|
|family=Shuttle-Derived Launch Vehicles |derivatives= |comparable= |status= Undergoing development |sites=LC-39B, Kennedy Space Center |launches= |success= |fail= |partial= |other_outcome= |first= No later than November 2018〔 |only= |payloads=Orion MPCV, Europa Multiple-Flyby Mission, Uranus orbiter and probe |stagedata= }} The Space Launch System (SLS) is an American Space Shuttle-derived heavy expendable launch vehicle being designed by NASA. It follows the cancellation of the Constellation program, and is to replace the retired Space Shuttle. The NASA Authorization Act of 2010 envisions the transformation of the Constellation program's Ares I and Ares V vehicle designs into a single launch vehicle usable for both crew and cargo, similar to the Ares IV. SLS will be the world's most powerful rocket with 20% more thrust than Saturn V and a comparable payload capacity.〔〔http://www.gizmag.com/nasa-space-launch-system-sls-critical-design-review/38612/〕〔http://www.space.com/12954-nasa-rocket-powerful-space-launch-system.html〕 The SLS launch vehicle is to be upgraded over time with more powerful versions. Its initial Block 1 version is to lift a payload of 70 metric tons to low Earth orbit (LEO), which will be increased with the debut of Block 1B and the Exploration Upper Stage.〔(【引用サイトリンク】title=Space Launch System )〕 Block 2 will replace the initial Shuttle-derived boosters with advanced boosters and is planned to have a LEO capability of more than 130 metric tons to meet the congressional requirement.〔 These upgrades will allow the SLS to lift astronauts and hardware to various beyond-LEO destinations: on a circumlunar trajectory as part of Exploration Mission 1 with Block 1, to a near-Earth asteroid in Exploration Mission 2 with Block 1B, and to Mars with Block 2. The SLS will launch the Orion Crew and Service Module and may support trips to the International Space Station if necessary. SLS will use the ground operations and launch facilities at NASA's Kennedy Space Center, Florida. During the joint Senate-NASA presentation in September 2011, it was stated that the SLS program has a projected development cost of $18 billion through 2017, with $10 billion for the SLS rocket, $6 billion for the Orion Multi-Purpose Crew Vehicle and $2 billion for upgrades to the launch pad and other facilities at Kennedy Space Center.〔 ==Design and development== On September 14, 2011, NASA announced its design selection for the new launch system, declaring that it, in combination with the Orion spacecraft, would take the agency's astronauts farther into space than ever before and provide the cornerstone for future US human space exploration efforts. Three versions of the launch vehicle are planned: Block 1, Block 1B, and Block 2. Each will use the same core stage with four main engines, but Block 1B will feature a more powerful second stage called the Exploration Upper Stage (EUS), and Block 2 will combine the EUS with upgraded boosters. Block 1 has a baseline LEO payload capacity of and Block 1B has a baseline of . The proposed Block 2 will have lift capacity of , which is similar to that of the Saturn V. Some sources state this would make the SLS the most capable heavy lift vehicle built;〔 although the Saturn V lifted approximately 140 metric tons to LEO in the Apollo 17 mission.〔(The Congress of the United States. Congressional Budget Office, October 2006, pp. X,1,4,9. ) "The Apollo Saturn V launch vehicle had a lift capability of 140 metric tons to low Earth orbit."〕 During the development of the SLS a number of different configurations were considered, including a Block 0 with three main engines,〔 a Block 1A variant which would have upgraded the vehicle's boosters instead of its second stage, and a Block 2 with five main engines and a different second stage, the Earth Departure Stage, with up to three J-2X engines.〔 In February 2015, it was reported that NASA evaluations showed "over performance" versus the baseline payload for Block 1 and Block 1B configurations.〔 On July 31, 2013 the SLS passed the Preliminary Design Review (PDR). The review encompassed all aspects of the SLS' design, not only the rocket and boosters but also ground support and logistical arrangements. On August 7, 2014 the SLS passed a milestone known as Key Decision Point C and entered full-scale development, with an estimated launch date of November 2018. 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「Space Launch System」の詳細全文を読む スポンサード リンク
|