ambermichelle writes with an excerpt from an article in Txchnologist: "Going to Mars? Expect to stay a while. Because of the relative motions of Earth and Mars, the pioneering astronauts who touch down on the Martian surface will have to remain there for a year and a half. For this reason, NASA has already started experimenting with a habitat fit for the long-term exploration of Mars. Last year, students at the University of Wisconsin won the XHab competition to design and build an inflatable loft addition to a habitat shell that NASA had already constructed. The final structure now serves as a working model that is being tested in the Arizona desert. Like any home, it's a sacred bulwark against the elements; but not just the cold, heat, and pests of Arizona. A Mars habitat will have to protect astronauts from cosmic rays, solar flares, and unknown soil compositions all while keeping inhabitants happy and comfortable."
egrep patterns are full regular expressions; it uses a fast deterministic
algorithm that sometimes needs exponential space.
-- unix manuals