Shuttle begins slow creep to launch pad	“发现”号航天飞机登上发射台
Shuttle Discovery sits on top of launch pad 39B after making its way from the Vehicle Assembly Building at the Kennedy Space Center in Cape Canaveral, Florida, April 7, 2005. (REUTERS/Charles W. Luzier) Space shuttle Discovery began its slow creep to the launch pad Wednesday after a brief delay caused by the discovery of a crack in the external fuel tank's foam insulation . NASA later said the crack was no reason for concern. The flaw was discovered as the spacecraft was being readied for the first shuttle launch since Columbia fell to pieces two years ago - a disaster blamed on a chunk of foam that fell off the tank during liftoff and gashed one of the wings. NASA spokeswoman Jessica Rye described the flaw as a hairline crack and said after sending images of it to the tank's manufacturer in Louisiana, the space agency concluded it did not need to make any repairs. NASA later said the 1 1/2-inch crack was high up on the shuttle in a spot where if foam flew off it would not likely hit the vehicle. NASA then began moving Discovery from its assembly building to the launch pad, after a delay of at least two hours. Because of Columbia's disintegration over Texas in 2003 - and the deaths of all seven astronauts aboard - the tank has been extensively redesigned for Discovery's flight. NASA plans a mid-May liftoff with a launch window from mid-May to June - a period dictated by the position of the international space station, the shuttle's destination. Discovery was being moved on a 5.5 million-pound transporter, a huge platform on caterpillar tracks, along a specially built road that is almost as wide as an eight-lane highway. The 4.2-mile journey to the launch pad was expected to take hours, since the transporter moved at only 1 mph. The move went smoothly until gauges gave off false indications about whether the vehicle was level as it climbed a ramp leading to the launch pad. The transporter was backed up to level ground so workers could determine if there was a problem with the gauges. "It's a great sight to see Discovery rolling out to the launch pad," shuttle commander Eileen Collins, who will lead the crew on the next mission, said from Mission Control in Houston. "We know we are getting close." （Agencies)	本周三（4月6日），美国“发现”号航天飞机被缓慢移送到发射台上，之前因其外部燃料槽的泡沫绝缘材料被发现有一处小裂缝，迁移行动延迟了一小会。美国国家航空与宇航局稍后表示这处裂痕无关紧要。 这处裂痕是在航天飞机正准备进行首次发射时发现的。两年前，（承载相同任务的）“哥伦比亚”号航天飞机刚一起飞就发生爆炸，裂成碎片。那场灾难要归咎于起飞后一大块泡沫材料从燃料槽上脱落，撞伤了一侧的机翼。 美国国家航空与宇航局发言人杰西卡·雷用“头发丝一样的细纹”来形容这一裂痕，并在将裂纹照片传给路易斯安那的燃料槽生产商后表示，宇航总局认定这点小毛病不需要任何检修。 美国国家航空与宇航局后来声明，这道1.5英寸长的裂纹位于航天飞机的顶部，即使泡沫材料从那个位置掉落下来，也不可能砸到飞行器。 然后，美国国家航空与宇航局开始将“发现”号从装配大楼移送到发射台，这比原定时间至少推迟了两小时。 2003年，“哥伦比亚”号在德克萨斯州上空爆炸解体，机上的七名宇航员全部丧生。正因为这一事件，“发现”号的燃料槽经过了彻底的重新设计。 美国国家航空与宇航局计划在五月中旬发射“发现”号，并将发射时限设定在五月中旬到六月之间，这一时间是根据国际空间站（航天飞机的目的地）的位置设定的。 “发现”号沿着专用坡道被运送到运输机（一个放在运输履带上的巨型平台）上，那条坡道差不多有八条高速路行车道那么宽。这趟4.2英里的旅程预计要花数小时，因为运输机重达550万磅，时速仅为每小时一英里。 搬移工作进展很顺利，除了当运输机攀爬上通往发射台的坡道时，测量仪器对车身的水平状态发出了错误的指示。运输车不得不退回到平地上，以便工作人员们检查测量仪器是否出现故障。 “看到‘发现’号终于爬上了发射台，这真是一幅壮观的景象。”航天飞机指挥官艾琳·柯林斯在休斯顿的任务控制处说，“我们知道自己离目标不远了。”柯林斯将率领全体工作人员完成下一次飞行任务。 （中国日报网站译）