Russia planning to develop a Nuclear Spaceship to visit Jupiter

What do we know so far about the Zeus Program? 

The public first heard about the Zeus program back in May 2021. The details were announced by Alexander Bloshenko, the Executive Director for Long-Term Programs and Science at Roscosmos. While giving a presentation at the new knowledge forum held in Moscow, Alexander went into some juicy details about their plan to develop nuclear propulsion rockets and much more. 

According to Russian reporting agency TASS, Roscosmos has already signed a contract with a private Russian engineering company Arsenal Design Bureau to start working on the proposed nuclear-powered space tug. It is also known as TEM or Transport and Energy Module. The contract is estimated at 4.17 billion rubles, which is about 57.08 million US dollars 

While talking at the new knowledge forum held in Moscow, Alexander laid out Roscosmos plans for a mission to Jupiter that would be using the nuclear-powered spacecraft. 

A brief history of Nuclear Propulsion

As early as 1944, scientists like Stanisław Ulam and Frederic de Hoffmann had started to work on ideas to use nuclear energy to launch vehicles into space. In 1946, the United States Army Air Force saw the benefit of using nuclear propulsion to power their fighter aircraft. To this end, the Aircraft Nuclear Propulsion Program or NAP for short and subsequently the Nuclear Energy for the Propulsion of Aircraft Program or NEPA were started to develop a nuclear-powered rocket engine. 

Reports from the programs later identified that it was, in fact, possible to create a reactor engine by using a molecule of low molecular weight. But due to the technological limitations of the time, it was impossible to fabricate and operate such an engine back then.

In 1961, the Atomic Commission and NASA started the nuclear engine for rocket vehicle application program, NERVA for short. This program designed and developed 20 reactors to be used in rockets. It was later disbanded in 1973 due to budget cuts

It wasn’t until 2018 when NASA again got the funding of about $125 million to start developing a modern nuclear propulsion rocket. With advancements in material engineering, this time, it looks more promising. 

Russia’s history of experimenting with nuclear rocket propulsions is as old as the US programs. Like everything with Roscosmos, their plans to use nuclear energy in space can be traced back to the soviet era. The USSR’s space program launched almost 33 military reconnaissance satellites that were powered with nuclear reactors into orbit from 1969 to 1988. 

These were thermoelectric nuclear power sources that would provide power to the equipment onboard the satellites. USSR was also developing a prototype of nuclear thermal rockets at the same time as NASA was working on their NERVA program. But the USSR project was closed in 1986.

How Nuclear Propulsion Works 

There are two main types of ways nuclear power can be used for propulsions. Nuclear Thermal Rockets or NTR and Nuclear Electric Rockets.

Nuclear Thermal Rocket 

Instead of using the chemical energy of propellants to power a rocket, a Nuclear Thermal Rocket uses nuclear reaction from nuclear fission to provide the energy. A nuclear thermal rocket uses a working fluid like Hydrogen. The Hydrogen is heated using the nuclear reactor on board the rocket and then is forced to expand through a rocket nozzle to create thrust. This has the same effect as a chemical rocket, and this thrust allows the rocket to roar into the air. 

A nuclear reactor on a Nuclear Thermal rocket work the same way as a nuclear reactor in a power plant. First, heat energy is generated from the fission reaction. Then the propellant, liquid Hydrogen, is pumped through the reactor core. This heats up the Hydrogen. This heated Hydrogen is then expanded and accelerated out from the thrust nozzle of the rocket. This creates the thrust for the rocket. 

Nuclear Electric

But this isn’t the only way nuclear energy can be used to generate thrust. Another way to use nuclear energy for propulsion is by combining a nuclear reactor with an electric rocket engine. The electronic propulsions system uses the heat generated by a nuclear reactor to heat up and accelerate ionized gas. This ionized gas is used as a high-speed ejecting mass to generate thrust for the rocket. These are also known as ion or plasma engines. 

This is the route Roscosmsos is taking with their Transport Energy Module program. According to Arsenal Design Bureau, between 2016 and 2018, they had conducted several studies and made early designs of such a spacecraft. The mockup prototypes include a Truss carrier section and a Propulsion Unit Module made for future spacecraft.