World's blackest material opens doors for aerospace industry
Vantablack S-VIS sees successful integration on the Kent Ridge 1 microsatellite, obtaining qualification for use in space within five weeks.
Surrey Nanosystems, UK, and Berlin Space Technologies (BST), Germany, are celebrating the successful inaugural use of Vantablack in space, as coating for the baffles – a mechanical system to shield the system from stray light – on the Kent Ridge 1 microsatellite, improving the performance of the star tracker-based positioning control system.
BST opted to use Vantablack S-VIS, a variation of Vantablack that is deposited using a chemical vapour deposition (CVD) process. S-VIS is similarly formed from carbon nanotubes, but each nanotube is shorter and, when chemically bound, forms an open coral-like structure. Ben Jenson, Chief Technology Officer of Surrey Nanosystems, said, ‘At 700nm, Vantablack S-VIS has 99.8% absorption, and 0.2% total hemispherical reflectance (THR). A typical black coating used in space application, such as Aeroglaze Z306, which is used inside the Hubble Space Telescope, has 97% absorption, so a THR of 3% at the same frequency.’
Although it features a lower light absorption rate compared with original Vantablack – 99.8% compared with 99.965% – the CVD process widens the number of potential applications, and allows coating of larger shapes and structures.
Surrey Nanosystems joined the Kent Ridge 1 project shortly before the equipment design was to be locked down, and completed the baffle coating within five weeks, including provision of specifications and detailed technical discussions. ‘It’s almost unheard of, getting something into space like that,’ said Jensen. ‘Normally, to qualify a material for space can take many years – typically, if we were working on a flight cavity for a satellite, it might be a five-year project before it gets flown – but, because of the pre-qualification work we had done, as well as pre-qualification from BST, we managed to qualify the material in record time during this five-week process.
‘For something to be done based on the qualification work performed prior to working with BST, and their own qualification work, and have it perform so successfully… it’s never been done quite like this before.’
The use of Vantablack S-VIS is expected to proliferate, with Jensen citing ‘light suppressors in high-value camera lenses to combat lens flare, cinematography projectors, passive and active infrared sensors,’ as well as a number of undisclosed space missions in the near future.
Although the Kent Ridge 1 microsatellite launched in December 2015, Surrey Nanosystems decided against publicising the use of Vantablack S-VIS until late May 2016. Jensen said, ‘This is mainly because when you launch something into space, you want to make sure it’s working 100% before you start shouting about it. So for the first few months, the satellite operators were confirming everything was working properly and performing in the manner intended. Once we knew that, we were given the go-ahead for announcement.
‘Some people will announce straight away, but we had a small part in a new development satellite. We wanted to make sure the material was working effectively and delivering on expected performance, and the only way to do that is to have it up in space. You can do all of the tests you want on the ground, but the real test is having it in space, as it’s such a difficult environment. For us, it was better to wait than announce it immediately and risk finding out there was something wrong a few weeks later.’
For more information on Vantablack, see Natalie Daniels’ 60 Seconds on… in Materials World, June 2016.