s. The B-52 was designed and built by Boeing, who have continued to provide maintainence and upgrades to the aircraft in service...

 "Balls 8

Balls 8

Balls 8 was a NASA Boeing NB-52B mothership. It derives its nickname from its NASA tail number 52-008: leading zeroes plus the number 8. Among USAF personnel it is common practice to refer to aircraft whose tail number is a single number preceded by multiple zeros as "Balls" and the last number of...

", which was also used for four subsequent launches, as the original Pegasus could not be launched from Stargazer due to clearance issues. A modified version, the Pegasus-H, was introduced to rectify this.

In addition to Pegasus launches, Stargazer was used for captive tests and transportation of the X-34

Orbital Sciences X-34

The Orbital Sciences X-34 was intended as a low-cost testbed to demonstrate "key technologies" integratable to the Reusable Launch Vehicle program....

 hypersonic research aircraft; however, drop tests used Balls 8. Orbital Sciences also offer the aircraft for research flights. It is capable of carrying a 23000 kilograms (50,706.3 lb) payload to an altitude of 12800 metres (41,994.8 ft).

Pegasus launches using Stargazer are usually conducted from 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 ....

. However, launches have also been conducted from 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...

, Wallops Flight Facility

Wallops Flight Facility

Wallops Flight Facility , located on the Eastern Shore of Virginia, is operated by NASA’s Goddard Space Flight Center, primarily as a rocket launch site to support science and exploration missions for NASA and other U.S. government agencies...

, and from launch sites outside the United States: Kwajalein Atoll in the Marshall Islands

Marshall Islands

The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

 and Gando Airport in Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

.