美国国家科学院空间科学委员会上星期对国会说航宇局应该在政策上作一次重大变革,应该重新退回到以不载人的运载火箭作为主要运载工具运送科学卫星入轨。为了为其提议筹集资金,该委员会建议推迟生产一架航天飞机替补失事的挑战者号航天飞机,延缓美国/国际空间站 The US National Academy of Sciences Space Science Committee told Congress last week that NASA should make a major policy change and should return to re-entering the scientific orbit with an unmanned launch vehicle as its main carrier. In order to raise funds for its proposal, the Commission recommended a postponement of the production of space shuttle Challenger, a replacement space shuttle, to delay the U.S. / International Space Station