Passage Four
　　Many people have looked to the stars and wondered what it would be like to take a trip into outer space. Ever since the space program began, traveling beyond Earth has been a privilege for a select few, namely, astronauts. The rest of us have had to imagine what it would be like, but that may soon change.
　　Those who favor expanding space exploration feel that it is time to go beyond the government-funded National Aeronautics and Space Administration (NASA) program and to create opportunities for individuals and businesses to explore outer space. Imagine privately financed research outposts in space, missions to Mars, and mining operations on the Moon. The space frontier could indeed be the next gold rush!
　　Imagine what it would be like to travel in space. Those who have been lucky enough to visit space have all called it an amazing experience. The view of Earth and the stars must be spectacular, and the experience of living in “zero gravity” would be fascinating. The first American woman to visit space, Sally Ride, said that it was the greatest fun of her life. Imagine the thrill of booking a flight for a weekend stay (or longer) at a space hotel. It turns out that a space hotel would be much easier to design and build than the International Space Station; early estimates of the cost to build the hotels indicate that they would be less expensive if the orbiting hotels were built to accommodate large numbers of space travelers.
　　The space hotel and the other projects businesses might think up would allow people to see what is happening in space with their own eyes. That may lead to more support of NASA and its space research and greater appreciation of the funding that the space program now receives.
　　Those who oppose expanding space exploration argue that the costs are overwhelming and unrealistic. They point to the billions of dollars that would have to be raised through consumers or corporate sponsorship. In addition, civilian space travel is potentially dangerous, and there are many unknown risks involved.
　　Who would determine the safety of commercial orbiting vehicles, and how would they be insured? Issues like this require time for discussion among groups from many different businesses. Companies that specialize in manufacturing, travel, marketing, insurance, law, and finance would all have to be involved.
　　Others believe there are simply too many unanswered questions to put civilians in space any time soon. There are also those who question investing in space exploration when there are widespread problems like poverty and disease that need to be addressed on Earth. For these people, commercial space travel will remain science fiction, at least for many years to come.The expression “the next gold rush” (Para. 2) probably means that _____.

A.predicts

B.involves

C.replaces

D.affects