Our Non-Expeditions to the Moon and Mars
Look closely: President Bush's space initiative
is more about robots than astronauts
Richard A. Muller
February 19, 2004
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.'
Will anyone take that to be an enthusiastic endorsement of the space station? How will our 15 international collaborators interpret his word 'finish'? The only value of the space station that President Bush cited was study of the biology of human endurance in a weightless environment. He mentioned no other scientific purpose, and rightly so. Most scientists launching space experiments prefer a satellite isolated from human pollution and noise, and unencumbered by the added expense of making it safe for humans to work around.
The replacement for the shuttle, the 'Crew Exploration Vehicle,' will be operational 'no later than 2014,' the president said. There may be four years, 2010 to 2014, when the U.S. can't fly to the space station. Is that a golden opportunity for Russia to take over the business of shuttling people and cargo to the station? Or is it a signal that it is time for our 15 collaborators to cut their losses, too? I'm guessing that by the time the Crew Exploration Vehicle is ready to go there, the space station will have long since been abandoned.
Before the Columbia tragedy, the Hubble Space Telescope had been scheduled for a repair and upgrade visit in 2005. Now, however, NASA is asking whether such a mission is worth the risk to astronauts. Instead, NASA is considering spending $300 million to develop a robotic tug that will attach itself to the telescope and crash it into the ocean, to make sure the instrument's return to earth does no harm to humans. The thought of destroying Hubble has triggered much sound and fury among scientists. There is great irony here, for the dispute illustrates NASA's success in addicting scientists to a vehicle that they never wanted. It is not the Mars mission that threatens Hubble--it is the cancellation of the shuttle, something that should be done regardless of Mars.
Here are some key points. First, $300 million to deorbit Hubble safely would represent the most money ever spent per life saved in the history of mankind, by far. A mere million dollars spent on improving ambulance service in the United States would save many more lives; even better would be sending medicine to impoverished regions of the world. Second, Hubble was designed to be human-serviceable not to save money, but to provide a scientific excuse for the shuttle. It is arguably cheaper to start building next-generation astronaut-free systems than to continue servicing the present telescope. Third, a trip to Hubble is more dangerous than a trip to the space station, because it offers no chance to repair tiles damaged on launch.
Either mission risks the lives of astronauts, and the decision will not be easy. But if the decision is between a dangerous trip to the space station, with no scientific return, and a more dangerous trip to Hubble, with enormous return, I think the United States will decide for Hubble. My reading of President Bush's speech is that the only achievement worth risking human life for is knowledge and exploration--and for that, you can't beat Hubble.
President Bush's speech has been widely characterized as a plan to send astronauts to the moon and Mars. But the goal for reaching the moon is 2020, and for Mars it is 2030. This isn't a plan, or a program--it's more like a long-term dream.
Let's look at what will actually happen by the end of this decade under President Bush's plan. The shuttle will be cancelled, and the space station will be abandoned. Only one of the goals announced by Bush could take place within his presidency. Back to his speech: 'Beginning no later than 2008, we will send a series of robotic missions to the lunar surface to research and prepare for future human exploration. Robotic missions will serve as trailblazers, the advanced guard to the unknown. Probes, landers, and other vehicles of this kind continue to prove their worth, sending spectacular images and vast amounts of data back to Earth.'
President Bush is right. The space shuttle and the space station deserve termination. The true heart of his proposal is the elimination of these programs, and the substitution of robotic exploration. We will look before we leap--that is, fly telescopes built for visible, infrared, ultraviolet, microwave, x-ray, and gamma ray wavelengths--to see what we can see from Earth orbit. Then we will send robots to explore whatever robots can explore. Hold back on the astronauts until we have goals that need them. Let science be the guide, rather than a presumed human need to step off the surface of the Earth.
Some people will say I am too optimistic, that I am reading too much in between the lines. I think I am just ignoring the headlines to read the actual lines themselves. President Bush gave us a great plan. Let's recognize that and go with it. But let's be careful to make sure that politicians and bureaucrats do not hijack President Bush's wonderful vision of robotic space exploration and degrade it into a listless program that merely launches astronauts to places where telescopes and probes could do a safer, quicker, better, and cheaper job.
Richard A. Muller, a 1982 MacArthur Fellow, is a physics professor at the University of California, Berkeley, where he teaches a course called 'Physics for Future Presidents.' Since 1972, he has been a Jason consultant on U.S. national security.