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Just 10 grams of antiprotons could provide enough energy to propel a manned spacecraft to Mars within a month. In contrast, an unmanned mission takes just under a year to make the journey. Adastra / Getty Images"Engineering, prepare for warp drive." With this signal, the crew of the U.S.S. Enterprise from "Star Trek" readied to propel the ship through space at faster-than-light speeds.
Warp drive is one of the science-fiction ideas, alongside teleportation and time travel, that holds some theoretical foundation. While we haven't achieved it yet, researchers are making strides toward developing an interstellar engine resembling the antimatter propulsion system seen in the Enterprise.
Antimatter-powered spacecraft, like the one shown here, could one day reduce the travel time to Mars from 11 months to just one month. Explore current space travel technology through these images of space shuttles.
Photo courtesy NASAWhile no engine is likely to exceed the speed of light, the laws of physics currently prevent such travel, we can still achieve speeds far beyond what current propulsion systems allow. A matter-antimatter engine could propel us beyond our solar system and allow us to reach nearby stars much faster than spacecraft powered by a liquid-hydrogen engine, such as the ones used in space shuttles.
It's similar to the comparison between driving an Indy race car and a 1971 Ford Pinto: The Pinto will eventually reach the destination, but it'll take 10 times longer than the Indy car.
Let’s look ahead a few decades to envision the future of space travel, exploring antimatter spacecraft and discovering what antimatter is and how we might use it for advanced propulsion systems.
What is Antimatter?
This composite image of the Crab Nebula shows matter and antimatter being accelerated close to the speed of light by the Crab pulsar. These stunning images were captured by NASA's Chandra X-ray Observatory and the Hubble Space Telescope.
Photo by NASA/Getty ImagesThis isn't a trick question. Antimatter is precisely what it sounds like — the inverse of regular matter, which makes up most of the universe. For a long time, scientists believed that antimatter was merely a theoretical concept in the cosmos.
British physicist Paul Dirac played a crucial role in reshaping our understanding of antimatter.
In 1928, Dirac modified Einstein's iconic equation E = mc². He proposed that Einstein did not account for the possibility that the "m" in the equation — mass — could have both positive and negative energy. Dirac's revised equation (E = + or - mc²) paved the way for the existence of anti-particles. Since then, multiple anti-particles have been observed by scientists.
Antimatter Particles In Action
Anti-particles are essentially the mirror counterparts of normal matter. Each anti-particle has the same mass as its corresponding particle, but the charges are reversed. Below are some key antimatter discoveries from the 20th century:
- Positrons: Electrons that carry a positive charge instead of the usual negative charge. Discovered by Carl Anderson in 1932, positrons were the first indication that antimatter exists.
- Anti-protons: Protons with a negative charge, rather than the typical positive charge. In 1955, researchers at the Berkeley Bevatron produced an antiproton.
- Anti-atoms: By pairing positrons with antiprotons, scientists at CERN, the European Organization for Nuclear Research, created the first anti-atom. They successfully created nine anti-hydrogen atoms, each lasting only 40 nanoseconds. By 1998, CERN had ramped up production to 2,000 anti-hydrogen atoms per hour.
When antimatter comes into contact with normal matter, these opposite particles collide, resulting in an explosion that emits pure radiation, traveling outward at the speed of light. Both particles involved in the collision are annihilated, leaving behind other subatomic particles.
The explosion that occurs when matter and antimatter collide converts the total mass of both objects into energy. Scientists believe that this energy is far more powerful than any generated by other forms of propulsion.
Antimatter in the Cosmos
Gamma rays and cosmic rays are high-energy particles and radiation that originate from various cosmic phenomena, such as supernovae, black holes, and even the Big Bang itself. Scientists hypothesize that antimatter should have been as abundant as ordinary matter because of the Big Bang, yet it remains rarely detected in our universe.
The Role of Particle Detectors
Particle detectors are crucial tools in particle physics, enabling scientists to identify and examine subatomic particles, including antimatter, as they interact with normal matter. By tracking and analyzing these interactions, detectors allow scientists to better understand fundamental particle properties and explore the origins of the universe.
So Why No Matter-Antimatter Reaction Engine?
The challenge in creating an antimatter propulsion system is the scarcity of antimatter in the universe. If matter and antimatter were equally abundant, we would likely witness these reactions happening around us. Since antimatter is not present in our environment, we don't see the radiant light that would occur from its collision with matter.
At the time of the Big Bang, it is theorized that particles may have outnumbered anti-particles. As previously mentioned, when particles and anti-particles collide, they annihilate each other. If there were initially more particles in the universe, they would have survived, leaving no naturally occurring anti-particles in existence today.
In 1977, scientists detected a possible antimatter deposit near the center of our galaxy. If confirmed, this would indicate that antimatter is naturally occurring, eliminating the need for artificial production.
Currently, we must generate all antimatter ourselves. Fortunately, we have the technology to produce antimatter using high-energy particle colliders, also known as 'atom smashers.'
Atom smashers, like CERN, are massive tunnels equipped with powerful supermagnets, which accelerate atoms to nearly the speed of light. When an atom travels through the accelerator, it collides with a target, creating new particles, some of which are antiparticles, which are then isolated using magnetic fields.
These high-energy particle accelerators can only produce tiny amounts of antimatter each year—about one or two picograms. A picogram is one trillionth of a gram. The total amount of antiprotons produced by CERN in a year would only be sufficient to power a 100-watt light bulb for three seconds. It would take enormous quantities of antiprotons to travel to distant stars.
Matter-Antimatter Engine
The concept of antimatter spacecraft, like the one illustrated here, could potentially enable us to travel far beyond the solar system at unprecedented speeds.
Image courtesy of the Laboratory for Energetic Particle Science at Penn State UniversityNASA is perhaps only a few decades away from creating an antimatter spacecraft that could drastically reduce fuel costs. In October 2000, scientists at NASA unveiled early designs for an antimatter engine that could produce immense thrust with only tiny quantities of antimatter. According to a report in the Journal of Propulsion and Power, the antimatter required to power the engine for a year-long journey to Mars could be as small as one-millionth of a gram.
Matter-antimatter propulsion would be the most efficient form of propulsion ever developed, as it converts 100 percent of the mass of both matter and antimatter into energy. The collision of matter and antimatter releases energy from their annihilation, which is approximately 10 billion times more powerful than the chemical energy generated by hydrogen and oxygen combustion, such as that used in the space shuttle.
Matter-antimatter reactions are 1,000 times more powerful than the nuclear fission used in nuclear power plants and 300 times more powerful than the energy produced by nuclear fusion. This means matter-antimatter engines have the potential to take us further using much less fuel. However, the challenge lies in producing and storing antimatter. A matter-antimatter engine requires three essential components:
- Magnetic storage rings: To prevent antimatter from coming into contact with normal matter, it is contained in storage rings with magnetic fields that guide the antimatter around the ring until it is ready to be used to generate energy.
- Feed system: When additional power is required, the antimatter will be released to collide with a matter target, triggering an energy release.
- Magnetic rocket nozzle thruster: Similar to a particle collider on Earth, a long magnetic nozzle will direct the energy produced by the matter-antimatter interaction through a thruster.
The spacecraft's storage rings are designed to hold the antimatter in place until needed.
Image courtesy of the Laboratory for Energetic Particle Science at Penn State UniversityAround 10 grams of antiprotons would be sufficient to power a manned spacecraft on a one-month journey to Mars. Currently, it takes just under a year for an unmanned spacecraft to reach Mars. For example, the Mars Global Surveyor took 11 months to get to Mars in 1996.
Experts believe that the speed of a matter-antimatter powered spacecraft would enable humans to travel to destinations previously unreachable in space. Journeys to Jupiter and even beyond the heliopause—where the Sun's radiation ceases—would be within our reach. However, it will still be quite some time before astronauts are requesting warp speed from their starship's helmsman.
