神舟八号飞船

神八的对接装置与空间站俄罗斯舱段的对接装置直径上相同，但不兼容

China Out Front With Human Lunar Planning


Oct 16, 2009
  
Frank Morring, Jr. and Bradley Perrett/Daejeon, South Korea

Previously circumspect, Chinese space officials are out front now about their interest in sending their astronauts to the Moon on their own, even as they worked the halls of the International Astronautical Congress (IAC) here to establish closer outside links for human-spaceflight cooperation.

Dong Nengli of China’s Manned Space Engineering Program says his organization—which developed the Shenzhou human spacecraft and is planning an unpiloted orbital rendezvous and docking experiment in 2011—is already looking beyond the planned deployment of a 60-ton Chinese station in 2020.

“During the course of the third step of the China manned-spaceflight program, we will conduct a manned lunar mission conception study, validate the key technologies and finally pave the way for manned lunar exploration,” Dong told a press conference on his country’s space program on Oct. 15.

Chinese officials stress that there has been no government approval for a manned lunar landing, and they say China would “welcome” a chance to join the larger international exploration effort that has coalesced around the International Space Station.

“If the Americans and the International Space Station [partners] put forward this kind of cooperation suggestion, we would definitely really welcome these suggestions,” says Wang Jongqui, deputy chief designer of the Manned Space Engineering Program. “We would seriously take that into consideration.”

To that end, Wang and his delegation—which included Chinese spacewalker Zhai Zhigang—met with representatives of the French and German national delegations to the congress here. Their presence at the IAC marks a change in the public face of China’s space program, which in the past has sent representatives of the civilian China National Space Agency (CNSA) to the annual event.

This year, CNSA Administrator Sun Laiyan, a regular at past IAC heads-of-agency plenary sessions, withdrew from the congress after the programs had been printed. Officials of two different Western space agencies say there have been indications the CNSA is on the outs in Beijing, while the head of the Manned Space Engineering Office—Wang Wenbao—told Aviation Week and a delegation from the Space Foundation on Sept. 22 that his organization is handling human spaceflight for the central government (AW&ST Sept. 28, p. 24).

The management-level Manned Space Engineering Office and the Manned Space Engineering Program, which handles the technical side of the human-spaceflight effort, draw their funding from the Chinese military. All of the nation’s astronauts are military pilots; but like their counterparts from the U.S. and Russia, they do not wear their uniforms at international gatherings such as the IAC, and program officials downplay the military link when questioned about it.

Dong and other officials here offered no details about the human lunar concept study, which has been mentioned in Chinese-language technical publications but not announced at an international forum before. Instead, they elaborated on plans to continue gaining spaceflight experience by building toward the 60-ton, three-person space station and to follow up the second Chang’e lunar orbiter—which is set for launch next year—with a robotic lander, rover and eventually a sample-return mission.

The first miniature space station, Tiangong 1, is under construction and still scheduled to go into orbit in 2011 to serve as a docking target for the Shenzhou 8 spacecraft, which will be unmanned. If that goes well, China will move into a series of manned rendezvous and docking tests with Tiangong 1. Wang says there will be two or three Tiangongs, which officials previously said will weigh 8.5 tons. A Tiangong will be set up as a space laboratory in 2013. Astronauts will use it to practice medium-term stays in orbit and to perform scientific experiments. “By operating the space laboratory, China will accumulate experience in building, managing and operating the future space station,” says Dong.

Since China’s upcoming heavy-lift launcher, the Long March 5, will not go into service until 2014, the laboratory’s mass will be limited by the throwweight of the current Long March series, the most powerful of which can lift 13 tons to low orbit.

A robotic cargo craft also is planned to resupply the larger space station, and Wang says it will be structurally related to the Tiangong series.

The docking port China is developing for the Shenzhou 8 mission is similar in diameter to, but not compatible with, the Russian-designed system used on the ISS, Wang says. However, China would be interested in hearing any suggestions that could lead to an international docking-interface standard, he notes.

A concept plan has been finished for the 60-ton space station, which would follow around 2020 (the previous target was “by 2020”). It will be assembled in orbit from three modules, matched to the capability of the Long March 5 and launch from the low-latitude site under construction on Hainan Island. China has said at least one of the station modules will weigh 20 tons; the others are likely to be close to that. Designed to sustain a crew of three for long-duration missions, the station would orbit at an altitude of 400-450 km. (248-280 mi.) and an inclination of 42-43 deg, with a planned service life of 10 years.

The ISS, with a mass of about 300 tons, generally orbits at an altitude less than 400 km. and at an inclination of 51.6 deg., with accommodation for six. It began service in 2000 and—if the recommendations of the Augustine panel reviewing the future of U.S. human spaceflight are followed—would be shut down in 2020, just as the Chinese station becomes operational.

While China builds up experience with human spaceflight in low orbit, it will continue sending robotic probes to the Moon before bringing the two strands together with a possible manned landing. The next lunar mission will be Chang’e 2, due to be launched next October, following the successful Chang’e 1 mission of 2008-09. The Chang’e 2 probe was previously a backup for its predecessor and will orbit the Moon at an altitude of 100 km. Its equipment will include a camera with a resolution of better than 10 meters (33 ft.).

Chang’e 3 will land on the Moon, executing the second phase of the robotic lunar exploration plan. The 3,750-kg. (8,250-lb.) spacecraft is due to be launched in 2012 directly to the Moon without first orbiting the Earth, inserted into a 100 X 100-km. orbit that will be adjusted to 100 X 15 km. When the vehicle reaches the 15-km. perigee, its engine will begin reducing its velocity from 1.7 km./sec. to about zero, turning it to a vertical attitude before the craft reaches an altitude of 2 km. The lander will hover at 100 meters, moving horizontally to avoid any hazards, and then slowly descend to 4 meters, at which point its engine will shut down for a free fall to the surface.

The lander will carry a rover. The scientific objectives include investigating the geological structure of the Moon, its material composition, internal structure and usable materials, and “to build up an observatory” based on the Moon. A later mission “before 2017” will be aimed at bringing lunar samples back to Earth.

China is also looking at sending a probe to Mars, using the experience and infrastructure developed with the Chang’e missions.

神舟的对接装置应该是APAS-89，ISS上PMA使用的是APAS-75，印象中APAS-75的接口可以用来对接APAS-89的主动端
PS：俄国舱段用的不是APAS，所以如果进行对接也是在PMA2或3

如果不谈交会过程，包括对接最后阶段所需的雷达、导航、通信、控制、推进、以及灯光等系统，实际使用过的对接装置基本上有以下两类：

1 “探针-锥”式。主动方有一个探针，被动方是一个内锥，接近时探针进入内锥，探针接触内锥壁后在其引导下移动到中央，内锥中央的装置和探针接触后锁定并实施拉紧操作，最后在周边进行最后锁定。早期的“探针-锥”式（如联盟10号前）是没有内通道的。宇航员必须通过太空步行从一个航天器转移到另一个航天器。美国早期飞船和大部分联盟号使用的是带内通道的“探针-锥”式对接装置。这种装置探针和内锥都安装在可以向内开的“门”上。当对接成功周边锁定后，探针和锥解锁，中间区域增压，气压平衡后两扇门向后打开就形成一个内通道。

2 “异体同构式”。又叫“雌雄同体式”，也有人通俗地叫它“爪式”。它的特点是主动方和被动方使用安全一样的装置。它的对接装置（主要特征是三片梯形的 “爪”）完全安装在周边，这样就留出了内通道的位置。对接时，三片爪进入对方三片爪的空档，倾斜的爪边缘互相接触后可以引导航天器移到正确的位置，然后相互锁定，气压平衡后，打开门就行了。实际使用过的“爪式”有两种型号：APAS-75和APAS-89。前者是75年联盟-阿波罗对接时使用的。后者用于和平号和航天飞机对接，以及国际空间站美国段。APAS-75是美俄联合研制，APAS-89是俄罗斯研制。两者最大的差别是APAS-75的爪向外翻，而APAS-89的爪向内翻。APAS-89的通道尺寸更大。从中国已经发表的未来神舟和空间实验室图片看，中国也会用这类对接装置，但是否和APAS- 75或APAS-89兼容还不清楚，虽然逻辑上使用APAS-89是很合理的。

顺便列一下国际空间站上的对接口：

目前可以使用的对接口： - 星辰舱尾部：用于对接联盟、进步和ATV（探针-锥式） - 曙光舱侧面（指向地球）：用于对接联盟和进步（探针-锥式） - 星辰舱侧面（指向地球反向）：预留以后将Pirs舱移过来以连接“科学平台”太阳电池系统（探针-锥式） - Pirs舱头部（指向地球）：用于对接联盟和进步（探针-锥式） - PMA2联结段（后连命运舱前端）：用于对接航天飞机（APAS-89） - PMA3联结段（后连团结舱侧面）：可用于对接航天飞机，但目前不用（APAS-89） - 团结舱侧面（指向地球）：用于对接临时货运舱（简易口）

曾经可以用来对接运输航天器，但已被舱段连结占用的对接口： - 曙光舱尾部：目前对接星辰舱（探针-锥式） - 星辰舱侧面（指向地球）：目前对接Pirs舱（探针-锥式） - 曙光舱头部：目前对接PMA1连结段（APAS-89） - PMA1联结段（后连团结舱尾部）：目前对接曙光舱（APAS-89）

舱段之间简易对接口（不具备自主对接功能，只能在机械臂帮助下对接）： - PMA1和团结舱之间 - PMA3和团结舱之间 - PMA2和命运舱之间 - 命运舱和团结舱之间 - Z1桁架和团结舱之间 - Quest舱和团结舱之间

空间对接机构综述 :空间对接技术和对接机构已经成为航天技术的一个重要方向，是载人飞行的关键技术，也是今后扩展卫星应用能力的 一个重要手段。

            前言

    对接机构最早是用来进行载人飞行技术的重要部分，实现飞行器之间(如飞船、航天飞机、空间站等)在宇宙空间的连接，航天员可以从一个飞行器转移到另一个飞行器。例如苏联／俄罗斯空间站飞行中，航天员利用飞船与空间站对接进入空间站；还有美国登月飞行中，航天员利用登月舱与"阿波罗"飞船对接进入飞船等。对接技术和对接机构是载人飞行技术发展的关键技术。

    由于运载能力的限制，大型空间建筑无法一次发射升空，利用对接技术，可以在空间装配大型空间站、进行复杂空间作业。如"和平号"空间站是由六个模块舱在空间对接而成，正在建造的国际交间站则将对接装配成400吨的空间庞然大物。通过航天器的在轨装配(对接)，可以克服运载器运输能力的限制，大大扩展人类空间活动的范围和规模。

    近年来对接机构的应用又有了新的发展方向、卫星等无人飞行器也开始进行对接研究，并取得很大成果。

            对接机构的发展历程

    空间交会对接技术得到了迅速发展和厂泛应用。并且已成为世界航天业的发展热点，不少国家都把交会对接技术作为空间技术发展的重要课题加以研究。空间对接技术的研究升始于20世纪60年代初期、1963年3月，美国"双子星座"载人飞船的"阿金娜"火箭在宇航员的参与下实现了人类历史上首次空间对接。 1967年10月，苏联发射的“宇宙-186”和"宇宙-188"两个无人航天器首次实现了空间自动交会对接。随着，美国在登月计划中，苏联／俄罗斯在空间站飞行中大量进行对接作业、包括目前正在进行组装的国际空间站。迄今为止，俄罗斯和美国共成功进行了200多次空间交会对接活动。

    20世纪80年代，欧空局和日本也积极开展了各自的空间交会对接研究，日本已于1998年成功地进行了航天器的空间交会对接飞行试验。欧空局和日本把研究的重点均放在发展空间无人自动交会对接技术上。这种对接技术对控制系统的要求很高，但可以实现碰撞载荷很小的软对接。

            典型对接机构

    "锥-杆"式对接机构是苏联／俄罗斯最早的对接机构，出现在1967年苏联对这种机构进行了不断的改进，研制成用于载人飞船、载货飞船以及空间站模块舱与空间站对接的"锥-杆"式对接机构。这种对接机构在主动对接机构的通道盖上装有能够伸缩的传功机构，被动对接机构的盖子本身就是接纳锥，主动部件带对接框的密封壳体与被动部件密封壳体可形成过渡通道。"锥-杆"式对接机构结构简单，重量轻，被大量使用。但是在应用中需要主、被动两种机构成对使用，通用性差。

    异体同构周边式对接机构(APAS)最初是由美国和苏联专家共同研制成功的。它的主要优点是：追踪飞行器和目标飞行器采用构型完全一样的对接机构，因此无主动和被动之分；另外对接机构的所有部件均放置在周边而将航天器的中心位置留出来作为过渡通道。这种机构有带三个导向片的对接环，和并联式的差动缓冲机构，通过装在导向片上的三个捕获锁实现捕获，密封连接用对接框和对接锁完成，对接处的密封由两个彼此接触的橡胶密封圈来保证。

    在"联盟号"的APAS中，俄罗斯发展了"差动式机电缓冲阻尼系统"，在此基础上研制了用于国际空间站的APAS-89式对接机构，已经用于国际空间站的装配和航天飞机的对接。

    研制卫星用对接机构，目的是使卫星应尽可能长时间的维持有效和稳定的运动轨道，以延长在轨寿命，降低更替频率。同时，卫星需要具备变轨能力以使其不易受到攻击，能够为观察新的敏感地区重新定位，或减少对全球覆盖多卫星群的需求。此外，由于发射成本及重量所限，要求卫星具有在轨服务功能，完成在轨燃料加注，利用自动负载处理系统更换卫星受损元件或补充耗费品等任务。卫星用对接机构将大大扩展卫星的应用范围和使用灵活性。

    目前世界各国部在积极开展这项工作。日本的ETS-VII卫星所采用的软撞击对接机构已经进行了飞行试验，MicroSats小卫星交会对接机构，用于轨道快车计划的A5DS的对接机构和COMET自功交会对接试验在研制过程当中。

            对接机构的关键技术

    对接机构在我国是全新的技术，其中有许多问题是以前从未碰到的。由于对接过程是碰撞和机构运动的复合过程，需要综合考虑对接机构的力学参数和结构布局等参数；要研究符合动力学参数的设计方法和修正调整方案；考虑在温度、真空等空间环境影响和加工精度等因素下，对接机构的精度设计、分配和保证。需要开展对接碰撞及机构动力学仿真技术的研究，对接碰撞问题的精确求解理论上还在研究之中；复杂机构的动力学模型的精度难以保证、数值计算结果误差较大；机构的摩擦、润滑、间隙、温度的影响、局部碰掩等建立模型问题。在地面进行对接机构模拟失重条件下的对接动力学过程试验，和高低温等环境条件下的对接试验也有很大难度。

            结束语

    空间对接已经成为航天事业继续发展的一个重要的支撑性技术。随着我国载人航天工程的进展。我国的空间对接技术的研究已迫在眉睫。

“天宫一号”将升级改造成货运飞船。货运飞船既具有交会对接功能，也具备燃料补充功能，可以对空间站在空间进行燃料补充。货运飞船的第一次发射将在海南文昌航天发射场进行。

根据公开图片测算，天宫一号目标飞行器的实验舱直径3米多，除去内部实验设备后改做货运飞船，足够容纳5.5吨货物，而飞船总重也将达到13吨，符合未来液氧煤油火箭CZ—2F/H的运载能力。
按戚老的说法，天宫一号和二号都是8吨多，天宫三号较大而重，具有生命维持保障系统。天宫一号目标飞行器实验舱（及未来货运飞船货舱）可以看作是现有神舟飞船轨道舱的成比例放大。天宫一号目标飞行器（及未来货运飞船）的推进舱由现有神舟飞船的推进舱稍作改动而来，直径都是2.5米，尺寸几乎相同。

补充修正一下，天宫一号推进舱呈圆柱状，尾段不扩宽，直径可能是2.8米（即神舟飞船推进舱的尾段直径），按此推算实验舱直径约3.5米。