April 13, 2024

Netflix’s ‘3-Body Problem’ Reveals a Surprisingly Brilliant Mode of Space Travel

In 1946, just a year after the explosive and devastating debut of the nuclear age, Polish-American mathematician and physicist Stanislaw Ulam had an idea for a rocket that was so crazy it might work.

During the war, Ulam worked side by side with Robert Oppenheimer and Edward Teller in creating the atomic bomb at Los Alamos, and now that peace had been achieved, the future of the nuclear age was just beginning. It was during this moment of possibility, while still conducting research at the famous New Mexico facility, that Ulam’s thoughts turned to the stars: Could the explosive power of the atomic bomb be used for exploration rather than destruction?

In other words, could nuclear bombs somehow become rocket engines for deep space?

“It is a very ambitious but efficient way of carrying out space exploration with a vehicle capable of traveling at high speeds with high payloads and an extremely good ratio of payload to total initial weight,” Ulam wrote in his 1976 memoir. Adventures of a mathematician. “The spacecraft could carry hundreds or thousands of people.”

Earthlings want to send a probe light years away to spy on San-Ti, but they need an idea to get there quickly.

Fast forward to 2024, and Ulam’s nuclear reverie is enjoying something of a renaissance as the Netflix series The three-body problem, based on a novel by Chinese science fiction author Liu Cixin, sees the idea as a quick and not-so-easy way to propel a payload to incredible speeds. To achieve this, the characters invent a “radiation candle” to be propelled by a thousand consecutive nuclear explosions into space until the spacecraft reaches a speed just above 1% of the speed of light.

But while the Three-Body Problem uses Ulam’s nuclear rocket for decidedly science fiction purposes, the 80-year history of this developing technology, known today as nuclear pulse propulsion (NPP), is very real – and can yet be the future of space exploration.

An explosive story

Every rocket humanity has ever sent into the sky has been powered by chemical fuel, a combination of kerosene, oxygen and hydrogen, or both, with enough “energy” to escape Earth’s orbit and reach its otherworldly destination. This is how the Apollo astronauts landed on the Moon, how the space shuttle crews built the International Space Station, and how future space explorers will lay footprints on Mars.

But similar to how fission (and especially fusion) represent efficient energy sources of the future, the same can also be said of rockets. And while the idea of ​​harnessing the blunt blasts of a nuclear bomb may seem strange, the idea isn’t as strange as you might think.

“Your car is a pulsed system because the piston compresses gas and air together and then explodes and separates the piston,” said Jason Cassibry, professor in the Department of Mechanical and Aerospace Engineering at the University of Alabama in Huntsville. Inverse. Cassibry is affiliated with the university’s Propulsion Research Center, where he recently worked on a pulsed propulsion system similar to magneto-inertial fusion technology. “So every time you explode [a bomb] According to Newton’s second law, this would increase momentum and accelerate it, just like you would do when driving your car and stepping on the gas.”

NASA’s Project Orion involves a heavy-lift vehicle that used atomic bombs to detonate behind a pusher plate equipped with shock absorbers.

Ulam recognized the beautiful simplicity of a pulsed system and, after mulling over the idea for years, finally put his thoughts on paper in a confidential 1955 report, stating that “the scheme proposed in the present report involves the use of a series of devices disposable. reactors (fission bombs) ejected and detonated at a considerable distance from the vehicle.” Ulam eventually presented the idea to President Eisenhower’s science adviser, George Kistiakowsky, whose “reception was not enthusiastic,” Ulam wrote in his memoirs.

Despite initial skepticism, the idea eventually gained traction under the infamous Project Orion, a heavy-lift vehicle concept that used atomic bombs, ranging from a few to several kilotons, to detonate behind a pusher plate equipped with shock absorbers to limit the impact of that bomb. . initial and explosive acceleration. Although many of the spacecraft’s early design challenges were overcome, the project was terminated in 1965 due to nuclear treaties prohibiting nuclear explosions in space. Chemical rockets also became more powerful and were clearly NASA’s preferred vehicle to the stars during the Space Race.

But the idea did not die and several projects carried the NPP flame with names such as Project Daedelus, Project Longshot and Vista. One of the most intriguing ideas was a spacecraft concept known as Medusa, which altered the design of pulsed propulsion by using a light sail (technically a balloon) to harness the pressure pulses of subsequent nuclear explosions, a concept extremely similar to that explored in the Three-Body Problem. Unfortunately, none of these concepts – including Cassibry’s Pulsed Fission-Fusion (PuFF) system – have reached the launch pad, largely due to technological limitations and lingering concerns about detonating nuclear explosions in space.

“There was a resurrection of Project Orion in the 1990s when Clinton was in office, and when they got down to the level of talking to some of his staff…they said ‘there’s no way we’re putting nuclear weapons in space,’” says Cassibry. “Now, they are even more sensitive to this – even though the Cold War is over, there are still concerns.”

Space travel goes nuclear

However, not all nuclear propulsion systems are created equal.

While Cassibry worked on pulsed systems, apparently the great-grandchild of Ulam’s original vision, other systems include nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP). While all three are based on nuclear technology, NTP and NEP use more traditional fission systems (i.e., heating the propellant, which turns into gas and results in propulsion). Thus, unlike the NPP, which uses microexplosions for propulsion (much to the chagrin of international nuclear treaties), the NTP and NEP systems cannot be weaponized.

Although all three technologies use different methods and have various use cases, nuclear propulsion – whether through fission heating or nuclear explosion – has some pretty marked advantages over its chemical competitor.

“There are certain missions to the ice giants – Uranus and Neptune – that could not be done, given all the constraints you place on a mission that far away, with anything other than nuclear thermal,” says Cassibry. “[NTP] It’s simpler than some of the things we could do… It’s kind of low-hanging fruit in terms of advanced propulsion concepts.”

NASA has taken notice and hopes to test its NTP Demonstration Rocket for Agile Cislunar Operations (DRACO) in 2026. Being three times more efficient than chemical rockets, this means Draco could travel from Earth to Mars in just 45 days or carry larger payloads. . loads in a more conventional term. However, Cassibry still believes that nuclear pulse propulsion, using fission, fusion or a combination of the two, will eventually surpass even these nuclear-powered spacecraft decades from now.

“There’s a joke that crushes my soul whenever I hear that fusion is the technology of the future and always will be,” says Cassibry. “But we started with a lot, a lot, really terrible reactors and we have made steady progress… we will see fusion propulsion possible within 20 to 30 years.”

Whether it’s on a popular Netflix show or in the minds of space travel’s top minds, it appears Ulam’s dream is alive and well.

Leave a Reply

Your email address will not be published. Required fields are marked *