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  • [♪ 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 thenot coming any time sooncategory.

  • 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]

[♪ INTRO]

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B1 中級

神匠計劃:我們1970年代的星際旅行計劃 (Project Daedalus: Our 1970s Plan for Interstellar Travel)

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    林宜悉 發佈於 2021 年 01 月 14 日
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