[♪ INTRO].

It happens all the time in Star Trek and other science fiction shows:. At the press of a button, a starship is able to whiz right past the speed of light, off to explore strange new worlds.

Of course, thanks to the laws of physics, real life isn’t quite as fun, because nothing can go faster than the speed of light. Even Voyager 1, the fastest thing we’ve ever sent out of the solar system, would take more than 17,000 years to travel one measly light-year. Still, that has not stopped engineers from dreaming of ways to explore other worlds.

Many ideas have come and gone, but one of the most ambitious and influential was Project Daedalus. It was thought up in the 1970s, and it proposed a way we could get to a star almost six light-years away... in less than 50 years. Project Daedalus was conceived by the British Interplanetary Society, a group founded in the 1930s, long before we’d launched anything into space.

Their first project was designing a concept for a moon rocket, and later, they also studied how we could use German missiles for human spaceflight. Admittedly, they didn’t by any stretch have the resources to build these spacecraft themselves. Instead, it was a group of academics and engineers trying to study, on paper, the feasibility of such a mission using present or near-future technology.

Maybe another group would someday be interested in the building part. Still, if nothing else, this team did have ambition. They began Project Daedalus in 1973 and published their final plan only five years later.

Their goal was to get a robotic, uncrewed spaceship to around 12% the speed of light, or about 36,000 kilometers per second, and send it to study a target called Barnard’s Star. This star is about six light-years away, so it isn’t the closest one to Earth. But at the time, astronomers thought it had something no other nearby star did: planets.

Specifically, two of them, which had supposedly been discovered in the 1960s. After accelerating to its max speed, Daedalus would be able to get there in only 50 years, well within the span of a human lifetime. Instead of relying on future inventions, the group wanted to use only contemporary or near future technology to propel their spacecraft.

So instead of waiting around for something like an antimatter engine, they settled on nuclear explosions. As you do. Their proposed design was a sort of odd, bubbly-looking thing, essentially, a rocket with a belt of round nukes in the middle.

The idea was to create a series of small nuclear explosions to build up momentum for the craft. Each explosion would accelerate it more and more over the course of about five years, until it reached those incredible speeds. Although this nuclear stuff was an extreme idea, it wasn’t an especially new one.

Across the pond, NASA had long been pursuing nuclear propulsion technology, including with Project Orion, in the 1950s and ‘60s. But that program was shut down by nuclear treaties. Thankfully, Daedalus only proposed using coin-sized pellets instead of full-on nuclear bombs like NASA, so their engine might not have been a problem if anyone ever wanted to build this ship.

But that didn’t mean Daedalus didn’t have other issues. For one, even though it used nukes instead of heavy, conventional fuel, the ship alone would still have weighed about 2400 metric tons, which is 18 times bigger than the largest payload ever carried to orbit. Also, as the engineers soon realized, conventional nukes wouldn’t even be enough:.

In order to have enough fuel and power, they’d actually need fusion. This process involves synthesizing two elements into a heavier one, then utilizing the excess energy. But we don’t even have efficient fusion technology today.

So, like antimatter engines, this tech was part of the “not coming any time soon” category. Even if the Daedalus team had managed to get all that sorted out, though, there would have been even more issues once the mission was underway. Like, the farther the craft got from Earth, the harder it would be to communicate with it.

And any repairs would be almost impossible without fairly advanced artificial intelligence, which definitely wasn’t a thing in the 1970s. Oh, and, one small detail, the news also broke partway through the Daedalus study that. Barnard’s Star didn’t actually have planets.

These were false signals created by routine telescope maintenance. So, the odds of ever making this mission a reality kind of plummeted. It became a dream for the far future and, eventually, faded from the popular imagination.

Of course this doesn’t mean we’re done exploring the galaxy, though. These days, a mission like Project Daedalus might actually be close to possible. Or at least, closer.

Some groups are still looking into nuclear propulsion, including NASA, which has been exploring how to use nuclear rockets in the solar system without violating any treaties. And work on spaceship repair and robots has really improved, too. In 2015, the University of Michigan created a self-healing material that could plug small holes in spacecraft.

And the International Space Station has also tested out a few robots that could take care of onboard repairs. Admittedly, there’s still a long way to go, but visiting other stars does feel less impossible now. And if nothing else, engineers are also exploring tons of alternative options to explore the galaxy.

Like, there’s one called Breakthrough Starshot, which would use hundreds of simple, laser-powered probes to reach our neighboring star, Alpha Centauri, within 20 years. But whatever happens, our thoughts are clearly aimed at the stars. Now we just need to figure out a way to get to them, whether it’s nukes, lasers, or something even weirder.

Thanks for watching this episode of SciShow Space! Along with Project Daedalus, there are plenty of other missions that never made it off the ground. You can learn more about some of them in our episode with Reid about three history-changing missions. [♪ OUTRO].