''Stargazer'' is a Lockheed L-1011 TriStar built in 1974, that was modified in 1994 for use by

Orbital Sciences Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other governmen ...

(now part of

Northrop Grumman Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military techn ...

) as a

mother ship A mother ship, mothership or mother-ship is a large vehicle that leads, serves, or carries other smaller vehicles. A mother ship may be a maritime ship, aircraft, or spacecraft. Examples include bombers converted to carry experimental airc ...

launch pad A launch pad is an above-ground facility from which a rocket-powered missile or space vehicle is vertically launched. The term ''launch pad'' can be used to describe just the central launch platform ( mobile launcher platform), or the entir ...

for the Pegasus launch vehicle. , 45 rockets (containing nearly 100 satellites) have been launched from it, using the Pegasus-H and Pegasus-XL configurations. As of 2019, ''Stargazer'' is the only L-1011 airframe still airworthy.

History

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

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

-operated

Boeing The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and p ...

NB-52B

Balls 8 ''Balls 8'' is a NASA Boeing NB-52B mothership which was retired in 2004 after almost 50 years of flying service with NASA. The aircraft is famous for dropping the X-15 aerospace research vehicle on 106 of the 199 X-15 program flights. His ...

, 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. Stargazer was also used for captive tests and transportation of the

X-34 The Orbital Sciences X-34 was intended to be a low-cost testbed for demonstrating "key technologies" that could be integrated into the Reusable Launch Vehicle program. It was intended to be an autonomous pilotless craft powered by a " Fastrac" li ...

hypersonic research aircraft; however,

drop test A drop test is a method of testing the in-flight characteristics of prototype or experimental aircraft and spacecraft by raising the test vehicle to a specific altitude and then releasing it. Test flights involving powered aircraft, particularly ...

s used

also offer the aircraft for research flights. It is capable of carrying a payload to an altitude of . Stargazer on IRIS mission,

Pegasus launches using Stargazer are usually conducted from

Vandenberg Air Force Base Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida * Vandenberg Sp ...

. Launches have also been conducted from the

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the statio ...

, the

Kennedy Space Center The John F. Kennedy Space Center (KSC, originally known as the NASA Launch Operations Center), located on Merritt Island, Florida, is one of the National Aeronautics and Space Administration's (NASA) ten field centers. Since December 1968 ...

, the

Wallops Flight Facility and from launch sites outside the US: Kwajalein Atoll in the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Intern ...

and Gando Airport in

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

. In 2010, Stargazer was reengined with -thrust Rolls-Royce RB211-524B4 turbofans to replace its original -thrust RB211-22Bs. In 2015, Stargazer was repainted to reflect Orbital Sciences' merger with Alliant Techsystems. On 15 December 2016, Stargazer successfully launched CYGNSS on behalf of NASA on its second attempt. The first attempt on 12 December was scrubbed due to issues with the hydraulic system responsible for separating the Pegasus rocket from the launch aircraft. Stargazer appeared in

livery in 2018 following the acquisition of Orbital ATK. Stargazer launched the

Ionospheric Connection Explorer Ionospheric Connection Explorer (ICON) is a satellite designed to investigate changes in the ionosphere of Earth, the dynamic region high in our atmosphere where terrestrial weather from below meets space weather from above. ICON studies the i ...

on 11 October 2019. The launch was originally scheduled for June 2017 but was scrubbed when an anomalous piece of vehicle data was observed during a ferry flight. The data was related to the rudder position of the

Pegasus XL Pegasus is an Air launch to orbit, air-launched launch vehicle developed by Orbital Sciences Corporation (OSC) and now built and launched by Northrop Grumman. Capable of carrying small payloads of up to into low Earth orbit, Pegasus first fl ...

rocket and was observed during a routine in-flight vehicle health check. The launch was delayed multiple times from 2017 to 2019, finally occurring October 11, 2019.

Background

The Lockheed L-1011 TriStar carrier aircraft first flew in February 1974, and was delivered to

Air Canada Air Canada is the flag carrier and the largest airline of Canada by the size and passengers carried. Air Canada maintains its headquarters in the borough of Saint-Laurent, Montreal, Quebec. The airline, founded in 1937, provides scheduled an ...

as C-FTNJ the following month. In May 1992 Orbital Sciences acquired the plane and had

Marshall Aerospace Marshall Group, formerly Marshall of Cambridge and Marshall Aerospace and Defence Group, is a British company headquartered in Cambridge, United Kingdom. Subsidiaries include Marshall Aerospace, an aircraft maintenance, modification, and desig ...

in the UK implement accommodations for the Pegasus system. It was renamed for use as carrier aircraft for the Pegasus launch system. The company also considered other aircraft including the

Boeing B-52G Stratofortress The Boeing B-52 Stratofortress is an American long-range, subsonic, jet-powered strategic bomber. The B-52 was designed and built by Boeing, which has continued to provide support and upgrades. It has been operated by the United States Air ...

, Boeing 747, and

DC-10 The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas. The DC-10 was intended to succeed the DC-8 for long-range flights. It first flew on August 29, 1970; it was introduced on August 5, 19 ...

, considering altitude and speed performance, range, modification complexity, as well as acquisition and operational costs.

References

{{reflist United States special-purpose aircraft Lockheed aircraft Individual aircraft Rocket launch sites Orbital Sciences Corporation Aircraft related to spaceflight

History

Background

See also

References