R oughly 10,000 years ago, people were sitting in their caves, being busy drawing pictures on walls. Over time however, the human species evolved the urge to explore. It took them an awful lot of time to explore their own planet but by the beginning of the 20th Century, technology had evolved and mankind was finally able to defy earth’s gravity.

By the end of the 1960s we sent some of our folks over to the moon. At this time, we had already conquered Venus and Mars with our robotic friends, and missions to the outer Solar System were already on schedule. In 1972, Pioneer 10 passed the asteroid belt between Mars and Jupiter and transmitted the first close-up photographs of the gas giant.

Voyager’s Grand Tour covered the rest of the Solar System. The twin spacecraft mission used a unique constellation of the outer planets (which occurs every 176 years) to travel all the way to the boundaries of the Solar System, visiting all four gas planets. By now, Voyager I is the farthest human-made object from Earth, travelling at an unbelievable velocity of 17 km/s (that’s 61,200 km/h or 0,006% light speed).

The New Horizons probe launched in 2006 is currently on its way to Pluto, for a high speed fly-by, but over all, it has become quiet in interplanetary space travel. It seems, now that we’ve sent probes to all planets, the urge for exploration has come to a hold due to technological limitations.

B etween 1973 and 1978 a group of British scientists worked on a project called Daedalus. The task was to create a spacecraft with near future technology (speaking, technology that will become available some time next century) which was able to travel to Barnard’s star (5.9 light years away) in less than 50 years. The necessary velocity was set to about 12% of the speed of light. Pretty damn fast.

Because speed could not have been achieved with conventional rocket propulsion, they had 2 alternatives at the time: Nuclear fission and Nuclear fusion. They decided to go with fusion, which is as of 2010 still near future technology. They imagined a huge vessel with giant tanks to house all the propellant, which would have had to built in space. Back then they didn’t know about the vast resources of Helium3 on the moon and figured they had to build the spacecraft in orbit around Jupiter.

If we once were to launch such a craft, we better equip it with some failsafe sensors. We can’t afford a camera failure during the few minutes the vessel will speed past the star. It takes a lot of propellant to slow down a spacecraft to normal speed and into an orbit, so we’d probably settle with a quick fly-by. An additional problem caused by such high velocities are even the smallest particles in interstellar space. A 1-gram grain of rock would hit the vessel with the power of 150 metric tons.