National Aeronautics and Space Administration - the successor of the earlier National Advisory Committee for Aeronautics. Begun in 1958, largely in order to gain a moral victory in the Cold War by beating the USSR to the moon, their main purpose is to gain knowledge about outer space and neighboring celestial objects in order to increase humanity's knowledge of the cosmos. Initially well-funded and manned by some of the greatest scientists of the 20th century, the Administration's space programs helped to develop some of the most influential and often-used technology of the modern day (satellite technology, computers, electronic miniaturization, temperature resistant materials, etc.). Unfortunately, due to the multitude of early successes and prevailing opinion in Washington, NASA is often expected to do more with less money, as Congress often slashes budgets and expects better service. Not wanting to lose the tradition of innovation, NASA has recently tried to appease the government and an ever-increasing public ignorance of the benefits of scientific exploration, and as a result has tried to do more than they should, resulting in the 1986 Challenger explosion, and the heat shield failure of the Columbia in 2003, along with less deadly failures of Mars probes.
NASA fails because we allow it to; we expect that becuase "those NASA guys are geniuses" that they can do something with next to nothing. Space travel has always been, and will always be dangerous.