Many people think that in his January 14 speech on the space program, President George Bush announced a new initiative to return humans to the moon and soon afterwards send them to Mars. He didn’t. What he announced was a cancellation of the space shuttle and a reduction of the United States’ long-term commitment to the International Space Station. For the immediate future, he proposed an expanded program of unmanned exploration of space, with an emphasis on the planets and the solar system. I know-that’s not what most people read in the headlines of their papers. So let’s look at President Bush’s speech closely, with particular attention to the dates when missions will fly.The president used much of his speech to describe the great accomplishments of the space program. These included practical applications-unmanned satellites used to predict weather, to communicate, and to determine location (the Global Positioning System). But his real emphasis was on NASA’s scientific achievements, including our growing exploration of the universe. He mentioned the Apollo missions to the moon only in passing. He talked of images taken by telescopes, and knowledge sent back by “robotic explorers” including Spirit, the Martian rover. His emphasis on unmanned projects was surprising and significant. And he was right; the unmanned program is NASA’s most glorious achievement over the last three decades. Moreover, it is this aspect of space exploration that most excites the public. The Astronomy Picture of the Day fascinates schoolchildren and adults alike, many of whom download the images for screen savers. In contrast, stories of astronauts floating for months in the space station are considered so boring they don’t even make the back pages of newspapers, let alone the evening news.
Just as important in President Bush’s speech were his omissions. He made no mention of industry in space-of the possibility of rounder ball bearings or purer semiconductors. He made no reference to space travel so cheap that it becomes commonplace. Those ancient and hopeless goals, used in the original justification of the shuttle program, were abandoned, and for that I am thankful. They were never realistic, never made economic sense, and they interfered with legitimate science and exploration programs.
The greatest achievements in President Bush’s list did not relate in any compelling way to humans in space. Yes, the Hubble Space Telescope was launched and serviced by the shuttle, but most scientists believe that the telescope program would have accomplished even more per dollar spent if it had been designed and executed separately from the manned space program. Repairing and extending the life of this system using the shuttle is arguably more expensive than sending a new satellite aloft, particularly since the Hubble telescope had to be made safe for astronauts to be near. The military has launched spy telescopes for decades without need for human servicing. How big were they? Basic optics tells us that a telescope’s resolution depends on the diameter of its mirror. Do the simple math and you’ll find that the ability read a license plate from an altitude of 500 kilometers requires a mirror 3 meters across; the Hubble’s mirror is 2.4 meters.
President Bush announced that the shuttle will continue until 2010-but that’s only six more years of operation. He is ending the shuttle program. In its remaining life, the shuttle’s main goal will be to “complete” the International Space Station, to “finish what we have started.”