Space: Onward to Mars

From the Kennedy Space Center and the Soviet Union's Baikonur Cosmodrome, powerful shuttles and unmanned rockets lift off week after week, bearing construction modules and fuel supplies to a giant space station in earth orbit. There, skilled workers have been assembling the ship that will take the first humans to Mars. After more than a year of construction, the million- pound, ungainly looking spacecraft is ready. With a crew of eight, it separates from the space station and heads for Mars, following the Hohmann ellipse, a space trajectory that may one day be as familiar as a great-circle route over the...