From science fiction to reality

Since the beginning of human space exploration, only two spacecraft have reached interstellar space (regions outside the solar system).

After the first spacecraft, Voyager 1, launched in 1977, it took more than 30 years for it to cross the boundary interface that scientists believe is the beginning of interstellar space.

The ability to send valuable data back through a medium unaffected by the sun was a remarkable achievement.

But a weakened power supply will make it nearly impossible for Voyager 1 to reach its nearest star, Proxima Centauri, 4.2 light-years away, and the mission will take nearly 73,000 years.

said Les Johnson, a NASA scientist and author of several science and science fiction books. The National It can take 50 to 100 years to reach another star.

“Within the next 50 to 100 years, we may have the technology to send the first robotic spacecraft to another star,” said Johnson, who manages the U.S. Space Agency's interstellar propulsion research project. .

“After considering all known physics-based propulsion systems, and based on the rate of growth in technology, these first probes would be similar to today's solar sails, but with laser light reflecting off the sail. I think it would be propelled to the stars using powerful laser light instead of sunlight.”

Humanity's journey into interstellar space

Laser light sails only work on small spacecraft, so it could take significantly longer for a crewed mission to travel to another star.

Fusion propulsion is a method of powering spacecraft using high-energy particles produced by nuclear fusion reactions, and is necessary to enable manned missions into interstellar space.

“When it comes to humans, it's more complicated because keeping a group of humans alive for anywhere from 10 years to centuries of space travel requires significant mass, and that means huge ships.” Mr. Johnson said.

“Ships manned by humans need at least fusion propulsion, and ideally antimatter.

“We know that these are physically possible, but the level of technology required for interstellar travel seems very far in the future, perhaps 100 to 200 years away.”

Scientists dream of antimatter propulsion that would enable space travel at 70% the speed of light, but fusion propulsion seems much closer to reality.

The technology could also help shorten the time it takes to reach Mars, where most space agencies are sending astronauts.

Laura Folchik, author and founder of space consulting firm Astralytical, said fusion propulsion has the potential to revolutionize spaceflight.

“We won't be able to achieve interstellar travel unless we develop faster and more efficient means of acceleration,” Folchik said.

“We also need to develop long-term, self-sustaining, robust ecosystems for long-distance voyages, and better means of shielding radiation. These advances will take at least a century.”

Developing fusion technology is not easy, but the temperatures required to achieve it are 10 times hotter than the sun, and several companies have been trying for years.

California-based startup Helicity Space recently received $5 million in seed funding to accelerate its fusion propulsion technology project.

UK-based startup Pulsar Fusion is also trying to develop this technology and has started building a large fusion reactor in the UK.

When the engine is ignited, it becomes the hottest place in the solar system, at least temporarily.

China is also moving forward with the development of nuclear fusion, with reports of a new state-owned company that could help accelerate production of an “artificial sun.”

Are there any planets similar to Earth outside our solar system?

One of the reasons scientists want to explore interstellar space is to learn more about the universe and the possibility of life beyond Earth.

NASA has been using telescopes to study exoplanets, or planets outside our solar system, for decades.

“It's doubtful we'll ever find Earth 2.0 anywhere near us,” Johnson said, adding that finding another homelike planet is unlikely in the near future.

“Over time, we might be able to convert other planets to habitable conditions, but that would take centuries or even millennia more,” he says.

“That doesn't mean you shouldn't go. The job of science is to learn more about the universe we live in.

“Studying planets around other stars helps us understand our solar system more deeply and expands our knowledge about this large universe. In my opinion, that alone makes this journey becomes something we should do.”

Updated: February 2, 2024, 9:35am