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| height = (Pegasus) (Pegasus XL) | diameter = | mass = (Pegasus) (Pegasus XL) | stages = 3 | status = Active | sites = Air launch to orbit | launches = 42 | success = 37 | fail = 3 | partial = 2 | other_outcome = | first = Pegsat / NavySat 1990-04-05 19:10:17 UTC | last = | payloads = |family = Air launch to orbit |derivatives = |comparable = }} The Pegasus is an air-launched rocket developed by Orbital ATK, formerly Orbital Sciences Corporation. Capable of carrying small payloads of up to into low Earth orbit, Pegasus first flew in 1990 and remains active . The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage. Pegasus is released from its carrier aircraft at approximately , and its first stage has wings and a tail to provide lift and attitude control while in the atmosphere. == Pegasus program == The Pegasus's three Orion solid motors were developed by Hercules Aerospace (now Alliant Techsystems) specifically for the Pegasus launcher. Additionally, wing and tail assemblies and a payload fairing were developed. Most of the Pegasus was designed by a team led by Dr. Antonio Elias. The wing was designed by Burt Rutan. * Mass: 18,500 kg (Pegasus), 23,130 kg (Pegasus XL) * Length: 16.9 m (Pegasus), 17.6 m (Pegasus XL) * Diameter: 1.27 m * Wing span: 6.7 m * Payload: 443 kg (1.18 m diameter, 2.13 m length) Orbital's internal projects, the Orbcomm communications constellation and the OrbView observation satellites, plus Orbcomm-derived satellites (the "Microstar" platform) served as guaranteed customers and additional seed money. Soon after development began, several government and military orders were placed, as the Scout launcher was slated for phaseout. The first successful Pegasus launch occurred on April 5, 1990 with NASA test pilot and former astronaut Gordon Fullerton in command of the carrier aircraft. Initially, a NASA-owned B-52 Stratofortress NB-008 served as the carrier aircraft. By 1994, Orbital had transitioned to their "Stargazer" L-1011, a converted airliner which was formerly owned by Air Canada. The name "Stargazer" is an homage to the television series ''Star Trek: The Next Generation'', the character Jean-Luc Picard was captain of a ship named ''Stargazer'' prior to the events of the series, and his first officer William Riker once served aboard a ship named ''Pegasus''.〔(【引用サイトリンク】url=http://www.startrek.com/database_article/pegasus-the )〕 The Pegasus XL, introduced in 1994 has lengthened stages to increase payload performance. In the Pegasus XL, the first and second stages are lengthened into the Orion 50SXL and Orion 50XL, respectively. Higher stages are unchanged; flight operations are similar. The wing is strengthened slightly to handle the higher weight. The standard Pegasus has been discontinued; the Pegasus XL is still being produced. Pegasus has flown 40 missions in both configurations as of October 19, 2008 〔(【引用サイトリンク】 title=Pegasus Mission History )〕 and two more after that. Of these, 35 were considered successful launches plus the two launches after that. Dual payloads can be launched, with a canister that encloses the lower spacecraft and mounts the upper spacecraft. The upper spacecraft deploys, the canister opens, then the lower spacecraft separates from the third-stage adapter. Since the fairing is unchanged for cost and aerodynamic reasons, each of the two payloads must be relatively compact. For their work in developing the rocket, the Pegasus team led by Dr. Antonio Elias was awarded the 1991 National Medal of Technology by U.S. President George H. W. Bush. The initial launch price offered was US$6 million, without options or a HAPS (Hydrazine Auxiliary Propulsion System) maneuvering stage. With the enlargement to Pegasus XL and the associated improvements to the vehicle, baseline prices increased. In addition, customers usually purchase additional services, such as extra testing, design and analysis, and launch-site support. As of 2015, the most recent Pegasus XL to be purchased--a planned June 2017 launch of NASA's Ionospheric Connection Explorer mission--had a total cost of $56.3 million, which NASA notes includes "firm-fixed launch service costs, spacecraft processing, payload integration, tracking, data and telemetry and other launch support requirements."〔(【引用サイトリンク】 title=NASA Awards Launch Services Contract for Ionospheric Connection Explorer )〕 For many small satellites it is desirable to be the primary payload and be placed into the orbit desired, as opposed to being a secondary payload placed in a compromise orbit. For example, Pegasus launches from equatorial launch sites can put spacecraft in orbits avoiding the South Atlantic Anomaly (a high radiation region over the South Atlantic ocean) which is desirable for many scientific spacecraft. Though more expensive than satellites launched as secondary cargoes on larger launchers, Pegasus offers these benefits. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pegasus (rocket)」の詳細全文を読む スポンサード リンク
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