“We don’t need warp drive or worm holes to reach the stars – we just need to use the known laws of physics and think big,” says Les Johnson of NASA’s Advanced Concepts Office.
“There are ways, in known physics, that will enable us to go from here to other stars, but in order to do that, we have to think differently," he said. "We have to start thinking big. And I mean really big.”
Johnson’s suggestions included a “solar sail” the size of Nevada - and spaceships where generations would live and die on huge craft travelling between star systems.
Johnson, a popular science author, was speaking a conference for the sci-fi game EVE, where humanity traverses the galaxy via wormholes and stargates. Johnson said that the real version would be rather more time-consuming, and require a new kind of thinking.
“To go to the stars we have to engineer things on massive scales,” he says.
Johnson says that any starship would require generations of crew that would live and die on board, and be vast in scale. “If our spacecraft could travel at 10% of the speed of light, which currently isn’t possible, it would take 44 years to get to our nearest star,” he said.
He said that such big ideas weren’t unknown in history - generations lived and died building the pyramids, or some of Europe’s great cathedrals.
Discussing the idea of solar sails - where huge “sheets” would propel craft using energy from stars, he said, “You’ll need a sail the size of Nevada with a laser that has the energy output of roughly equivalent to the energy output of the human race today.”
Johnson says this might be possible within 100 years. He voiced the hope that “unknown physics” such as wormholes might offer a helping hand, but said that engineers should focus on known physics, just at a different scale
“The laws of physics don’t say that interstellar travel is impossible; it is simply very difficult. In the past, this was viewed as a challenge. We’ve smashed atoms, covered continents with roads, explored the most inhospitable places on Earth, and sent people to the Moon and robots to the edge of the solar system. But that was yesterday. What about tomorrow?,” Johnson asks.
Planning for the future is something engineers already do, he points out. “The Hoover Dam was built in the 1930s, but the design life of the dam is 2,000 years. We need that foresight if we are ever going to the stars.”
“Now this is where we need to think differently — to go to the stars with these systems/ These may sound like science fiction ideas, but, fundamentally, no physical laws are being broken. What’s more, who knows what technologies and energy-generation systems we’ll have access to in 100 years time?”
“We just need to think really, really big and long-term. This is something we’re not used to doing.”
NASA already has plans for a deep-space solar sail mission, Sunjammer, planned for this decade.
Spacecraft with “solar sails” may be the first to venture beyond our solar system - but others rely on nuclear fusion, harnessing the energy of the hydrogen bomb, much like Star Trek’s “Impulse Drive”, which the Enterprise uses to steer through solar systems.
Dr Rob Adams, speaking at the Icarus Interstellar conference in Las Vegas this year says that the technology is feasible now, “We just have to make something blow up. There are very facilities working on this right now. We’ve looked at models where we could get to Mars in three months and actually stop there.”
Johnson - who worked on previous concepts for interstellar craft, such as the Daedalus starship, says that any attempt to travel to the stars will require big thinking.
“The original Daedalus starship would weigh in at a whopping 54,000 tons, where only 450 tons of that mass would be payload; the rest would be fuel. That vehicle would therefore dwarf the Empire State Building.”
“Humanity is on a path that can take us to the stars – if we don’t stop dreaming big and taking chances,” he said.