Russia has postponed test launches of the troubled Bulava ballistic missile until November this year, the Russian defense minister said on Friday.

The latest launch of the missile, which Russia hopes will be a key element of its nuclear forces, from the Dmitry Donskoy nuclear submarine in the White Sea ended in failure in early December 2009. Only five of 12 Bulava launches have been officially reported as being successful.

The Russian Navy earlier planned at least four new test launches of the missile at the end of June, but defense industry experts suggested they would need to build three missiles under identical conditions to establish the causes of the failures.

"We should be ready to resume the [Bulava] tests by November, I think," Anatoly Serdyukov said during talks in Italy, which involved the defense and foreign ministers of both countries.

Serdyukov said that the problems with the missile apparentlyoriginate from the faultyassembly process.

"It all comes from the poor quality of assembly. But each failed launch has experienced different problems," the minister said, adding that only the testing of three identical missiles would allow the experts to pinpoint the cause of failures.

The Bulava (SS-NX-30) is a three-stage liquid and solid-propellant submarine-launched ballistic missile (SLBM). It carries up to 10 MIRV warheads and has a range of over 8,000 kilometers (5,000 miles).

The missile has been specifically designed for Russia's new Borey class nuclear submarines.

The future development of Bulava has been questioned by some lawmakers and defense industry officials who suggest that the Russian Navy should keep using the more reliable Sineva SLBM.

The Russian military has insisted that there is no alternative to the Bulava and pledged to continue testing the missile until it is ready to be deployed with the Navy.

MOSCOW, May 21 (RIA Novosti)

• minister [´ministə] n.部长；大臣 v.伺候 (初中英语单词)
• failure [´feiljə] n.失败；衰竭；破产 (初中英语单词)
• assembly [ə´sembli] n.集会；装配；与会者 (初中英语单词)
• liquid [´likwid] n.液体 a.流动的 (初中英语单词)
• launch [lɔ:ntʃ] vt.发动 n.发射；汽艇 (高中英语单词)
• submarine [´sʌbməri:n] a.海中的 n.潜水艇 (高中英语单词)
• identical [ai´dentikəl] a.完全相同的 (高中英语单词)
• apparently [ə´pærəntli] ad.显然，表面上地 (高中英语单词)
• originate [ə´ridʒineit] vt.发源；创造；引起 (高中英语单词)
• reliable [ri´laiəbl] a.可靠的；可信赖的 (高中英语单词)
• officially [ə´fiʃəli] ad.以职员身份；正式 (英语四级单词)
• experienced [ik´spiəriənst] a.有经验的；熟练的 (英语四级单词)
• alternative [ɔ:l´tə:nətiv] a.二中选一的 n.选择 (英语四级单词)
• faulty [´fɔ:lti] a.有毛病的；有故障的 (英语六级单词)