Going to the Moon is hard. And expensive. It took Nasa the equivalent of four million human-years to put twelve astronauts on the surface, at a cost of some $25 billion.
It is one of the reasons that ever since the Apollo 17 crew packed up their kit and flew home, we have not been back.
But, there now seems to be a renewed appetite for returning to the Moon. The Golden Spike Company recently announced that it can take you there by 2020 for $1.4 billion and we can only guess how much money China is putting into its lunar ambitions.
So, assuming you have the cash, what else do you need to get to the Moon? Here is BBC Future’s seven-step guide for any individual, nation or company wanting to take a giant leap:
A new rocket
Escaping the Earth’s gravity and getting people (and hardware) to the Moon requires a lot of energy. The 1960s solution, the Saturn V rocket, was a staggering piece of technology. Standing 30 stories high, the three-stage launcher was fitted with more than three million parts. But laying your hands on one may prove difficult. The only remaining Saturn V made up of original hardware intended for space, is in a giant shed in Houston. Nasa might notice if anyone tried to borrow it. And what was left of the failed Russian equivalent, the N1, has been made into bus shelters at the Baikonur Cosmodrome in Kazakhstan.
Given that there is no modern equivalent of the Saturn V or N1, and short of building a similarly massive rocket, you will need a plan B. Golden Spike proposes a multi-stage approach with multiple launches of smaller rockets (such as the Atlas 5) to ferry a lunar lander, crew capsule and two Lunar Transport Vehicles (LTV) into orbit. The LTVs will provide the power to take the lander and crew capsule from the Earth to the Moon.
Alternatively, you might choose to launch several sections of your spacecraft into Earth orbit, assemble them there and then fly onto the Moon. The various components could be launched on anything from a European Ariane to a SpaceX Falcon. But you could only fly your crew on a rocket certified for human spaceflight such as a Russian Soyuz or Chinese Long March.
Another way might be to use bigger rockets – or add new stages to existing rockets – to place your component parts into lunar orbit, and put the whole mission together there. Nasa is also developing a new heavy-lift rocket, the Space Launch System, which is slowly moving from the drawing board to the factory but the first tests aren’t scheduled until 2017.
Whatever you choose, the good news is that most of the technology is available and is coming down in price as private companies begin to offer alternatives.
You may think that once the rocket is sorted, you are most of the way there. But that is only going to boost you into orbit. Once in space you need something to ferry you towards the Moon and land on its surface.
When they were designing Apollo in the early 1960s, Nasa engineers quickly realised that it made more sense to have two separate vehicles – an orbiter and a Moon lander – rather than a single spacecraft.
The 21st Century equivalent of the Apollo capsule is Nasa’s Orion module. It resembles a super-sized Apollo and the first test versions of this “deep space” capsule are now nearly complete. However, it will be several years before it’s ready for any crew.