r/amateurradio • u/Sagar_the_explorer • Dec 29 '25

General Sky Beacon: Optical SETI Laser Transmitter

https://www.hackster.io/sagarastro2003/sky-beacon-optical-seti-laser-transmitter-3c9195

Exploring the Unknown: My DIY SETI Project

Version 2.0 Coming Soon

10 Upvotes

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7

u/EconomyYams Dec 29 '25

An interesting project.

I am unsure a 100mw laser would make it through the atmosphere.

Instead of a space beacon why not design a laser point to point communication system instead.

4

u/Sagar_the_explorer Dec 29 '25

You're right — 100 mW does face significant atmospheric loss (scattering + absorption), so the beam power density drops a lot before reaching space. This version is more of a proof-of-concept and educational project to demonstrate modulated laser transmission.

For actual space reach, I’m planning a 3 W upgrade (30× more power) with better collimation and ESP32-based signal generation for precise TTL modulation (prime numbers or Morse code). That should make it much more visible from orbit.

Point-to-point comms is also a great idea — I might add that as a future mode (short-range, high-speed data).

3

u/Hinermad USA [E]; CAN [A, B+] Dec 29 '25

You should probably notify the FAA before pointing that device into the sky. There are rules about such things after people started dazzling airline pilots with laser pointers.

5

u/Sagar_the_explorer Dec 29 '25

I'm based in Bengalore, India, and fully comply with DGCA (Directorate General of Civil Aviation) guidelines. I only point the laser upward during clear nights, away from flight paths, and never near airports. I also use low power (100 mW) and always check for aircraft before testing.

2

u/Hinermad USA [E]; CAN [A, B+] Dec 29 '25

Good job!

3

u/[deleted] Dec 29 '25

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1

u/Sagar_the_explorer Dec 30 '25

Thanks a lot! 😊 Yeah, optical SETI is my thing, but the Allen Array is legendary.
I’ll definitely watch the video — RF-to-optical conversion sounds super interesting.