Lockheed, once a leading manufacturer of commercial and military transport aircraft, produced the L-1011 TriStar as its most iconic commercial airliner. The TriStar was the third widebody jet to enter service after the Boeing 747 and McDonnell Douglas DC-10. Although it could carry up to 400 passengers and fly over 4,000 nautical miles, financial issues and delays hampered its success. Lockheed ceased production in 1984 after building 250 units and withdrew from the commercial aircraft sector.
Today, only one Lockheed L-1011 TriStar remains operational in the United States. Northrop Grumman operates this aircraft, known as Stargazer, using it as a mothership for launching Pegasus rockets that deploy small satellites into low-Earth orbit. According to Northrop Grumman’s website: "Pegasus is carried aloft by our Stargazer L-1011 aircraft to approximately 40,000 feet over open ocean, where it is released and free-falls for five seconds before igniting its first stage rocket motor." The company adds that "Pegasus has conducted 45 missions, launching almost 100 spacecraft."
Stargazer began service with Air Canada in early 1974 before being acquired by Orbital Sciences in 1992 for conversion into a launch platform. Orbital Sciences evaluated other aircraft types such as the B-52 bomber and Boeing 747 but selected the TriStar for its specific requirements. In 2018, Northrop Grumman acquired Orbital Sciences.