Manned space flight is a technological dead end  Manned space flight appears to have little practical use. While its supporters talk about traveling to other planets, the technology simply does not exist, nor may ever exist, to send humans to worlds that could be even potentially habitable. It may be possible to send humans to Mars, or the moons of Jupiter and Saturn, but doing so would have little value other than for the sake of planting boots on alien soil. [1] Any research worth conducting on planets within the solar system can be done just as well by robots, at considerably less expense. The laws of physics seem to show that it is impossible for ships to travel at or past the speed of light, meaning any journey to planets beyond the solar system would take centuries at least. It is unlikely, for this reason, that manned space travel will ever be a practically useful endeavor. Research should be put into technology that can actually lead humanity somewhere. There is nowhere for humans to go in space that robots cannot, and nowhere worth the cost of their going.  [1] Leath, Audrey. “Should Mars Be Human Space Flight Objective?”. American Institute of Physics 2003.