In December of 2006, while receiving Britain’s highest scientific award, the Royal Society’s Copley Medal, Stephen Hawking stated that if the human race were to survive, it would be necessary to travel beyond planet Earth: “The long-term survival of the human race is at risk as long as it is confined to a single planet.”

However, he acknowledges that colonizing other worlds and interstellar travel present a number of nearly insurmountable challenges. “If we used chemical fuel rockets like the Apollo mission to the moon, the journey to the nearest star would take 50,000 years. This is obviously far too long to be practical.â€?

Successful manned space exploration will require not only a lot of money and technological expertise, but an advanced understanding of human psychology. Quite frankly, manned space exploration presents so many problems, that it downright sucks.

1. Psychological Stress. Benny Elmann-Larsen, coordinator of physiology in human space flight at the European Space Agency, says psychological stress could be the biggest problem of all.

A trip to the moon would last only a few days, which is short enough to be bearable. But life on a lunar colony or a trip to Mars would present months of confinement, boredom and monotony.

In fact, the sense of isolation and cabin fever could become oppressive. A 110 day isolation experiment carried out on a mock space station in Moscow showed how badly things can become. One module housed four Russian men; the other, three international test subjects, from Austria, Canada and Japan.

During a New Year’s celebration, two of the Russian men engaged in a 10 minute fist fight that left blood on the walls before they were restrained by the other men. And the mission commander hauled the only female, a Canadian, out of sight of the experiment’s cameras and twice gave her a French kiss that she fought in vain to resist.

The Japanese participant was so traumatized by this episode that he quit the experiment altogether.

2. No emergency care. Ailments such as motion sickness and impaired coordination, to toothaches and appendicitis would be difficult to treat. There would be few supply flights, or quite possibly none at all. And the distances could become so great that it would require 45 minutes for people on Earth to receive a question from a crewmember, and another 45 minutes to receive a reply.

3. Radiation. High-speed particles in space can slice human DNA, increasing the risk of cancer, cataracts, neurological disorders, and other problems. Without proper shielding (limited by spacecraft weight and design and increasing costs), astronauts would be bombarded by so much cosmic radiation on a trip to Mars that 1 in 10 of them could die from cancer. We would also have to address the problem of shielding people while on other moons and planetary bodies that lack Earth-like atmospheres.

4. Muscular Atrophy. Traveling through space requires a strict exercise regime in order to overcome the loss of muscle tone due to zero gravity.

5. Bone Demineralization. Bones become more porous, and thus weaker, on long-duration space missions.

6. High cost. Because space is so hostile for humans, all our needs must be met by creating a hospitable environment in space. Missions in space must be meticulously planned in order to avoid stressing our fragile bodies. We need food, water and air, all of which requires complicated and heavy equipment. All this machinery needs to be monitored, reducing an astronaut’s available time to carry out experiments. And it substantially reduces the payloads spacecraft can carry.

Currently, it’s estimated that just the shuttle program average cost per flight has been about $1.3 billion over lifetime and about $750 million per launch over its most recent five years of operations. This total includes development costs and numerous safety modifications. That means each shuttle launch could pay for 2 to 3 unmanned missions.

7. It can be used to further nationalistic agendas. The race to the moon was a direct consequence of the cold war between the United States and the Soviet Union. And now we can see the same thing happening with China’s manned space exploration programs. While competition can certainly be healthy, cooperation would more likely reduce conflicts.

8. Robots and telescopes may be more effective at increasing scientific knowledge. Most scientists agree that both the space shuttle and the International Space Station are an expensive and unproductive means to conduct space science.

However, the Mars Pathfinder and Mars Exploration Rovers have succeeded beyond the expectations of their designers and continue to deliver important data to earthbound scientists. Also, when the successful Deep Impact mission smashed into comet Temple, it released a cloud of debris that helps the understanding of comet formation and composition.

Such feats would be prohibitively more expensive and difficult if humans were involved.

9. Shuttle explosions put further flights on hold indefinitely. These tragic events have the unfortunate side effect of slowing the progress of space exploration.