NASA’s radical engine concept could reach interstellar space in less than 5 years

A newly proposed propulsion system could theoretically take a heavy spacecraft beyond our solar system in less than 5 years – an feat that took 35 years for the historic Voyager 1 probe to accomplish. The concept, known as the “pellet beam” facility, received a $175,000 NASA grant for further development earlier this year. To be clear, the concept doesn’t currently exist beyond the calculations on paper, so we can’t get too excited yet.

Despite all this, it has caught attention not only because of its potential to take us into interstellar space in a human lifetime – something conventional chemical-fueled rockets can’t – but also for its claims that it can do so with much larger vehicles.

“This proposal addresses a new propulsion architecture for the rapid transit of heavy (1 tonne or more) payloads through the solar system and interstellar medium,” explains Arthur Davoyan, an aerospace engineer at the University of California, Los Angeles.

The cannon beam concept is partially inspired by the Breakthrough Starshot initiative, which runs on a “light sail” propulsion system. The tiny probe using millions of lasers could theoretically reach Proxima Centauri in just 20 years.

The new proposal starts with a similar idea – throwing fuel into the rocket instead of exploding it – but looking at how to make larger objects move. After all, a small probe isn’t what we need if we ever want to independently explore or colonize worlds beyond our solar system.

For the conceptual propulsion system to work, it requires two spaceships, one to interstellar space and the other to orbit around Earth. A spacecraft orbiting the Earth will send a beam of tiny microscopic particles to an interstellar vehicle. These particles will be heated by lasers, causing some to melt into a plasma, which further accelerates the granules, a process known as laser ablation.

These pellets can reach up to 120 km/h (75 mph) and either crash into the sail of an interstellar spacecraft or repel a magnet inside, helping to propel the spacecraft to tremendous speeds that would allow it to blast out of our heliosphere, the bubble. . solar wind around our solar system.

“A pellet beam can reach exoplanets in less than a year, 100 AU in about 3 years, and a solar gravitational lens can reach 500 AU in about 15 years,” says Davoyan.

For context, the AU, which stands for “astronomical unit,” roughly represents the distance between the Earth and the Sun, or about 150 million kilometers (93 million miles). In 2012, it took 35 years for the Voyager 1 probe to pass into interstellar space at a distance of about 122 AU. According to current projections, a 1-tonne pellet beam spacecraft could do the same in less than 5 years.

In February, Davoian explained to Universe Today’s Matt Williams that his team chose the scattering approach rather than using lasers, as with other sailing projects, because scatterings can be propelled by relatively low-power lasers. According to current estimates, only a 10 megawatt laser beam could be used.

“Unlike a laser beam, the pellets don’t disperse as fast, which allows us to accelerate a heavier spacecraft,” Davoyan told Williams.

“Pellets that are much heavier than the funds carry more momentum and can transmit a higher force to the spacecraft.”

Of course, for now, all this is pure speculation. But the first phase of NASA’s Innovative and Advanced Concepts (NIAC) grant will help. This project was one of 14 projects to be funded at this early stage and the next step will be proof-of-concept experiments.

“In the first phase, we will demonstrate the feasibility of the proposed power plant concept by performing detailed simulations of the various subsystems of the proposed power plant architecture and conducting experimental studies to validate the concept,” says Davoyan.