May 2021 Issue
Feature Articles
Will Satellites Cripple Ground-Based Astronomy?
Some worry that the growth of space technology—which originally sprang from humanity’s fascination with the stars—now threatens access to the clear skies vital for research with a new generation of Earth-based telescopes.
by Jeff HechtDepartments and Columns
Harnessing Attosecond Quantum Technologies
Exploring the quantum physics underlying high-harmonic light sources and the exquisite control it provides.
Also in this Issue
30, 20, and 10 Years Ago in OPN
Lithography; atom laser; Arthur L. Schawlow.
Webinar series: From Ph.D. to CEO / “We Are OSA” podcast and blog / New conference video interface / Virtual OFC lineup / 5G webinars / Luminar podcast / OSA Fellow stories / Patricia Bath and Kuo-Nan Liou remembered / Optics advocacy / Chang-Hasnain visits Zhejiang University / Thank you, editors and volunteers

![Manual probe system with needles for test of semiconductor on silicon wafer. [A. Morozov / Getty]](https://opnmedia.blob.core.windows.net/$web/opn/media/images/articles/2025/1125/departments/202511-cover-web.jpg?ext=.jpg)
![Researcher Clara Saraceno in the lab. [Image by Carsten Behler Photography]](https://opnmedia.blob.core.windows.net/$web/opn/media/images/articles/2025/1025/departments/202510-cover-web.jpg?ext=.jpg)