中國載人航天新聞發言人武平昨 (28) 日在酒泉衛星發射基地正式宣佈，中國首次太空交會對接任務將於 9 月底至 11 月中旬，相繼發射「天宮一號」目標飛行器和「神舟八號」飛船。「天宮一號」將於今 (29) 日晚上 9 時 16 分至 31 分擇機發射，並與隨後升空的「神八」飛船進行兩次交會對接。任務完成後，「神八」飛船將返回地面，「天宮一號」則會轉入長期運行管理模式，等待下次交會對接。武平表示，「天宮一號」飛行的主要任務是，為實施太空交會對接試驗提供目標飛行器；初步建立長期無人在軌運行、短期有人照料的載人太空試驗平台，為太空站研製積累經驗；進行太空科學實驗、航天醫學實驗和太空技術試驗。據悉，「天宮一號」升空後，將經兩次變軌進入高度約為 350 公里的近圓軌道，進行在軌測試。「神八」飛船發射前，「天宮一號」降軌至高度約 343 公里的近圓軌道，等待交會對接。「神舟八號」飛船發射入軌後兩天內，完成與「天宮一號」的第一次交會對接，形成組合體。組合體飛行12天左右，擇機進行第二次交會對接。組合體運行結束後，飛船於一天內返回地面。「天宮一號」將升軌至自主飛行軌道，轉入長期運行管理模式，等待下次交會對接。太空交會對接試驗是世界公認的航天技術難題，目前只有美國、俄羅斯可獨立完成。武平表示，與美、俄早期交會對接試驗相比，中國「天宮一號」目標飛行器，在技術、經濟等方面具有3大優勢：一是目標飛行器可支持多次交會對接，減少發射次數。二是目標飛行器按中國後續太空實驗室要求設計，可在完成交會對接任務的同時，驗證太空站部分關鍵技術。三是還可同時開展太空科學實驗和技術試驗。武平指出，與中國此前載人航天任務相比，此次交會對接任務更有 4 方面難點。首先是技術要求高。發射神舟飛船的運載火箭入軌精度指標比工程前期有大幅提高；載人飛行器在軌壽命要求大幅提高。第二是新技術採用多。突破了運載火箭高精度迭代制導技術，組合體控制和管理技術等。第三是驗證難度大。儘管中國曾進行大量地面仿真和驗證試驗，但由於受地面環境和試驗條件限制，部分新研設備在太空環境下的功能性能指標無法得到全面真實的驗證，尚需通過飛行試驗考核。
Launch to pave way for space station
China will launch an unmanned module next week, paving the way for a planned space station, a spokesman for the space program said on Tuesday.Tiangong-1, or "Heavenly Palace 1", will blast off from Jiuquan Satellite Launch Center in Gansu province between Sept 27 and 30, the spokesman said.The 8.5-ton module, and the Long March II-F rocket that will carry it skyward, were positioned onto the launch pad on Tuesday, signaling that the project has entered the final preparation stage."Scientists will conduct final tests in the next few days before injecting propellants for the launch," Cui Jijun, director of the Jiuquan Satellite Launch Center, said.The program spokesman said that Tiangong-1 will serve as "a target spacecraft" for rendezvous and docking experiments.It will also work as "a platform to test long-term unmanned and short-term manned operations", he said. Technical and medical experiments will provide crucial data ahead of the building of the space station (scheduled for 2020). Three rendezvous and docking experiments will be conducted. An unmanned Shenzhou-VIII craft will be launched later this year to dock with Tiangong-1. In 2012, Shenzhou IX and Shenzhou X will blast off to complete at least one manned docking. Jiao Weixin, a space scientist at Peking University, said that rendezvous and docking - vital maneuvers for manned programs - are hard to master. "Rendezvous and docking are difficult because it is like asking two racing cars to keep a distance of 1 meter between them," he said. The mission requires two craft, traveling at speeds of 28,000 km/h, to enter the same orbit and connect with precision, he said. The China Manned Space Engineering Office rescheduled the launch of Tiangong-1 after the failed launch of an experimental orbiter last month. The spokesman said that the carrier rocket to blast off with Tiangong-1 atop has been modified. Only the United States and Russia have mastered rendezvous and docking technology, said Pang Zhihao, deputy editor-in-chief of the magazine Space International. Spacecraft developed by Europe and Japan have utilized US and Russian technology to dock with the International Space Station, he added.
