首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The 10th launch of the space shuttle Challenger was scheduled as the 25th space shuttle mission. Francis R. (Dick) Scobee was th
The 10th launch of the space shuttle Challenger was scheduled as the 25th space shuttle mission. Francis R. (Dick) Scobee was th
admin
2010-07-19
57
问题
The 10th launch of the space shuttle Challenger was scheduled as the 25th space shuttle mission. Francis R. (Dick) Scobee was the mission commander. The crew included Christa McAuliffe, a high-school teacher from New Hampshire. The five other crew members were Gregory B. Jarvis, Ronald E. McNair, Ellison S. Onizuka, Judith A. Resnik, and Michael J. Smith.
After several launch delays, NASA officials overruled the concerns of engineers and ordered a liftoff on a cold morning, Jan. 28, 1986. The mission ended in tragedy. Challenger disintegrated into a ball of fire. The accident occurred 73 seconds into flight, at an altitude of 14020 meters and at about twice the speed of sound.
Strictly speaking, Challenger did not explode. Instead, various structural failures caused the spacecraft to break apart. Although Challenger disintegrated almost without warning, the crew may have briefly been aware that something was wrong. The crew cabin tore loose from the rest of the shuttle and soared through the air. It took almost three minutes for the cabin to fall to the Atlantic Ocean, where it smashed on impact, killing the seven crew members.
All shuttle missions were halted while a special commission appointed by President Reagan determined the cause of the accident and what could be done to prevent such disasters from happening again. In June I986, the commission reported that the accident was caused by a failure of O rings in the shuttle’s right solid rocket booster. These rubber rings sealed the joint between the two lower segments of the booster. Design flaws in the joint and unusually cold weather during launch caused the O rings to allow hot gases to leak out of the booster through the joint. Flames from within the booster streamed past the failed seal and quickly expanded the small hole. The flaming gases then burned a hole in the shuttle’s external fuel tank. The flames also cut away one of the supporting beams that held the booster to the side of the external tank. The booster tore loose and ruptured the tank. The propellants (火箭燃料) from the tank formed a giant fireball as structural failures tore the vehicle apart.
The commission said NASA’s decision to launch the shuttle was flawed. Top-level decision makers had not been informed of problems with the joints and O rings or of the possible damaging effects of cold weather.
Shuttle designers made several technical modifications, including an improved O-ring design and the addition of a crew bail-out system. Although such a system would not work in all cases, it could save the lives of shuttle crew members in some situations. Procedural changes included stricter safety reviews and more restrictive launching conditions. The space shuttle resumed flying on Sept.29, 1988, with the launch of the redesigned shuttle Discovery. (465 words)
The word "overrule" in the first sentence of paragraph 2 means ______.
选项
A、share
B、ignore
C、consider
D、know
答案
B
解析
overrule指上级权力机关对下级机关的建议、异议等的否决或驳回。
转载请注明原文地址:https://kaotiyun.com/show/VklO777K
0
专业英语八级
相关试题推荐
ClassicIntentionMovementInsocialsituations,theclassicIntentionMovementis"thechair-grasp".Hostandguesthavebe
ChileisdisadvantagedinthepromotionofitstourismbyAccordingtothepassage,inWHICHareaimprovementisalreadyunder
ChileisdisadvantagedinthepromotionofitstourismbyManyofChile’stouristsusedtocomefromEXCEPT
IfyouwanttoseeaperformancebytheBeijingPekingOperaTheatre,whichphonenumberwouldyouring?Supposingyouhavesom
MarkTwain,oneofthegreatest19thcenturyAmericanwriters,iswellknownforhis
Specialwordsusedintechnicaldiscussion______.Thewriterofthearticlewas,nodoubt______.
InBritain,thetopspectatorsportisfootball.Thissportwasseriously【1】_____asanorganizedgamein1848Later,theFoo
今天的老年人是昨天的劳动者。他们对物质文化的发展作出了许多贡献,理所当然应享受物质文化发展的成果。若全社会都把尊敬老人看作当代的美德,人们就会有一种安全感。这使得各个年龄层的人都感到他们将来的日子肯定也是愉快的,就会全力以赴地投入工作。去年,宣武医
DidMarcoPoloTelltheTruth?ThereisacontroversyaboutMarcoPolo’striptoChina.DidMarcoPolotellthetruth?Ifyo
DidMarcoPoloTelltheTruth?ThereisacontroversyaboutMarcoPolo’striptoChina.DidMarcoPolotellthetruth?Ifyo
随机试题
下列对于县级司法行政机关的描述,错误的是()
下列属于无形资产的有()
婴儿期持续性青紫,见于
依法从轻或减轻行政处罚的情形有
【2013—3】题11~15:某企业新建35/10kV变电所,10kV侧计算有功功率17450kW,计算无功功率11200kvar,选用两台16000kVA的变压器,每单台变压器阻抗电压8%,短路损耗为70kW。两台变压器同时工作,分列运行,负荷平均分配,
当平原、滨海地区的水利水电工程其永久性水工建筑物的挡水高度高于()m,且上下游水头差大于()m时,其洪水标准宜按山区、丘陵地区标准确定。
()是指单位类客户在商业银行开立结算账户,办理不规定存期、可随时转账、存取的存款类型。
Afterthehorrorbecamepublicinhishometown,Sylacauga,Alabama,citycouncilpresidentGeorgeCarltontoldareporter,"Thi
EffectiveAssignmentsUsingLibraryandInternetResourcesI.Setting【T1】andmakingthemcleartostudents【T1】______—developing
It’sagoodideatoapplysunscreenbeforeheadingtothebeachifyoudon’twanttoburn.Butformarineanimalslikewhales,t
最新回复
(
0
)