Space travel has been possible for some time and some people think the space tourism could be developed in the future.To what extent do you think it's a positive or negative development？

范文：
Mankind has always been a race of explores,and many possible technologies exist to enable us to experience space travel. However,there is a great deal of controversy regarding space tourism. In my opinion,this development is more likely to produce positive outcomes for individuals and the world.
Obviously,the impetus of looking beyond the horizon has driven the development of this trend. Simply by exploring the outer space,individuals’ curiosity would be satisfied. This would be more exciting than seeing unfeeling robots on TV. Furthermore,this would probably serve to unite humanity,which means that a sense of citizenship for Earth may be achieved. In this way,space travel actually promotes peace and understanding among nations.

There is also an economic argument for encouraging space tourism. With the promise of new technology,space travel services are likely to be capable of growing rapidly into a major new industry in the future. This would create a wide range of new business opportunities,such as pilots,stewardesses and control tower workers. Consequently,this would be very beneficial for world economic growth,for unemployment is more-or-less high throughout the world.

There are,however,some dangers of developing this new industry to a large scale. One main concern would be the high consumption of fuel source and air pollution. Another danger would be the hazards of traveling in the outer space,as this is ever more dangerous than other kinds of extreme sports. However,these problems could be tackled strategically with alternative energy,and the safety and security would be ensured by developing a reliable orbital infrastructure.
In conclusion,although space tourism could be dangerous to a certain extent，I do believe this development would be extremely positive,and therefore it would be essential to promote and fund it.

词汇拓展：
Impetus： 动力，势头
Outer space： 太空
Pilot： 飞行员
Stewardess： 乘务员
Hazard： 危险，危害
Orbital： 轨道的