On the Chinese space station, astronauts skillfully use a hot air baking device to prepare fragrant grilled chicken wings. This seemingly ordinary scene of home cooking represents the ultimate test of a sophisticated air purification system involving cutting-edge filtration technologies such as HEPA and ULPA .
The Challenge of Cooking in Space: The Limits of Air Purification in Microgravity
In the microgravity environment of space, cooking fumes and food particles do not settle naturally as they would on Earth, but instead float continuously. These oil droplets, barely visible to the naked eye, are mostly between 0.1 and 0.3 micrometers in diameter—precisely the size range that HEPA and ULPA filters need to precisely capture.
China’s aerospace industry has developed a special “space kitchen” system for this purpose. The hot air baking device in this system incorporates multi-layered filtration modules , capable of instantly processing cooking fumes and suspended particles generated during cooking. This system’s efficiency is astonishing—it filters over 99.97% of 0.3-micron particles, equivalent to medical-grade HEPA filtration standards , while the performance of some key components even approaches ULPA levels.
HEPA and ULPA: The Invisible Guardians of the Space Station
HEPA filters primarily purify the air in most areas of the cabin, capturing larger particles such as dander and fibers, with a filtration efficiency exceeding 99.97%. ULPA filters, on the other hand, are used in areas with precision instruments and certain critical interfaces, achieving a filtration efficiency of up to 99.999% for even smaller particles (0.1-0.2 microns), ensuring the safety of scientific experiments requiring zero tolerance for microparticles.
Markus Fischer, a life support systems engineer at the European Space Agency pointed out: “On the International Space Station, we used a combined filtration system—a pre-filter extends the life of the HEPA filter, and the HEPA filter protects the ULPA. This tiered design significantly reduces system maintenance requirements.”
German Practice: From Urban Air Pollution Control to Trenntech Technological Innovation
Major German cities such as Berlin and Munich are leaders in sustainable urban air pollution control, and their experiences offer important lessons for air quality control in space environments.
German filtration technology innovators, such as Trenntech, have developed a new multi-stage separation filtration system. This system combines mechanical separation with electrostatic adsorption principles, achieving significantly higher removal efficiency for fine particulate matter than traditional methods. It also excels at handling ultrafine oil mist generated during space cooking. “In terms of materials, the latest research shows that nanofiber filter materials based on electrospinning technology are demonstrating their value in the space environment. Compared with traditional glass fiber filter materials, this new material reduces airflow resistance by more than 30% while maintaining the same filtration efficiency, and is more resistant to radiation and temperature fluctuations in the space environment.
From ensuring the purification of cooking fumes in space kitchens to protecting the manufacturing environment of semiconductor chips, from Trenntech’s innovative technologies to Munich’s intelligent monitoring systems, HEPA/ULPA technology has transcended the simple scope of ‘air filtration’ and become a key foundation supporting the development of high-tech industries.”