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The shuttle has been grounded for
two-and-a-half years | |
Nasa has set 13 July as the launch date for
Discovery, the first shuttle
to go into space since the Columbia disaster in February 2003.
The announcement follows a two-day review of the Discovery's readiness
for lift-off.
An original launch date in May was put back because of ongoing redesign
work on the shuttle's fuel
tank.
Columbia disintegrated after re-entering the Earth's atmosphere,
killing all seven astronauts on board.
Earlier this week, a panel monitoring Nasa said the agency had failed
to meet three of 15 recommendations made by the Columbia Accident
Investigation Board for the safe resumption of shuttle flights.
But Nasa Administrator Michael Griffin said Discovery was fit for
launch.
"Based on a very thorough and very successful flight readiness review,
we're currently 'go' for launch of Discovery on 13 July," he announced.
An earlier investigation found Columbia broke up as a result of damage
sustained when a chunk of fuel-tank insulating
foam smashed into its left wing during lift-off two weeks
earlier.
The Caib probe concluded astronauts would still be unable to fix such
damage once in orbit.
While Nasa's focus was on how to prevent the insulating foam breaking
off, concerns also emerged earlier this year about the build-up of ice on
the outside of the fuel tank.
The agency's management however decided the risk of ice striking the
shuttle's heat shield was low enough to resume flights.
Discovery will carry a seven-strong crew
on a mission to take supplies and parts to the International Space
Station.
(Agencies) |
美國宇航局(NASA)日前宣布將于7月13日發射“發現”號航天飛機。這將是美國航天飛機自2003年2月“哥倫比亞”號失事以來首次恢復發射。
之前,美國宇航局已對“發現”號的發射準備工作進行了為期兩天的檢查。
“發現”號原定于今年五月發射升空,但是由于當時正對飛船的油箱重新進行設計,而不得不推遲了發射日期。
“哥倫比亞”號航天飛機在返回地面途中,經過地球大氣層時解體,導致機上七名宇航員全部遇難。
本周早些時候,一個美國宇航局監督小組聲稱,宇航局未能滿足哥倫比亞事故調查委員會為恢復航天飛機安全飛行而提出的15條意見中的3條。
但是,美國宇航局局長邁克爾·格里芬卻宣布,“發現”號已經做好了發射升空的準備。
他說:“我們對發射準備工作進行了非常全面且成功的評估,現決定在7月13日發射‘發現’號航天飛機。”
早先進行的調查發現,在“哥倫比亞”號航天飛機發射升空時,從外部燃料箱脫落的一塊泡沫絕緣材料擊中了航天飛機左翼,使其受損,從而導致了兩周后“哥倫比亞”號在空中解體爆炸的悲劇。
哥倫比亞事故調查委員會經過周密調查后得出結論:萬一航天飛機在軌道運行中發生類似的損壞,宇航員仍舊無法展開修復工作。
正當美國宇航局將工作重點放在如何防止泡沫絕緣材料脫落時,今年年初人們又開始擔心燃料箱外側集結的冰是否也會對航天飛機的飛行安全構成威脅。
然而,美國宇航局的管理層斷然認為,這些冰塊擊中航天飛機防熱護罩的風險極低,不會影響航天飛機的飛行。
“發現”號將把一個“身強力壯的”七人小組送入太空,給國際空間站帶去補給和一些部件。
(中國日報網站譯) |