单项选择题

Text (26) Space Agency is planning to (27) a spacecraft to the planet Mars. The spacecraft will be called Mars Observer. The project was to have (28) place in 1990. But it has been postponed. The Space Agency now (29) to send the spacecraft to Mars in 1992. The Mars Observer is to (30) from an America’s space shuttle. It will then (31) around tile North and South Poles of Mars. The spacecraft will have cameras to (32) pictures of the atmosphere and surface of Mars. Its major task is to look (33) signs of life. The last voyage (34) Mars was in 1976. That was (35) the two American Viking spacecrafts land- ed on the planet. The next voyage was planned (36) 1988 by the Soviet Union. America’s Mars Observer Project will (37) about $ 25.000.000. The high cost is one reason the Space Agency postponed the project. A (38) of scientists have criticized that decision. Carl Sagan of Cornell university (39) it "a great mistake". And the head of the Planetary Society said the project should not be postponed now (40) it appears to (41) support in Congress. Congress must (42) money for it. Some scientists have proposed a solution that would save (43) time and money. They say the Mars Ob- server be launched in 1990 (44) planned, but on a traditional rocket (45) of the space shuttle.