Interstellar travel is something humanity has only achieved in science fiction, such as the USS Enterprise in Star Trek, which uses antimatter engines to travel through star systems. But antimatter isn’t just a science fiction trope. There is antimatter.

Elon Musk has described the power of antimatter as “a ticket to interstellar travel,” and physicists like Ryan Weed are exploring how to harness it. Antimatter consists of particles that are nearly identical to ordinary matter but have the opposite electrical charge. This means that antimatter will both annihilate and produce enormous amounts of energy when it comes into contact with normal matter.

“The destruction of antimatter and matter directly converts mass into energy,” Weed, co-founder and CEO of Positron Dynamics, a company working to develop an antimatter propulsion system, told Business Insider. Just one gram of antimatter can cause an explosion equivalent to a nuclear bomb. Some say it’s this kind of energy that can boldly take us where no one has gone before at record speed.

Space travel at record speed

The advantage of all this energy is that it can be used to accelerate or slow down the spacecraft to very high speeds. For example, let’s go to Proxima, our nearest star system, which is about 4.2 light-years away.

Weed said in 2016 that an antimatter-based engine could theoretically accelerate a spacecraft up to 1g (9.8 square meters per second) and get us to Proxima in just five years. That’s 8,000 times faster than Voyager 1, one of the fastest spacecraft in history, covering about half the distance, according to NASA. Even in our own solar system, an antimatter-powered spacecraft could reach Pluto in 3.5 weeks, while NASA’s New Horizons probe took 9.5 years to reach it, Weed said.

Why don’t we have antimatter engines?

The reason we don’t have antimatter engines, despite their enormous potential, is not engineering but cost. Accelerator physicist Gerald Jackson, who works on antimatter projects at Fermilab, told Forbes in 2016 that with enough funding, we could have an antimatter spacecraft prototype within a decade. There are basic technologies. Armed with the world’s most powerful particle accelerators, physicists have created antiprotons and antihydrogen atoms.

The truth is that this type of antimatter is incredibly expensive to produce. It is considered the most expensive substance in the world. Jackson gave us an idea of ​​how much it would cost to build and maintain an antimatter machine. Jackson is the founder, chairman and CEO of Hbar Technologies, which is working on an antimatter space sail concept that would slow down spacecraft traveling at 1 to 10 percent of the speed of light; A useful design for orbiting a distant star, a planet. or select the month you want to read.

Jackson said he has developed an asymmetric proton collider that can produce 20 grams of antimatter per year.

“For a 10-kilogram science package traveling at 2% of the speed of light, 35 grams of antimatter would be required to slow the spacecraft and place it into orbit around Proxima Centauri,” Jackson told BI.

According to him, the construction of a solar power plant that will meet the enormous energy needs of antimatter production will cost 8 billion US dollars and its operation will cost 670 million dollars per year. The idea is so far. “There is currently no significant funding for advanced space propulsion concepts,” Jackson said. But there are other ways to obtain antimatter. This was where Weed focused his work.

Weed’s concept involves positrons, the antimatter version of the electron.

Another type of antimatter engine

Positrons “are several thousand times lighter than antiprotons and do not have as strong an annihilation force,” Weed said. But the advantage is that they occur naturally and do not require a giant accelerator and billions of dollars to create them.

Weed’s antimatter propulsion system is designed to use krypton-79, a form of the element krypton that naturally emits positrons. The propulsion system will first collect high-energy positrons from krypton-79 and then direct them into the ordinary matter layer, producing annihilation energy. This energy will then trigger a powerful fusion reaction that will create thrust for the spacecraft.

Although positrons are cheaper to produce than stronger forms of antimatter, they are difficult to use because they are high energy and require deceleration or “deceleration”. Creating a prototype to test in space is still out of reach cost-wise, Weed said. This is true for all antimatter engine designs. Over the decades, scientists have proposed dozens of concepts, but none of them have been implemented.

For example, in 1953, Austrian physicist Eugen Zenger proposed a “photon rocket” that would operate on positron annihilation energy. And since the 1980s, there has been talk of antimatter thermal engines that would use antimatter to heat a liquid, gas, or plasma to provide thrust.

“It’s not science fiction, but we won’t see it in flight until there’s a significant ‘mission shot’,” Weed said of the engine concept.

Can it work?

Paul M. Sutter, astrophysicist and host of the Ask an Astronaut podcast, told BI that “the devil is in the engineering details” to build Weed’s concept at the scale of a starship.

“We’re talking about a device that uses really huge amounts of energy and requires perfect balance and control,” Sutter said.

Ultimately, this immense energy is yet another obstacle holding us back from revolutionizing space travel. Physicist Steve Howe, who worked on the antimatter concept with NASA in the 1990s, told BI that “if something goes wrong, there will be these big explosions” during the testing.

“So we need the ability to test high energy density systems that do not threaten the biosphere but still allow us to develop them,” said Howe, who believes the Moon would be a good testing base. “And if something goes wrong, you’ll melt a piece of the Moon, not the Earth,” he added.

Antimatter, as a rule, excites the imagination of everyone who studies it. “But we need crazy but plausible ideas to move into space, so it’s worth considering,” Sutter said.

Wied echoes this sentiment, saying: “Until there is a compelling reason to quickly reach the Kuiper belt, the solar gravitational lens, or Alpha Centauri—or perhaps try to return large asteroids for mining—progress will continue to be slow.” . this region”.