下面一起来了解一下这架世界上最大的运输机：
GIGANTIC
身形巨大
The Stratolaunch aircraft is enormous, with a wingspan totaling 385 feet (117 meters), longer than the wingspan of any other aircraft and greater than the length of an American football field.
平流层发射飞机身形巨大，翼展总长为117米，超过所有飞机的翼展，比一个美式足球场还要长。
Among commonly seen aircraft, the double-decker Airbus A380's wings span 262 feet (nearly 80 meters).
在常见的飞机中，双层客机空客A380的翼展近80米。
WEIGHT AND POWER
重量和动力
The Stratolaunch aircraft weighs 500,000 pounds (226,799 kilograms) empty, can carry 250,000 pounds (113,399 kilograms) of fuel, and with payload can take off at a maximum weight of 1.3 million pounds (589,676 kilograms).
平流层发射飞机净重约227吨，可搭载约113吨燃料，最大有效载荷近590吨。
It is powered by six engines of the same type used by Boeing 747s.
它由6台波音747所用的同款发动机提供动力。
AIR LAUNCH
空中发射
On launch missions, Stratolaunch will carry as many as three rockets attached to the center of the wing between the two fuselages. The rockets will be released, ignite their engines and carry small satellites weighing up to 1,000 pounds (453.6 kilograms) to low Earth orbit.
在执行发射任务时，平流层发射飞机可在双机身中间、机翼中心位置搭载多达3枚火箭。飞机可以让火箭点火、发射，将其携带的重达454公斤的小型卫星送入近地轨道。
According to Stratolaunch, the advantages of its system include being able to use numerous airports and avoid the limitations of fixed launch sites which can be impacted by weather, air traffic and ship traffic on ocean ranges.
据平流层发射系统公司介绍，这套系统的优势在于能适应众多机场，固定发射场所可能会受到天气、空中交通状况以及海上船运状况的影响，而平流层发射系统能避免这些限制。
HISTORY
历史回顾
Airborne launches date back decades, most famously to the X-15 program of the 1950s and '60s, when manned rocket planes were carried aloft under the wing of a B-52 bomber and released on hypersonic research flights.
机载发射可以追溯至几十年前，最著名的是上世纪50、60年代的X-15计划，当时一架B-52轰炸机的机翼下搭载了载人火箭飞机，并在超音速飞行的测试研究飞行器上发射。
In the 1990s, Orbital Sciences Corp. (now Orbital ATK) began releasing rockets from the belly of a converted L-1011 airliner to put small satellites into low Earth orbit.
上世纪90年代，轨道科学公司（现为轨道ATK公司）从一架改装的L-1011客机的机身下发射火箭，将小型卫星送入近地轨道。
More recently, Paul Allen, the Microsoft co-founder, funded development of the Burt Rutan-designed SpaceShipOne, the first privately developed manned spacecraft.
再之后，微软公司的联合创始人保罗•艾伦投资研发了伯特•鲁坦设计的“太空飞船一号”。这是第一架私人研发的载人航天器。
Suspended between the twin-fuselages of a special jet, SpaceShipOne was carried to high altitude and released. It reached space on three suborbital flights in 2004.
“太空飞船一号”由一架特制的双机身喷气飞机悬挂在机身中间，将其载入高空并发射。2004年，“太空飞船一号”经过3次亚轨道飞行进入太空。
The same launch concept is being used for SpaceShipTwo, the passenger-carrying craft being developed for Sir Richard Branson's Virgin Galactic space tourism enterprise.
“太空飞船二号”应用了相同的概念，这架载人飞行器是为理查德•布兰森爵士的维珍银河太空旅游公司研发的。
WHAT'S NEXT
下一步会怎样
Initial testing will focus on filling the six fuel tanks to ensure they are properly sealed and that related mechanisms are operating properly.
首轮测试将对机上的6个油箱进行加油测试，检查其密封是否完好，以及相关机械的运行是否正常。
The aircraft will then be taken back inside the hangar for weight and balance testing. Ground testing will lead to flight operations and the first launch demonstration, which is expected in 2019.
随后，飞机将被拖回机库进行重量和平衡性测试，并有望在2019年进行陆地测试，进行飞行操作和首次发射展示。