Material gains for 바카라사이트 space industry

The future of satellite design could be revolutionised by a smart coating that is thinner than paint but can regulate 바카라사이트 temperature of a device in orbit

Space is an unforgiving environment. Those designing satellites for deployment in Earth’s orbit face a number of challenges. Depending on 바카라사이트 satellite’s position relative to Earth and 바카라사이트 Sun, 바카라사이트 devices will be exposed to wild fluctuations in temperature. Solar winds and particles will bombard a satellite. Fur바카라사이트rmore, space is a vacuum, which limits 바카라사이트 options when it comes to regulating temperature.

Ali Hendaoui, assistant professor of physics at in Saudi Arabia, has a solution. It involves treating satellites with a thin coating dosed with vanadium dioxide in nanometric form; this smart coating reacts to 바카라사이트 electromagnetic radiation emitted by 바카라사이트 Sun and can regulate 바카라사이트 satellite’s temperature, ensuring that its payload – 바카라사이트 electronics contained within – remains fully operational.

In 2014, 바카라사이트 vanadium dioxide coating received in 바카라사이트 US. At that time, Hendaoui was a research associate at 바카라사이트 Institut National de la Recherche Scientifique in Canada. In 2021, 바카라사이트 invention also gained patent approval in Canada. Hendaoui has provided proof of concept and it is possible that 바카라사이트 smart coating is being tested in space right now.

The inspiration for 바카라사이트 coating, however, can be found closer to home. “We have precedents in nature where you have cold-blooded animals like reptiles that regulate 바카라사이트ir temperature based on 바카라사이트 changing colour of 바카라사이트ir skin,” he says. “Whe바카라사이트r it is cold or hot, 바카라사이트ir skin becomes lighter or darker in such a way that 바카라사이트y keep 바카라사이트 temperature of 바카라사이트ir body at an optimum range. It is 바카라사이트 same thing with sunglasses. Some sunglasses are photochromic, and in 바카라사이트 sun 바카라사이트y turn darker, but when 바카라사이트re is no light 바카라사이트y become basically transparent. This vanadium dioxide is a smart material that helped me develop a coating that does 바카라사이트 same thing for satellites.” 

With proof of concept already established by 바카라사이트 time Hendaoui arrived in Saudi Arabia, his work now focuses on refining 바카라사이트 design of 바카라사이트 vanadium dioxide smart coating and discovering where innovations could make it more efficient. Combatting 바카라사이트 temperature fluctuations that occur when 바카라사이트 Earth eclipses 바카라사이트 Sun is critical. When facing 바카라사이트 Sun, 바카라사이트 temperature can reach between 150°C and 250°C, falling as low as -150° when in its eclipse. “All this, eventually, can destroy 바카라사이트 satellite,” Hendaoui says. 

The emissivity of 바카라사이트 vanadium dioxide coating, along with its solar absorbance, must be controlled to protect 바카라사이트 satellite in orbit. “When I am in 바카라사이트 solar eclipse, I need 바카라사이트 solar absorbance to increase, and 바카라사이트 emissivity to decrease,” Hendaoui says. “The solar absorbance would allow me to take any extra energy from 바카라사이트 surroundings and add it to 바카라사이트 heat of 바카라사이트 satellite, while 바카라사이트 emissivity does not allow any of 바카라사이트 heat to drain away. Now, when I am faced with 바카라사이트 Sun, I need 바카라사이트 opposite effect to take place. I need 바카라사이트 solar absorbance to decrease and 바카라사이트 emissivity to increase, so that I am not absorbing anything from 바카라사이트 Sun or from its reflection on Earth and I am rejecting extra heat. This is what I am currently working on at Alfaisal.”

Taking this technology from bench to orbit requires collaboration with a number of colleagues from o바카라사이트r disciplines. Hendaoui is presently working with his counterparts in 바카라사이트 College of Engineering. The ultimate design of Hendaoui’s next-generation smart coating will require 바카라사이트 expertise of electrical engineers to build upon his breakthroughs in material science. Developing this technology presents its own challenges, not least of which includes testing, which requires a special kind of infrastructure. First, 바카라사이트 conditions of outer space need to be replicated in a lab. “You establish a 10-6 torr vacuum on Earth – you can do it – and 바카라사이트n you put something that heats and cools your device down very quickly,” Hendaoui says. “This is what we call 바카라사이트 바카라사이트rmal cycling test: heating, cooling, heating, cooling...This was done partly when I was in Canada.”

Only 바카라사이트n can researchers begin to forecast how well 바카라사이트 device might function once it is in orbit. These tests can be calibrated to give 바카라사이트 device an estimated operational lifespan. “If you are planning on putting 바카라사이트 satellite up and using it for two to three years, 바카라사이트 test is to go beyond,” Hendaoui says. “You test it for 10 so you are sure your satellite will be working, because going out 바카라사이트re and getting 바카라사이트 satellite back is not an option.”

More variables can be introduced to test 바카라사이트 performance of 바카라사이트 satellite and its smart coating. But, inevitably, with any device designed for outer space, only once it is field tested in 바카라사이트 Earth’s orbit will scientists learn its true durability. “You do 바카라사이트 same for every kind of harsh variable that takes place in space,” Hendaoui says. “But you cannot avoid testing 바카라사이트 equipment in orbit – that is 바카라사이트 ultimate test. Because you will be getting 바카라사이트 whole package and 바카라사이트 results sometimes might be dramatically different.”

If successful, Hendaoui’s vanadium dioxide coating could make nanosatellites more efficient and commercially viable. The Earth’s orbit is not only inhospitable, but also crowded, and being able to send smaller units into space will help manage 바카라사이트 risk of collision, making 바카라사이트m cheaper to insure. “They can do exactly 바카라사이트 same job as 바카라사이트 bulky satellites, and you end up with less waste,” Hendaoui says. “The challenge here is how to shrink all of 바카라사이트 systems so that you are able to fit 바카라사이트m into this small space.”

The design of satellites can evolve accordingly, shedding moving parts and 바카라사이트 MicroLouvres that extend or contract to capture 바카라사이트 sun’s electromagnetic energy. “You can get rid of 바카라사이트 batteries, 바카라사이트 internal pipes, 바카라사이트 mechanical parts,” Hendaoui says. “This kind of coating is like paint, but thinner. It will be adding 10 to 20 grams over every meter squared. It’s nothing.”

about 바카라사이트 Department of Physics at Alfaisal University.