First of all, space exploration and space exploitation are different things. Exploration is going places to learn new things, like the missions to Mars, Jupiter, and Saturn. This falls into the category of pure science but it does have applications to life here on Earth as well. Comparative analysis with other planets helps make sciences like geology, climatology, meteorology, and perhaps one day biology more robust because we'll have increased our knowledge base.

Many people have listed benefits from the space program, but virtually all of those are examples of space exploitation rather than exploration. Here are but a few examples where space technologies have become a part of our daily lives.

Civilian Uses

Communications: Some 75% of American households subscribe to cable TV. Virtually all of the non-local channels are delivered to the cable provider via communications satellites. Millions of other households get their programming directly from satellite services like DirectTV or Echo. That's only the beginning. A few years ago, a single communications satellite malfunctioned and stopped service. As a result, millions of people learned their ATMs went through that satellite. Millions of others learned that those credit card processing systems at gas pumps also used that satellite, as did millions of pagers. Communications satellites literally touch the lives of millions of people every day and most of them don't even know it. The case is even more profound in countries that lack an extensive fiber optic network. Countries like India and Indonesia have found satellites invaluable for quickly establishing a communications infrastructure.

Weather: When was the last time a hurricane struck without warning? Before weather satellites, that's when. These satellites help save thousands of lives every year. Maybe that bone-head political science (an oxymoron if there ever was one) professor thinks that's a bad idea. He seems to be rather hostile to the human race.

Earth Sciences: A series of Earth sciences satellites are being used ever day to track pollution, monitor the environment, track crop diseases, etc.

Military Uses

Navigation: The military GPS system is rapidly becoming the backbone for both military and civilian navigation. The FAA is redesigning the entire air traffic control and navigation system around GPS technology. You can get GPS receivers for cars to help you navigate more efficiently. Geologists are using highly accurate GPS receivers to monitor plate tectonics with the hope of one day being able to predict earthquakes. Of course, these satellites were designed and built for military purposes. They do those purposes very well. In WWII, hundreds of bombers were sent to attack a single target. Today, one or two F-15Es or B-2s can hit the same target with a higher probability of success and far fewer civilian casualties.

Communications: The military depends on a host of communications satellites for command and control around the world.

Intelligence Assets: The biggest fear that has driven the military and civilian leadership for the last 55 years has been the spectre of a "Pearl Harbor" in the nuclear age. Intelligence satellites have allowed us to keep track on what is going on in the world and to conduct war more efficiently.

Launch Detection: These satellites let us know whenever a missile is launched anywhere on Earth. It serves both strategic and tactical purposes. For example, we know almost immediately whenever a long range missile is launched so the chances of a surprise attack are very slim. At the same time, these satellites were used to detect Scud launches in the Gulf War in time to alert the defenses.

As for his professor's apparent hostility to humanity (I base that on his "lets destroy the earth and take it for all its worth and leave nothing for our descendants" statement), perhaps he needs to read Stephen Chapman's column about environmentalist rhetoric. It seems a Danish professor and Greenpeace environmentalist decided to examine the issues and found things aren't as bad as we're being led to believe. As a result, he wrote a book titled "The Skeptical Environmentalist" that lists his findings. Sounds like a good book.