inadequate precious for example fund program
auto-deployed explorer install cost robotic
unforseeable require picture crew launch
demonstrate reason flexibility space expensive
Criticism of human space flight comes from many quarters. Some critics point to the high 1 of manned missions. They contend that the National Aeronautics and Space Administration has a full slate of tasks to accomplish and that human space flight is draining 2 from more important missions. Other critics question the scientific value of sending people into space. Their argument is that human space flight is a(n) 3 "stunt" and that scientific goals can be more easily and satisfactorily accomplished by 4 spacecraft.
But the actual experience of astronauts and cosmonauts over the past 40 years has decisively shown the merits of people as 5 of space. Human capability is required in space to install and maintain complex scientific instruments and to conduct field exploration. These tasks take advantage of human 6 experience and judgment. They demand skills that are unlikely to be automated within the foreseeable future. A program of purely robotic exploration is 7 in addressing the important scientific issues that make the planets worthy of detailed study.
Many of the scientific instruments sent into space 8 careful emplacement (放置) and alignment (排列) to work properly. Astronauts have successfully deployed instruments in Earth orbit and on the suce of Earth"s moon. In the case of the 9 telescope, the repair of the originally flawed instrument and its continued maintenance has been ably accomplished by space shuttle 10 on servicing missions. From 1969 to 1972 the Apollo astronauts carefully set up and aligned a variety of experiments on the lunar suce, which provided scientists with a detailed 11 of the moon"s interior by measuring seismic (地震的) activity and heat flow. These experiments operated flawlessly for eight years until shut down in 1977 for fiscal rather than technical 12 .
Elaborate robotic techniques have been envisioned to allow the remote emplacement of instruments on planets or moons. 13 , suce rovers could conceivably install a network of seismic monitors. But these techniques have yet to be 14 in actual space operations. Very sensitive instruments cannot tolerate the rough handling of robotics deployment. Thus, the 15 versions of such networks would very likely have lower sensitivity and capability than their human-deployed counterparts do.