Coating the Extremely Large Telescope mirrors with silver | ELT Updates

ESO’s Extremely Large Telescope (ELT) will have a 39-m wide primary mirror, comprised of 798 hexagonal segments working together with nanometric accuracy. The segments are coated with a thin layer of silver to reflect the light from the cosmos. But how does the coating process work? In this video we take you on a behind-the-scenes tour of the ELT’s Technical Facility in Chile where this process takes place.

Credits:
ESO
Directed by: Angelos Tsaousis and Martin Wallner.
Editing: Angelos Tsaousis.
Written by: Barbara Ferreira.
Narration: Graeme Mackenzie/voicearchive
Music: Jon Kennedy – Inner Resting, Andrea Michele Vincenti – New Visions.
Web and technical support: Gurvan Bazin and Raquel Yumi Shida
Footage and photos: ESO / Luis Calçada, Angelos Tsaousis, Jose Porte,
Max Nadjar, Boris Häußler, Herbert Zodet, Juan Carlos González Herrera,ACe/Cimolai.

[EmilianoGirina]

The level of technology and engineering behind this telescope is amazing. I can't wait to see how much, and what kind of science it can produce.

[andrewlabat]

Just incredibly innovative. The painstaking dedicated to producing these perfect segments. All the hats off to these ladies and gentlemen.. 🎩

[RuslanKashyrtsev]

Amazing as everything about the ELT! The giant relying on the nanoscale precision - a great example of how everything work in the Universe! I wish patience to coating engineers team - truly arduous task is ahead!

[mariadaluzmoutinho]

Incrível a minúcia e cuidado...o engenho e arte para ver o reflexo mágico, a prata para moldar de forma nítida e mais brilhante que nunca e vamos sorrir! Que história épica ...mais uma etapa de algo maravilhoso e extraordinário do ELT!!

[Nivola]

I used to work in a microelectronics wafer fab, my job included the process of coating the wafers with thin layers of alloys of Al/Si that will provide the electrical connections. I’m very surprised at the little attention paid in the video to the substrate cleaning process, because I remember the trouble caused by any trace of contaminants, especially organic compounds, which were thoroughly removed with acids baths followed by an extensive rinsing and drying process. I guess you used a sputtering type of deposition, I’m really curious about who built your coating tool.

[bazpearce]

Looking forward to see what this beastie can do.

[Erik-rphi]

Close to LA, ca. is the Mojave Desert where I ride my dirt bike. Can get blowing there with dust. I hope that mountain in Chile does not have the same problem with dust.

[sanjaygatne]

केव्हा पहिले छायाचित्र बघायला मिळेल असे झाले आहे. खुप खुप शुभेच्छा. दुर्बीण लवकर तयार व्हावी.

[ReenaRaut-slrr]

Aspiring to join you in coming years 🙏

[bba]

My 28" mirror needs recoating. It would be good to know someone working the nightshift there, I might be able to get it done for a carton.

[danbaker]

When imaging, are all segments adjusted in real-time? Is there a web pointer for details how the surface shape control system works?

[ptonpc]

This is what happens when humans work together for the betterment of the world.

[ImieNazwiskoOK]

With the amount of mirrors this telescope will need, I think it can be safely considered a literal factory for mass production(and not some manufacturing site for a one off very specific thing). Out of curiosity what is the goal(it seems to currently still be in development so it will probably change) for time needed to make a single mirror?

[saffieification]

will it be another step in our understanding exciting times

[nickm]

How in the name of George Dubya did they not name this thing the BFT? Totally missed out on a great marketing op.

[chrismayer]

When it is time to recoat the mirrors, do they all have to be coated at the same time or can the telescope be operated with a combination of new and old segments?

[michaelanderson]

3.14 km (Pie) diameter space telescope ????

[cabanford]

Wishing we did more of this and less self-centered, short-term, egotistical greed.

[a-fl-man]

there are a lot of smart people out there.