Australia’s contribution to the global space industry has grown with CSIRO developing a mapping device for the International Space Station.
CSIRO Senior Mechanical Engineer Lauren Hanson was design lead in a team that developed technology to support 3D imaging, mapping and navigation of the interior of the 26-year-old International Space Station (ISS).
The team within Australia’s national science agency, CSIRO, had their multi-resolution scanner (MRS) boosted into orbit last year. It has completed its first mission on board the ISS’s autonomous flying Astrobee robots, with future experiments planned throughout 2025.
The CSIRO/Boeing project, in collaboration with NASA and the ISS National Laboratory, combined and adapted existing CSIRO sensing technologies used in mining and spatial mapping. This included two stereo cameras and three time-of-flight sensors and inertial measurement units. The task was to make it all resilient and safe enough for use in space.
Several different communication protocols are used on the payload, with USB3 being one of them. Protocols such as USB3 have an electromagnetic interference (EMI) signature that needs to be mitigated through proper shielding of cables, as EMI could interfere with other experiments on board the ISS.
“Part of the challenge in accommodating cable shielding is that the payload volume and weight budget are so small,” Hanson said. “Adding shielding also increased the bend radius of cables, and careful cable layout and support was vital to maintain integrity through vibration testing and launch.”
NASA has carefully defined EMI safety standards. So, the challenge was to find ways to securely wrap the cables with appropriate shielding.
“It took a whole lot of testing. And that means measuring everything from how much EMI was leaking through to vibration testing to be certain our connectors were adequately secured.”
It was a scramble, but the MRS module was completed and delivered early in 2024. By August, ISS astronauts had fitted it to the payload bays of one of their AstroBee robots.
“As the mechanical engineer, I can say all the sensor’s power is on. Everything seems connected and functional. So I’m happy.”
But Hanson added that important lessons were learned.
Designing the complex payload, which includes three different sensing modalities and onboard computers, to satisfy both functional and NASA safety requirements, was exciting and challenging.
“There were some required parts that we needed, such as mating connectors, specific magnets and threaded inserts,” she explains. “They’re readily available in the US, but trying to get them in Australia is costly. It’s time-consuming. So, if you suddenly discover you don’t quite have enough, it adds a substantial delay.
“That definitely hit us once or twice.”
On the one page
The other problem was expected, but more difficult than anticipated: NASA speaks a different language.
“We’ve got an in-house workshop, which is fabulous,” Hanson said. “But while most of the dimensions for the payload and onboard sensors are metric, some of the interface dimensions to mate with the Astrobee must be imperial. So, I was sending parts and engineering drawings to our manufacturing team, specifying both imperial and metric measurements and tolerances on the same part.
“That definitely produced a few moments of stress.”
The solution was to test to ensure the right tolerances and standards were being met.
Then there’s the matter of space and weight. One NASA requirement was to place a fine stainless steel mesh across the whole payload package.
“That added quite a substantial amount of mass for your small payload mass budget,” Hanson explained.
It’s not needed on Earth but it’s a vital fire containment measure and finger-protector in space.
“The computer gets to perhaps 80°C. The safety requirements are so much more stringent.”
NASA made its ground-based Astrobees available for testing the payload at the Ames Research Centre. This was important as the MRS was the first payload permitted to occupy two of its payload slots for the necessary power and room.
“This was a first for us and for NASA. So, we’re tackling these challenges together, trying to make sure we can effectively and reliably mount this hardware using latches and connectors that were generally not intended to be used this way.”
NASA’s testing facilities were extensive and combined.
“In Australia, it’s simply not as easy,” Hanson added. “The facilities can be quite dispersed and not necessarily close to where you’re building the hardware. But testing is absolutely crucial.”
And every unexpected problem demanded unscheduled testing.
“Because of our relationship with Boeing, we got access to the world-class EMI and vibration testing facilities we needed. Without it, our payload almost certainly wouldn’t be in space today.”
And while testing facilities were scarce, so was the skill and understanding needed to exploit them properly.
“For me, this experience has reinforced the critical role of early and thorough testing, and the need for greater access to world-class facilities to support the growth of the Australian space industry. The ability to test makes a huge difference, and I’m looking forward to making it a key part of my next challenge.”
