Casting the Mirror for the World’s Largest Telescope

via IEEE Spectrum

Building a mirror for any giant telescope is no simple feat. The sheer size of the glass, the nanometer precision of its curves, its carefully calculated optics, and the adaptive software required to run it make this a task of herculean proportions. But the recent castings of the 15-metric ton, off-axis mirrors for the Giant Magellan Telescope (GMT) forced engineers to push the design and manufacturing process beyond all previous limits.

Building the GMT is not a task of years, but of decades. The Giant Magellan Telescope Organization (GMTO) and a team at the University of Arizona’s Richard F. Caris Mirror Laboratory cast the first of seven mirrors back in 2005; they expect to complete construction of the telescope in 2025. Once complete, it’s expected to be the largest telescope in the world. The seven 8.4-meter-wide mirrors will combine to serve as a 24.5-meter mirror telescope with 10 times the resolution of the Hubble Space Telescope. This will allow astronomers to gaze back in time to, they hope, the materialization of galaxies.

Each mirror costs US $20 million dollars and takes more than two years to build. Every stage of the manufacturing process calls for careful thought and meticulous planning. To begin, more than 17,000 kilograms of special glass are ordered and inspected for flaws. Next, a crew must build a 15-metric ton ceramic structure to serve as a mold for the glass, which they carefully place one chunk at a time. The glass is slowly melted and continuously spun in a furnace to create a parabolic shape, then cooled by fractions of degrees over the course of three months. And that’s only the beginning.

Read more!


As 2022 starts, let’s take some time to share our goals for CircuitPython in 2022. Just like past years (full summary 2019, 2020, and 2021), we’d like everyone in the CircuitPython community to contribute by posting their thoughts to some public place on the Internet. Here are a few ways to post: a video on YouTub, a post on the CircuitPython forum, a blog post on your site, a series of Tweets, a Gist on GitHub. We want to hear from you. When you post, please add #CircuitPython2022 and email circuitpython2022@adafruit.com to let us know about your post so we can blog it up here.

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 32,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


Maker Business — Pololu’s account of the chip shortage

Wearables — Stay frosty

Electronics — High voltage logic

Python for Microcontrollers — Python on Microcontrollers Newsletter: New Releases of MicroPython and CircuitPython and more! #Python #CircuitPython @micropython @ThePSF

Adafruit IoT Monthly — 2021 in Recap!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — JP’s Product Pick of the Week — 4pm Eastern TODAY! 1/18/22 @adafruit @johnedgarpark #adafruit #newproductpick

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



No Comments

No comments yet.

Sorry, the comment form is closed at this time.