Nuclear rockets can go to Mars in half the time – but designing the reactors to power them is not easy.

NASA plans to send crews to Mars within the next decade — but the 140 million mile (225 million km) journey to the red planet could take months to years.

This relatively long transit time is a result of the use of conventional chemical rocket fuel. An alternative technology to chemically powered rockets that the facility is currently developing is nuclear thermal propulsion, which uses nuclear explosions and could one day propel a rocket that makes the journey by half time.

Nuclear fission involves harvesting the incredible energy released when an atom is split apart by a neutron. This reaction is known as a “fission reaction”. Fission technology is well-established in power generation and nuclear-powered submarines, and its application to propel or power a rocket could one day provide NASA with a faster, more powerful way to than chemically powered rockets.

NASA and the National Defense Projects Agency have teamed up to develop NTP technology. They plan to deploy and demonstrate the capabilities of a prototype system in space by 2027 – potentially making it the first of its kind to be built and operated by the US.

Nuclear thermal power could also one day use a space-portable force that would protect American satellites in and out of Earth’s orbit. But technology is moving forward.

He is an associate professor of nuclear engineering at the Georgia Institute of Technology whose research group builds models and simulations to improve and improve the design of nuclear reactors. My hope and desire is to help design a nuclear thermal engine that will carry a manned mission to Mars.

Nuclear versus chemical impact

Common chemical transport methods use a chemical mixture that includes a light source, such as hydrogen, and an oxidizer. When combined, the two ignite, causing the propellant to rapidly exit the nozzle to propel the rocket.

These systems do not require any kind of fire control system, so they are reliable. But these rockets must carry oxygen into space, which can weigh them down. Unlike chemical systems that conduct heat, nuclear thermal systems rely on nuclear reactions to heat electricity that is then emitted from the nozzle to create propulsion or propulsion.

In most fission processes, researchers send neutrons to the lightest isotope of uranium, uranium-235. Uranium absorbs a neutron, forming uranium-236. The uranium-236 then splits into two pieces – fission products – and the reaction releases different particles.

https://www.youtube.com/watch?v=D91T-B-PVE0

More than 400 nuclear reactors in operation worldwide currently use nuclear fission technology. Most of these active nuclear reactors are light water heaters. These fission reactors use water to slow down neutrons and absorb and transfer heat. The water can be steamed directly in the center or through a steam generator, which drives a turbine to produce electricity.

Nuclear heating systems work in a similar way, but use a different type of nuclear fuel that contains more uranium-235. They also work at very high temperatures, which makes them very strong and compact. A nuclear heating system has about 10 times more energy than a traditional light water heater.

Nuclear propulsion can have a chemical leg for several reasons.

A nuclear blast would expel the explosive from the nozzle of the engine very quickly, and produce a great deal of power. This high efficiency allows the rocket to accelerate rapidly.

These systems also have a high specific impact. Specific thrust measures how efficiently the propellant is used to produce thrust. Nuclear propulsion systems have almost twice the impact of chemical rockets, which means they can reduce travel time by a factor of 2.

The history of nuclear fusion

For decades, the US government has funded the development of heat transfer nuclear technology. Between 1955 and 1973, the NASA, General Electric and Argonne National Laboratories programs developed and tested 20 nuclear reactors on the ground.

But these pre-1973 designs relied on highly enriched uranium fuel. These fuels are no longer used due to proliferation risks, or risks associated with the proliferation of nuclear materials and technology.

The Global Threat Reduction Initiative, launched by the Department of Energy and the National Nuclear Security Administration, aims to convert many research reactors that use highly enriched uranium fuel to highly enriched uranium, which low-fat, or HALEU, fat.

High-enriched, low-enriched uranium fuel has fewer components capable of undergoing a fission reaction, compared to highly enriched uranium fuel. So, rockets need to load more HALEU fuel, which makes the engine heavier. To solve this problem, researchers are looking for special materials that can use fuel efficiently in these reactors.

NASA and DARPA’s Demonstration Rocket for Agile Cislunar Operations, or DRACO, program aims to use highly enriched, low-energy uranium fuel in its nuclear engine. The program plans to launch its rocket in 2027.

As part of the DRACO program, aerospace company Lockheed Martin has partnered with BWX Technologies to develop engine and fuel cell designs.

The heat transfer nuclear engines being developed by these groups will need to meet specific performance and safety standards. They will need to have a base that can work for the duration of the mission and make the necessary steps for a quick trip to Mars.

In fact, the engine should be able to produce a specific impact, while satisfying the high weight requirements of the engine.

Ongoing research

Before engineers can design an engine that meets all these criteria, they need to start with prototypes and simulations. These models help researchers, like those in my group, understand how an engine can handle starting and shutting down. These are processes that require rapid, large changes in temperature and pressure.

A nuclear fuel engine will be different from all existing fission power systems, so engineers will need to develop software that works with this new engine.

My team designs and evaluates nuclear reactors using models. We are modeling these complex reactor systems to see how things like temperature changes can affect the propellant and rocket safety. But simulating these effects can take very expensive computing power.

We are working on developing new computer tools that show how these reactors work while they are starting up and running without using a lot of computing power.

My colleagues and I hope that one day this research can help create models that can control a rocket automatically.