from spacefuture.com 译/卫偲
发展航天事业耗资巨大,但这丝毫没有阻止人类对太空技术的探索与创新。太空技术未来的发展方向不仅是要将宇航员送上天搞科研,而且要将普通人送上天去旅行。为了实现这个目标,胸怀航天梦的科学家与实干家们一直在努力,设计和制造了一系列针对太空旅行的航天器与运载火箭。相信在不久的未来,会有越来越多的普通人飞向太空,感受太空旅行的美妙。
In order for people to be able to travel economically to space, for space tourism and for other purposes, we need reusable launch vehicles. All commercial transport industries use reusable vehicles—and so will the commercial space transport industry. Luckily research aimed at developing low-cost reusable launch vehicles has increased recently. The following is a list of projects under way today.
Winner of the $10m Ansari X-Prize1), this suborbital2) passenger-carrying spaceplane was designed by Burt Rutan3)s Scaled Composites, famous for graphite4) composite and also the integrating contractor for the former Roton5). Following their successful bid6) to win the X-Prize, Scaled Composites are now turning their eyes to the next step: the development of a commercially viable passenger-carrying suborbital space vehicle.
SpaceShipOne features a rubber-nitrous oxide7) hybrid rocket engine and cold gas attitude8) control thrusters9); a graphite/epoxy10) primary structure; 3-place, sea-level, shirt-sleeve cabin environment; a low maintenance thermal protection system; and a unique feathered reentry system.
The spaceplane is carried under the belly of Scaled Composites White Knight carrier aircraft. The White Knight is a piloted, twin-turbojet11) research aircraft derived from the Proteus12) intended for high-altitude missions. Its first flight was on August 1, 2002. It provides a high-altitude airborne launch of SpaceShipOne. The White Knight is also equipped to flight-qualify13) all the SpaceShipOne systems except rocket propulsion. The aircrafts cockpit14), avionics15), life support systems, pneumatics16), trim servos, data system and electrical system components are identical to those installed in SpaceShipOne.
A passenger-carrying reusable SSTO17) VTOL18) rocket designed to carry 50 passengers to 200 km Earth orbit started as part of a study program by the Japanese Rocket Society. Since none of the space agencies of the world were studying how to make launch services available to the general public, the JRS started a Space Tourism Study Program in 1993, with the objective of getting the price of a flight to orbit down to around $10,000 per passenger. Work on Kankoh-maru has grown steadily in depth and breadth ever since, and has helped to accelerate the acceptance of space tourism as the direction for space development work today.
Spacebus is a design for a 2-stage passenger-carrying HTOL19) spaceplane by the company Bristol Spaceplanes in Britain. The first stage uses jet engines for take-off, followed by rocket engines to climb to high altitude for separation, after which the upper stage uses rocket engines to reach orbit. Using existing jet and rocket engines is very attractive in reducing initial development costs. And though new air-breathing rocket engines might be more efficient, theyre not needed initially.
Spacecab is a scaled-down version of Spacebus designed to carry 6 passengers. Its attractive as a first step to HTOL launch services since it uses only existing technology, and could start passenger operations much earlier than a vehicle requiring new engines to be developed.
SpaceXs Dragon is a small orbital spacecraft designed for transporting people and goods to and from the ISS20). It has two configurations21): an unmanned cargo configuration and a crew/passenger configuration capable of transporting up to seven people. It is built by a consortium22) led by SpaceX under NASAs Commercial Orbital Transportation Services (COTS) initiative. Dragon is also equipped with an ISS-compatible dock23) that is exposed through a removable nosecone24). Return to the Earths surface is achieved through a parachute-assisted splashdown25) and recovery.
Dragon is delivered into orbit on top of the Falcon 9 two-stage launch vehicle, an expanded version of the Falcon 1 rocket that completed a successful test launch to orbit on 28 September 2008 (after three prior failures). Both stages of the Falcon 9 are intended to be reusable.
The intended use for the combined vehicle is primarily to serve as a replacement for the shuttle fleet after their retirement, so space tourism is not an overt goal. Unlike vehicles aimed explicitly at the space tourism market, the Dragon/Falcon 9 combination is not fully reusable, and so is unlikely to withstand competition from a fully reusable orbital vehicle. However, until such time as such vehicles become available it may be the first privately financed space vehicle to be capable of delivering people, space tourists or otherwise, to orbit.
Xerus is a two-person reusable spaceplane proposed by XCOR Aerospace, which takes off and lands like a conventional aircraft. It is capable of climbing suborbitally to 100 km using a cluster of reusable rocket engines developed by XCOR. After a short period of weightless free fall the vehicle then re-enters the atmosphere. While the primary market for Xerus is space tourism, the vehicle is also being targeted at microsatellite delivery and suborbital science payloads.
XCORs Lynx, announced in March of 2008, is a follow-on design based on Xerus. Like Xerus, Lynx is a two-person suborbital spaceplane designed for the space tourism market but also aimed at science and research applications.
Thunderbird is a low cost fully reusable VTOL rocket from UK-based Starchaser Industries, which has an established track record26) in unmanned rocketry. It is an X-Prize contender, and is designed to carry three people on short suborbital pleasure flights into space.
The vehicle uses existing off-the-shelf27) components wherever possible to minimize development cost, combined with an advanced composite for the airframe. The primary propulsion is provided by LOX/kerosene engines28) which carry the vehicle to a maximum altitude of 100 km after burnout before re-entering tail-first using a steerable parasail29). Reaction control is handled independently by cold gas thrusters.
The Thunderbird is a single stage vehicle, but composed of two discrete and separable units: a command module, which includes the cabin, life support and reaction control system, and a propulsion module comprising the fuel tanks, engines and landing gear. In an emergency the command module is detachable from the rest of the vehicle, allowing the crew to be brought down independently.
Nova is a scaled-down version of Thunderbird designed to bridge the gap between previously flown unmanned rockets and Thunderbird. Standing at roughly two thirds of the height of its 52 feet larger sibling, Nova is designed to carry a single person into space to a maximum altitude of approximately 100 km. Although not an X-Prize contender due to its less than three-person capacity, Nova is intended to be the worlds first privately developed spaceship.
为了让人们能够以更经济的方式前往太空,进行太空旅行或实现其他目的,我们需要可重复使用的运载器。所有的商业运输行业都使用可重复使用的运输工具,太空商业运输行业也将如此。幸运的是,旨在开发低成本、可重复使用运载器的研究最近已经多了起来。下文列出的就是如今正在开展的一些项目。
这架亚轨道载客航天飞机是奖金数额为一千万美元的安萨里X奖的得主,由伯特·鲁坦的缩尺复合材料公司设计。该公司以石墨复合材料著称,并且是更早的航天器罗顿的集成承包商。在成功赢得了X奖之后,缩尺复合材料公司现在把注意力转向了下一步:开发一架商业上可行的亚轨道载客航天器。
太空船一号的主要特色如下:采用橡胶-氧化亚氮混合火箭发动机和冷气体姿态控制推进器;采用石墨/环氧树脂主结构;座舱可容纳三人,具有海平面气压水平,在舱内只穿衬衣即可;采用低维护热防护系统和独特的羽毛型再入系统。
这架航天飞机搭载于缩尺复合材料公司制造的运载飞机白色骑士的腹下。白色骑士是一架有人驾驶的双涡轮喷气式研究用飞机,其源头可追溯至用于高空飞行任务的海神号飞机。白色骑士的首次飞行是在2002年8月1日。它能使太空船一号实现高空机载发射。白色骑士可以用来对太空船一号除火箭推进系统外的其他所有系统进行飞行资格测试。这架飞机配有与太空船一号完全一样的驾驶员座舱、航空电子设备、生命支持系统、气动装置、平衡伺服系统、数据系统以及电气系统部件。
观光丸是一枚可重复使用的单级入轨垂直起降载客火箭,其设计目的是将50名乘客运载至200千米高度的地球轨道。该火箭最初是日本火箭协会一项研究计划中的一部分。鉴于当时世界上没有一个太空机构在研究如何为普通大众提供发射运载的服务,日本火箭协会于1993年启动了一项太空旅行研究计划,目标是将飞往太空轨道的价格降至每位乘客一万美元左右。自那以后,观光丸的研究工作在深度和广度方面一直得以稳步进展,并且促使人们更快地接受了如下观念:太空旅行是当今太空开发工作的方向。
太空巴士是由英国布里斯托航天飞机公司设计的二级水平起降载客航天飞机。它的第一级采用喷气发动机起飞,然后利用火箭发动机攀升至高空进行分离。之后,上面一级使用火箭发动机进入轨道。使用现有的喷气发动机和火箭发动机非常有吸引力,因为这样能够降低初始开发成本。虽然新型的吸气式火箭发动机可能更有效,但初始阶段并不需要这样的发动机。
太空的士是太空巴士的缩小版,能够携带六名乘客。作为实现水平起降发射服务的第一步,太空的士很有吸引力,因为它仅使用现有技术,与需要开发新发动机的运载器相比,它启动客运业务的时间会提早很多。
太空探索技术公司的天龙号飞船是一种小型轨道航天器,用于向国际空间站往返运送人员和货物。它包括两部分构造:无人驾驶货运构造和运载量可达七人的机组成员/乘客构造。该航天器是由太空探索技术公司牵头的几家企业根据美国航空航天局的商业轨道运输服务(COTS)计划建造的。天龙号在可拆卸的头锥上配备有一个与国际空间站兼容的对接装置。通过降落伞辅助溅落和回收的方式,飞船可返回地球表面。
天龙号飞船搭载在猎鹰9号两级运载器上被送入轨道。猎鹰9号是猎鹰1号火箭的扩大版,猎鹰1号在经历三次失败之后于2008年9月28日成功地完成了发射至轨道的测试。猎鹰9号的两级都采用了可重复使用的设计。
这套组合型运载器的设想用途主要是在美国国家航空航天局的航天飞机退休后担任替补,所以太空旅行显然并不是这一运载器的目标。与明确针对太空旅行市场的运载器不同,天龙号与猎鹰9号的组合并不是能完全重复使用的,所以不大可能与能完全重复使用的轨道运载器进行竞争。然而,在这类运载器投入使用之前,天龙号与猎鹰9号的组合可能是第一个由私人投资的能将人类——太空游客或因其他目的前往太空的人——送入太空轨道的航天器。
齐罗斯是由XCOR宇航公司设计的可重复使用的双人航天飞机,可以像传统飞机一样起飞和降落。它能够利用一组由XCOR设计的可重复使用的火箭发动机攀升至100千米的亚轨道。在短时间的失重状态下自由下落后,这个运载器重新进入大气层。虽然齐罗斯的主要市场是太空旅行,但该运载器也正在把目标指向微卫星发射和亚轨道科学载荷。
XCOR公司于2008年3月对外宣布的山猫航天飞机是基于齐罗斯的后续设计。与齐罗斯一样,山猫也是亚轨道双人航天飞机,是针对太空旅行市场而设计的,但也打算用于科学研究。
雷鸟是英国追星者工业公司生产的一种低成本、可完全重复使用的垂直起降火箭,该公司以往在无人驾驶火箭领域具有良好的表现纪录。雷鸟是X奖的争夺者之一,其设计目的是将三人送入太空的亚轨道进行短暂的休闲飞行。
该运载器尽可能使用现有的非定制组件,以使开发成本降到最低,同时使用了先进的复合材料制作机身。火箭的主推进力由液氧/煤油发动机提供,发动机在燃料耗尽后可将火箭送达100千米的最大高度。之后火箭使用一个可操纵的滑翔伞以尾部先入的方式重返大气层。火箭的反作用力控制则由冷气体推进器独立完成。
雷鸟是一个单级运载器,但包括两个相互分离的独立单元:一个是指挥舱,包括机舱、生命支持系统和反作用力控制系统;另一个是推进舱,包括燃料箱、发动机和降落架。在紧急情况下,指挥舱可以与火箭的其余部分分离,将机组人员独立带回。
新星是雷鸟的缩小版本,旨在弥补以前使用的无人驾驶火箭与雷鸟之间的差距。新星的高度大约是其52英尺高的大个兄弟的三分之二。根据其设计,新星可以将一个人送入太空,飞行的最大高度接近100千米。由于新星的运载量不到三人,所以它无法参与X奖的角逐,但新星的设计目标是要成为世界上第一个私人开发的飞船。
1. Ansari X-Prize: 安萨里X奖,原名为X奖(X Prize),设立于1996年5月,是为促进私人载人航天技术的创新而设立的总额为一千万美元的航天大奖。
2. suborbital [s??b??b?tl] adj. 亚轨道的
3. Burt Rutan:伯特·鲁坦(1943~),美国著名的飞行学家和设计师,太空船一号的设计师,他于1982年创立了缩尺复合材料公司。
4. graphite [?ɡr?fa?t] n. [矿]石墨
5. Roton:罗顿,一款单级入轨、可重复使用和垂直降落的载人航天器,由一家名为“滚动火箭”(Rotary Rocket)的公司设计与制造。该公司后来因为资金短缺于2001年初倒闭。
6. bid [b?d] n. 努力,争取
7. oxide [??ksa?d] n. [化]氧化物
8. attitude [??t?tju?d] n. [空] (飞行时的)姿态
9. thruster [?θr?st?(r)] n. 推进器
10. epoxy [??p?ksi] n. [化]环氧树脂,热固树脂的一种,尤用为表面涂料和黏合剂。
11. turbojet [?t??b??d?et] n. [空]涡轮喷气飞机
12. Proteus:海神号飞机,由缩尺复合材料公司推出的长航时高空飞机
13. flight-qualify:对……进行飞行资格测试,即对某一产品、过程或材料进行测试,从而证明它能够适应太空飞行环境。
14. cockpit [?k?kp?t] n. 驾驶员座舱
15. avionics [?e?vi??n?ks] n. 航空电子设备
16. pneumatic [nju??m?t?k] n. 气体力学设备
17. SSTO:单级入轨,single stage to orbit的缩写
18. VTOL:垂直起飞与着陆,vertical take-off and landing的缩写
19. HTOL:水平起飞与着陆,horizontal take-off and landing的缩写
20. ISS:国际空间站,International Space Station的缩写
21. configuration [k?n?f?ɡ??re??n] n. 构造
22. consortium [k?n?s??ti?m] n. 联营企业,联盟
23. dock [d?k] n. 空间对接
24. nosecone [?n??zk??n] n. (火箭或导弹的)头锥
25. splashdown [?spl??da?n] n. [空] (宇宙飞船的)溅落
26. track record:以往的记录
27. off-the-shelf:(军用产品等)现成的,非专门设计(或定制)的
28. LOX/kerosene engine:液氧/煤油发动机
29. parasail [?p?r?se?l] n. 滑翔伞