Precision optics made in New Zealand are at the heart of a new astronomical instrument about to start operating in the Canary Islands.
Lenses from Lower Hutt are part of the wide-field multi-object spectroscopy project (WEAVE) which will probe discoveries from both ground-based and space-based telescopes.
It is expected to the produce the first astronomical image - known by astronomers as "first light" in mid-2018, and to operate through to at least 2023.
And the New Zealanders helping to unlock the secrets of the universe are at KiwiStar Optics, which makes multi million dollar lenses for some of the world's largest telescopes for observatories all over the world, from South Africa, Australia, Chile, Hawaii and India.
KiwiStar manager Sandra Ramsay said the company built the reputation and capability to beat off tough competition from lens manufacturers in the United States.
"The capability is so strong here that the client is prepared for the glass to be sent from Germany to New Zealand go back to the States, up and down a couple of times," she said.
A large lens can take between 18-20 months to build, but there can be up to 5 years of discussion narrowing down technical details and the science of what's required.
"Generally the glass is sourced from Germany, it comes here, we work on it, polish it and grind it, but sometimes it has to go back to the States to be coated, then it has to come back here to be tested, then go back to the States, so there's a lot of travel time on a lens," she said.
The lenses, which can be up to 1.1 metres in diameter, are tested before they are sent away and packed in large crate, which is filmed for the client.
Optical engineer Dijana Bogunovic said while lenses were an established technology, KiwiStar was also developing spectographs to analyse the light from the stars.
Spectographs are instruments that take the light reaching the telescope from the star and then spread it into the spectrum and then analyse that. Astronomers can use the data to determine the speed the star is moving, what it's made of, how fast it is spinning, and temperature, she said.
This technique works by capturing the light from the galaxy and spreading it out into a spectrum according to its wavelengths. The pattern of lines shows up the different elements in the stars that make up the galaxy. And the farther away the galaxy, the more the expansion of the universe shifts these lines to appear at longer wavelengths and lower frequencies than they would appear in a laboratory here on Earth.
So the size of this so-called "redshift" gives the distance to the galaxy.
Early surveys of galaxy positions painstakingly measured such spectra one galaxy at a time, pointing the telescope at each galaxy in turn. Modern surveys by instruments such as the William Herschel Telescope at La Palma in the Canary Islands can now record up to a few thousand galaxy spectra in a single exposure.
KiwiStar has manufactured six lenses for its WEAVE multi-object survey spectrograph - including one of the world's biggest at 1.1m.
Ms Ramsay likened the work to that of a Swiss watchmaker - craftsmanship backed by a lot of science.
"I can't see robots can come in and take away our work, because it's the human eye and the human touch that is required," she said.
The small team of 12 staff - which they hope to increase to 15 next year - comprises mostly engineers who have experience working with glass.
Currently the team is working on two large multi-million dollar contracts and four smaller ones.
Ms Ramsay says there's a fascination in astronomy to see the next big thing, which makes it an exciting area to work in.