Scientists recently discovered that there is a planet circling Alpha Centauri, the closest star in our galaxy. These two intriguing neighbors of ours are only 4.3 light years away (a mere 25 trillion miles). The planet is in Alpha Centauri’s habitable zone. That means it may have water, which means it may have life. That’s a very compelling reason to go there some day. Human beings need to explore. Some day we may need to escape from Mother Earth.
The problem is that with our most powerful current rocket engines it would take more than 30,000 years to get there. The best candidate on the drawing board for a revolutionary new propulsion system is antimatter propulsion. The imaginary starship Enterprise has an antimatter propulsion system. You can learn about it here: https://www.space.com/21201-star-trek-technology-explained-…
The concept of antimatter began to be discussed by physicists over a hundred years ago. It was finally described mathematically by the physicist Paul Dirac in 1928 and three years later the first antimatter particles were actually produced in a laboratory.
The neat thing about antimatter is that when it contacts normal matter the two types of matter are instantly “annihilated” and in the process they release a tremendous amount of energy. A gram of antimatter (about the size of an M&M) has the equivalent energy of an 80 megaton nuclear bomb.
The biggest challenges with antimatter propulsion are:
– It takes a tremendous amount of energy to generate antimatter particles. So far scientists have produced only small amounts of antimatter, nowhere near enough to propel a spaceship, assuming you have solved the other big problems.
– It’s extremely difficult to store antimatter, because of that little annihilation problem. In 2010 an international scientific team successfully created and briefly stored a tiny amount of antimatter, using hydrogen atoms as the source and using a magnetic field to isolate the antimatter from the walls of the container. A later experiment in 2015 managed to store an antimatter particle for an astounding 400 days.
– It’s difficult to direct the energy out the tail end of the spacecraft, in order to move it forward. To get to Mars, for example, the antimatter engine will have to push positrons (antimatter particles) out the back end of the spacecraft at a rate of 10 to the 15th power per second.
A small company called Positron Dynamics in Livermore, California, believes they have solved these problems. They are on the verge of building the first antimatter space propulsion system. The company is led by Dr. Ryan Weed, a PhD physicist and a former Air Force test pilot. They are building a miniature spacecraft about the size of a shoe box. Here is a description of their approach, from their web site: “Our core innovation is the ability to generate intense beams of cold positrons using proprietary array moderators combined with compact radioisotope sources of positrons.”
They are part of a revolutionary change that’s occurring in the space business. It’s called Cube Sats – miniature spacecraft about the size of a Rubik’s Cube and larger. This new approach is providing affordable access to space for developers of space applications all over the world including hundreds of small innovative companies and university teams.
Cube Sats are so small that they can piggyback on a larger satellite launch. After the larger satellite is in orbit a little door opens and out pops the Cube Sat. Then it unfolds its paper-thin solar panels and goes online. Cube Sats can also be launched into space by one of several private space launch companies around the world that are now operating routinely at a much lower cost than traditional large government-funded rockets. The business of space access has been transformed by Cube Sats and low cost launch services.
Some of the initial low Earth orbit applications for Cube Sats are Internet access for remote and less developed populations (only about half of the world’s population has Internet access), Earth imaging (such as monitoring crops and tracking trucks and ships), and various military applications. Future applications include mining asteroids for water and minerals (yup, we’re gonna need that). You can learn more about Cube Sats here: https://youtu.be/Z2wWgedLBk4
During my time in the IT department at the Lockheed Martin Skunk Works I learned that great ideas come from inspired individuals and great accomplishments come from inspired teams. Dr. Weed, like Kelly Johnson and Ben Rich and other great Skunk Works leaders, is one of those inspired individuals and his company, Positron Dynamics, like the Skunk Works, is one of those inspired teams.
You can listen to Dr. Weed describe his dream here: https://youtu.be/EBebWBjpWIQ
Stories for All Ages 
2 thoughts on “Antimatter Propulsion”