In the magazine Scientia Sinica Technology, Under review, the Chinese Academy of Sciences published a paper reporting the successful testing of the first prototype of a 1.5 MW nuclear rocket engine. The engine unit, whose dimensions were taken from a shipping container, was tested without nuclear fuel, with heat from an external source. The purpose of the tests was to check the heat removal system from the lithium-based reactor. Tests with nuclear fuel are being prepared.

It is clear that to fly to Mars, a rocket must be mounted in Earth orbit or lunar orbit. It will rise into space in pieces, which is also true for a nuclear reactor. At the same time, the issue of safety will be paramount, so that in the event of an accident it does not result in contamination of the earth’s surface with radioactive substances or worse.

The nuclear rocket engine created in China in this version (it is not a fact that the project will be implemented in the current version) will weigh less than eight tons and be compact enough to fit into the standard fairing of standard launch vehicles. The reactor will be deployed in space and equipped with cooling radiators and necessary hardware. In its expanded form, if the article is to be believed, it will be as tall as a 20-story building.

A radiator system made of a tungsten-based alloy will also act as a shield against radiation occurring in the reactor during the decay of nuclear fuel. It is stated that the coolant temperature in the “Rocket” reactor will reach 1276 °C, which is much higher than in conventional reactors. Due to the high temperature, the inert gases helium and xenon will transform from the liquid phase into a gas, which will rotate the turbine of the generator and provide high power in combination with rather compact dimensions of the installation.

The Chinese project is said to be much more compact and seven times more powerful than the rival NASA project. Moreover, Chinese scientists estimate that a journey to Mars with a nuclear-powered rocket will take about three months, while a journey with Elon Musk’s Starship will take seven months. In other words, according to China, dreaming of regular flights to Mars without nuclear-powered rockets is a utopia.

The issue of thrust created by the Chinese nuclear engine has not been clarified. These can be electric motors that accelerate reactive mass particles (neutral gases or water), or motors on fission fragments in which decay products are used as reactive mass. Judging by the content of the news, this is most likely the first case of electric rocket engines, but it is not certain.

It is planned to cool the overheated engine with lithium, which is the most suitable and heat-intensive coolant for the specified conditions. The heat removal system was tested on a prototype with its help. Chinese scientists are cautious in their predictions about creating a working engine. It will take years of experiments and scientific studies. But they hope to achieve this in their mid-30s. Recently, the head of “Roscosmos” Yury Borisov slandered that Russia and China may send a nuclear reactor to the moon for a permanent lunar base in 2033-2035. But that’s another story.