|Above: The view from the tail of a SpaceX rocket, as it leaves Earth for the GEO belt of satellites.
Getting to space, through Earth's thick atmosphere and gravity... that's hard work. To do it we use massively powerful, massively expensive, rockets. Which get used once, and then allowed to crash or burn up in Earth's atmosphere.
Why? We wouldn't drive like that, throwing away a car after every trip, so why fly into space that way?
The truth is it all comes down to money: To reach space you have to fly so fast, and so high, that bringing the rocket back to Earth in fit state for re-use means building a much stronger rocket, and giving it more fuel. For the amount of industry there is in space the expense in building a re-usable, rocket just didn't seem worth it.
Until the turn of the millennium, when a change in viewpoint started to grow in the space industry: What if that expensive re-usable rocket was the thing that was missing to stimulate bigger economic growth in space? At the same time there were revolutions in space flight that fed into this:
- In unmanned space flight there was a steady rise in miniaturisation. Miniature space craft sophisticated enough to carry out meaningful missions at a fraanction of the cost of a full sized satellites, like the well known cubesats, became more and more common.
- In manned spaceflight the idea of private manned missions - known colloquially as space tourism - has been growing.
Both are being taken as signals that there could be more opportunities in space, opportunities a low cost route up there could realise.
Which is where companies like SpaceX, and their successful re-flight of an already flown booster, come in. SpaceX aren't the only ones with a novel idea for a cheap launcher - but as the pictures and video of last week's launch (available here) show, they probably have the most spectacular...
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