The next two decades will see another human being setting foot on the moon--------- On July 20, we will celebrate the 40th anniversary of the Apollo 11 moon landing. It was one of those moments when the world watched with awe as men took their first steps onto another world. Armstrong and Aldrin were followed by 10 other Americans and then the programme came to an abrupt end. Since 1972, no human being has ventured beyond low-earth orbit. If all goes as planned, and if NASA gets full funding over the next decade, an astronaut might be back on the moon in 2020. A half a century between human visits to our nearest celestial neighbour needs to be explained. The original mission was the result of a number of factors that came together at the right place at the right time. When president John F. Kennedy announced that America was going to "land a man on the moon and return him safely to the Earth", he was making a promise he was confident the US could keep given its technological superiority. Keeping the Apollo programme on track after that was largely a matter of politics and budgets. It was in those years that NASA came to absorb almost three per cent of the US federal budget. (Today it receives a little more than one half of one per cent.) The moon landing happened during the first year of the presidency of the man Kennedy had beaten in 1960, Richard Nixon, who was relatively indifferent towards NASA. The US civil space budget was cut drastically in the late 60s and 70s. Under Clinton, NASA was not even allowed to mention the words moon or Mars in the context of their exploration plans, so they had to create a euphemism: "accessible planetary surfaces". After the February 2003 Columbia disaster, George W. Bush allowed NASA to come up with a Vision for Space Exploration that was to be "sustainable and affordable". Twice now both houses of Congress have voted in favour of this project. However, it now faces considerable scrutiny from the Obama administration. The Soviet Union, of course, never was able to put a cosmonaut on the moon. Their giant N-l moon rocket failed in all four launch attempts. More recently, the Russians have proposed to launch a tourist flight, at a rate of $100 million, that would circle the moon, but not land. China has announced that they are interested in landing a taikonaut on the moon sometime between 2025 and 2030. India has also said that it is planning a manned mission to the moon. It seems certain that within the next two decades another human being is going to set foot on the moon. Whether it will be just a "flags and footprints" mission, as Apollo is often described, or whether it will be the first step towards building a true space-based human civilisation is still an open question. The US plan includes a permanent lunar base with a place for international partners, to be used for exploration, technology development and science. For the safety of all involved it would be best if more than one nation were to have a system that could take people to and from the moon's surface. It may even turn out that the best way to go back and forth is to fly commercial. ?