Manned space exploration is prohibitively expensive while providing limited spin-off benefits:  Space exploration costs enormous amounts of money. The United States spends tens of billions of dollars every year on its space program, and the Chinese and European space agencies are seeking to catch up technologically. Overall, the amount of money wasted is astronomical. Even if manned space flight were a desirable goal, the cost is far too great. Unmanned space flight offers the same benefits at far less expense, since unmanned vessels weigh less than those needed to carry humans, and do not require the expensive and sophisticated life-support technology necessary to sustain human life in the harsh wilderness of space. [1] Furthermore, the benefits accrued from spin-off technology resulting from space exploration are generally overstated. NASA, for example, had claimed that protein crystals could be grown in zero gravity that could fight cancer, as well as numerous other claims of benefits. Most of these benefits have never materialized. With all the billions of dollars wasted on manned space flight, most of the spin-off technologies could likely have been created independently, given the resources, and probably at lower overall expense.  [1] Kaku, Michio. “The Cost of Space Exploration”. Forbes. 2009.