Algorithm creates new, lighter design for space telescope

Could today’s top technology improve on a 15-year-old engineering masterpiece? Using the latest design methods, TNO is remaking the Ozone Monitoring Instrument’s (OMI) telescope. The original OMI, which was launched in 2004, is still making measurements of the Earth’s atmosphere. The upgraded telescope is lighter, cheaper and at least as effective as its predecessor: “We deliver world-class products.”

Floris van Kempen did his PhD research on optimization techniques in Delft: “Using these techniques, you can get computers to design equipment. All people have to do is set the preconditions. The calculations are performed by computers or, to be more accurate, algorithms that use topology optimization. This system then delivers a design. So it is actually a form of artificial intelligence.” These designs are often quite astonishing: “Over time, people have developed fixed habits of thought, but computers have no such restrictions.”

3D printing in metal

“There was a good reason for the limitations in our thinking habits”, says van Kempen. “Coming up with an innovative design is one thing, but implementing it is quite another. Here, the coming of age  of 3D printing in metal has opened up a world of possibilities.”

"OMI is a space-based instrument that measures - among others - nitrogen levels in the Earth's atmosphere"

It’s time to put this combination of technologies to work. Together with other knowledge institutions and the international business community, TNO has fabricated a remake of OMI’s telescope. This instrument’s capabilities include using optical spectroscopy to make space-based measurements, both of the ozone layer and of nitrogen levels in the Earth's atmosphere. Floris van Kempen explains that “OMI has to make extremely accurate measurements; yet, in space, one side of the instrument is exposed to the burning heat of the sun while the other side is freezing cold.”

Seventy percent lighter

This telescope – with the associated optical system – is the most vulnerable part of OMI. van Kempen says that “Not only is the computer-generated design seventy percent lighter, sturdy enough to survive the launch, and easy to produce and test, it is also cheaper to use. We confirmed this by using a comprehensive battery of tests here on Earth.”

“The algorithm created design elements with dual functionality, such as partitions that also serve as sun shields"

The shape of the new design was a little surprising: “It wasn’t the usual boxy design that people tend to produce. It’s more like a frog or a dog, with rounded organic profiles. “The algorithm created design elements with dual functionality, such as partitions that also serve as sun shields, but made them slightly thicker.” In addition to carrying some of the mechanical load generated during launch, they also help to keep the temperature stable while measurements are being made.”

“The potential applications of this technology go way beyond Earth observation from space"

On display at the Precision Fair

TNO developed the telescope in a project for ESA, in collaboration with OHB, Materialise, SRON, IABG and Fraunhofer IFAM. TNO is cooperating with other knowledge institutions and the business community to further explore the potential of this innovative approach. The new telescope will be on display at the Precision Fair in Veldhoven, on 13 and 14 November.