美国第二架航天飞机挑战者号的首次飞行原计划在今年一月中旬起飞,现已推迟到三月二十日左右。原因是:1.它的三台主发动机中一台有渗漏,2.匆匆换上的另一台备用发动机也有渗漏。目前,从哥伦比亚号上借来的备用发动机已准备就绪。故障造成的发射停顿使航宇局损失了数百万美元,更重要的是可能会扰乱今年的其它4次航天飞机飞行。据航宇局总部发动机计划主任说,故障 The first flight of the U.S. space shuttle Challenger was originally scheduled to take off in mid-January of this year and is now postponing until March 20. The reasons are: 1. Leakage of one of its three main engines, 2. Leakage of another backup engine hurriedly replaced. Currently, the backup engine borrowed from Columbia is ready. A standstill caused by the failure caused NASD to lose millions of dollars and, more importantly, could disrupt this year’s four other space shuttle flights. According to NASA headquarters director of engine program, said failure