Humans are natural travelers. We evolved into modern humans almost 200,000 years ago. In the last 50,000 years we have traveled across the earth and now live almost everywhere except for Antarctica. If environmental problems on earth continue to increase, one day we may need to find a new home in space.
Long distance space travel has become more of a possibility now that we can grow vegetables in space. Russian scientists on the International Space Station have succeeded in growing peas, leafy greens, and wheat in greenhouses.
While food is only one of many technological problems of space travel, there is a bigger problem that could stop space travel completely. Humans have not only polluted the ground, air and water of the earth, but now we have quickly spread our trash into space!
We increasingly use space satellites for television, communication, weather reports and navigation. In the last 50 years, there have been 5,000 space launches of satellites. Almost 4,000 of these satellites are now broken. These satellites sometimes break apart and hit each other, causing even more pieces of space junk. There are now 22,000 pieces of junk circling the earth. And these are just the large pieces. There are hundreds of thousands of smaller pieces of trash. This space junk is creating a growing problem for our plans of space travel.
In 2009, a Russian satellite and a US satellite traveling 42,000 km per hour hit each other. This caused an explosion that created 2,000 smaller pieces of trash. According to one NASA scientist, a piece of space trash half the size of a baseball can create an explosion that equals 7 kg of TNT. Astronauts on the International Space Station have twice prepared to escape the space station to avoid space junk. Both times the danger was avoided, but these problems will continue to increase. In 1978, a NASA scientist named Kessler predicted this problem. He said that the increase of space junk will make space travel and the use of satellites impossible in the future.
There are many ideas on how to clean up space junk. The Japanese are planning to launch a 700-meter magnetic net into space to catch space junk and bring it back to Earth. The Swiss are planning a robotic arm that will be a space janitor, grabbing pieces of trash. These plans will cost a lot of money.
Who should pay to clean up space junk? Some people say that the US, Russia, and China have put the most junk into space and should pay for more of the cleanup costs. Other people think that the only practical plan would be to tax future satellite launches, and use this tax money to pay for cleanup. This is an immediate problem. At least five to ten large pieces of space junk must be removed every year if we want to continue using and exploring space. What do you think about this problem? Will we one day travel beyond this planet for a new home in space?