Particle physics experiments

China’s space station will have flames in controlled experiments

02:34

There may soon be small fires aboard the China Space Station (CSS) – but don’t worry, the fires will be safe, orchestrated and closely monitored. The study of these flames would contribute to scientific studies of combustion.

Liu Yucheng, an associate professor at the Center for Combustion Energy at Tsinghua University, showed CGTN in a ground-based experiment how the first flame would ignite similarly in the CSS Combustion Science Rack (the rack is partly developed by his team), hopefully within this year.

Liu said the flames in space would be different from those he creates on Earth. “The flame in space will seem larger, due to the lack of buoyancy.”

And the flames would be completely safe. “What we’re going to create are very small flames in space. That’s the gist of it and the whole combustion chamber design is capable of withstanding three times the pressure needed for typical combustion experiments that would be conducted in space.”

The first experiment of its kind on China’s Space Station would look closely at how space flames ignite, burn and extinguish to answer some fundamental questions on the ground. Liu said combustion is one of the perfect problems for space experiments where unwanted elements on the ground can be removed.

He also said that the scientific support of burning CSS is unique in that it provides scientists with research material. “In the Chinese space station, the Combustion Science Rack actually provides the technique that basically helps scientists visualize flux using particles. We have high-speed cameras to do what we call temperature reconstruction soot. And we are able to reconstruct the 3D structure of a flame in space.”

“These are very special features that the International Space Station (ISS) didn’t have,” he said.

03:27

Flagship device on CSS

“It will be the biggest experiment on the Chinese Space Station,” astrophysicist Zhang Shuangnan told CGTN, showing a key part of the High Energy Cosmic Ray Detector, or HERD. And HERD, when completed, would be “the greatest experiment on CSS”.

Zhang, a professor at the Chinese Academy of Sciences’ Institute of High-Energy Physics, said the HERD would be such a landmark that “if you have a telescope that looks up, it will be the only thing you you will be able to identify. It will be a point of reference”.

Size aside, many have considered HERD a “flagship” experiment because when it works, it’s poised to provide unprecedented understanding of dark matter and the universe. And understanding would come from unprecedented data that HERD would receive.

“The goal of the experiment is that we will detect the most active energy particles in space with the highest precision. That is the goal. That is why we are designing the experiment to have this large dimension to to have that weight, and to be able to receive particles from all directions,” Zhang said.

HERD is said to weigh around 4 tons, and for years it is also a heavy project that has attracted the best minds from China and around the world. The team working on HERD includes more than 200 scientists, more than half of whom are European. The other half comes mainly from the Chinese mainland, as well as the Hong Kong Special Administrative Region and the Taiwan region.

“Each institute brings its best technology for us to work together. We can build the best experiment in the world. We hope that when it is delivered to the Chinese Space Station, it will be the main experiment in this field for at least 10 years and we hope for even more,” Zhang said.

He said they hoped HERD, a project started 15 years ago, could come to CSS within the next five years.

HERD is estimated to weigh around four tons.  /Institute of High Energy Physics of the Chinese Academy of Sciences

HERD is estimated to weigh around four tons. /Institute of High Energy Physics of the Chinese Academy of Sciences

HERD is estimated to weigh around four tons. /Institute of High Energy Physics of the Chinese Academy of Sciences

Black hole experiment

Zhang’s team has another international cooperation experience that could be embarked earlier.

This is a larger study of gamma-ray bursts called POLAR 2, which will help understand black holes. It follows the POLAR project which was carried out on the Chinese space laboratory Tiangong-2 in 2016.

“The Chinese space station has many unique capabilities. In particular, when the ISS comes to the end of its lifespan, it will be very difficult to accommodate new experiments on the international space station, at least it is very uncertain. So China’s space station might be the only opportunity for international scientists if they’re going to use this kind of lab for the experiment,” Zhang said.

As for what China’s space station would mean for discoveries, Zhang is optimistic. “It’s not a question of whether we’re going to set world records, but exactly what the records are,” he said.

“We don’t know because it’s a completely unknown frontier. In any scientific research, when you’re at the cutting edge, you don’t know what’s beyond. You can only do your best, build the best instrument and wait for what nature and the universe tell us.”