Plain-language answer: ARISS supports amateur-radio equipment, educational contacts, and occasional operating activities aboard the International Space Station.
Why the definition matters
Voice, packet, SSTV, and scheduled school contacts depend on current equipment status, crew operations, and published activity—not on the ISS simply being overhead.
Use the number correctly
Check current ARISS status and frequencies, calculate the pass, follow activity-specific guidance, and keep transmissions brief and disciplined.
The common mistake
Transmitting during a scheduled educational contact or using an old mode announcement.
Measurement and safety boundary
Keep reference units, bandwidth, detector, direction, averaging, and test conditions attached to every number. Current regulator requirements and the complete installed system control RF-exposure compliance.
