Powdered bones are keeping Solar Orbiter cool thanks to an Irish startup #Breaking112
After ESA put out an invitation for solutions, it was approached by Irish biotechnology company ENBIO. It had developed a technique to apply synthetic bone coatings to orthopedic and dental implants, to make them more easily accepted by a patient’s body. Because the technique reduced weight and prevented issues like flaking, ENBIO thought it could be useful for the titanium surfaces of Solar Orbiter.
But the synthetic bone was light-colored and testing showed that it would darken after prolonged exposure to sunlight, changing the amount of heat it absorbed and reflected. A black coating meant its properties would be stable for the whole mission, absorbing the sun’s energy as heat and then dumping that into space.
“I tried to color the bone powder to make it black, but it didn’t work too well,” recalled John O’Donoghue, the founder of ENBIO.
Instead, he started looking for a naturally black bone powder. “I remembered reading as a kid that in cave art, people used charcoal and, in some cases, [burnt] animal bones, because the end of it would be like a crayon and they could draw on walls,” he said.
After O’Donoghue sourced some burnt animal bone powder, ESA found it was ideal for the solar mission. In addition to being black, there’s nothing combustible left in the material — so when it’s heated up it, doesn’t release any gases that could damage the spacecraft, explained Garcia Marirrodriga.
Aiming for space
O’Donoghue’s interest in coating technology began while studying biomedical engineering at Trinity College in Dublin. He founded ENBIO in 2006 and in 2015, the company opened a €1.5 million ($1.8 million) industrial coating facility in Clonmel, about 100 miles southwest of Dublin. Solar Orbiter has earned the company several million euros, according to O’Donoghue, and ESA has deployed SolarBlack on other missions.
O’Donoghue said the coatings and the coating process can find applications in the automotive, metal, heating and energy industries, among others, but the current focus lies beyond this planet. “We aim for the space sector because we felt if we go to the top of the pyramid and [do well there], the rest of the industry will be more accepting of it,” he said.
Although its main mission won’t start until November, last July Solar Orbiter sent back the closest images of the sun ever taken.