Astronauts face a variety of risks during spaceflight, including microgravity, which can reduce bone density, and radiation exposure, which is a carcinogen, but these are chronic effects.
The biggest risk for astronauts is fire, as escape would be difficult on a long mission. Mars Or somewhere beyond low Earth orbit. Scientists are studying the behavior of fires on board spacecraft to protect astronauts.
Scientists at the University of Bremen’s Center for Applied Space Technology and Microgravity (ZARM) are investigating the risk of fire on board spacecraft.
They wrote in the Proceedings of the Combustion Research Institute:Effect of oxygen concentration, pressure and counterflow velocity on flame spread along a thin PMMA sheet.“The lead author is Hans-Christoph Riis.”
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“A fire on board a spacecraft is one of the most dangerous scenarios during a space mission,” said Dr Florian Meyer, head of the Combustion Technology Research Group at ZARM.
“There are few options for moving to safety or escaping the spacecraft, so understanding how fires behave under these unique circumstances is crucial.”
Since 2016, ZARM has been studying how fires behave and spread in a microgravity environment like the ISS.
These conditions include Earth-like oxygen levels, forced air circulation, and Earth-like air pressure. NASA Conducting Similar ExperimentsAnd we now know that fire behaves differently in microgravity than it does on Earth.
Fires start out small and take a long time to spread, which is an advantage for the fire because it doesn’t get noticed right away.
Also, because fires burn hotter in microgravity, materials that wouldn’t burn in a normal Earth environment could burn inside the spacecraft, creating toxic chemicals in the air aboard the craft.
Spacecraft for Mars missions will have a different environment than the ISS: the lower ambient air pressure has two advantages: it makes the spacecraft lighter and allows astronauts to prepare quickly for external missions.
But the lower ambient air pressure creates another significant change to the spacecraft’s environment: the oxygen content must be increased to meet the astronauts’ respiratory needs.
In the latest tests, the team from ZARM carried out fire tests under these revised conditions.
PMMA stands for Polymethyl Methacrylate, commonly referred to as acrylic. It is a material often used in place of glass because it is light and shatter-resistant. It is not used on the ISS, but is being developed for use on future spacecraft. The windows on the Orion spacecraft use acrylic fused with other materials, and future spacecraft may use similar materials.
In their experiments, the researchers set a piece of acrylic glass foil on fire and varied three environmental factors: the surrounding pressure, oxygen content, and flow rate.
They are Bremen Drop Tower To simulate microgravity.
Experiments have shown that the lower the surrounding pressure, the weaker the fire, but the higher the oxygen content, the stronger its effect. The International Space Station has oxygen levels of 21%, the same as on Earth.
In future spacecraft, where the ambient pressure is lower, oxygen levels will rise to 35%, meaning astronauts will be at a much increased risk of catching fire: Research has shown that fires could spread three times faster than under Earth conditions.
“Our findings highlight important factors that need to be taken into account when developing fire safety protocols for spaceflight missions,” said Dr Florian Meyer from ZARM’s Combustion Technology Research Group.
We all know that increased air currents make fires spread faster, that’s why we blow on a small flame to make it bigger. Increased air currents in an oxygen rich atmosphere create dangerous situations for astronauts, because increased air currents provide more oxygen and promote combustion.
“Our findings highlight important factors that need to be taken into account when developing fire safety protocols for spaceflight missions,” said Dr Florian Meyer.
“Understanding how fires spread under different atmospheric conditions can help reduce fire risks and improve crew safety.”
This article is The Universe Today. read Original Article.
