Receive voice, SSTV and APRS from the International Space Station using an RTL-SDR and a simple Yagi antenna. Capture an SSTV image during a crew activation event.
Use Gpredict or heavens-above.com to find ISS passes above 30° maximum elevation in the next 48 hours. Note the AOS (acquisition of signal) time and azimuth.
Look at ariss.org or amsat.org for currently active frequencies: voice downlink 145.800 MHz (FM, Doppler), APRS 145.825 MHz, or SSTV events on 145.800 MHz. Activations vary; SSTV campaigns happen a few times per year.
A 3-element 2 m Yagi can be built from scrap aluminium tube or even measured ribbon cable. Connect to the RTL-SDR through the shortest possible coax. Aim horizontally at AOS azimuth.
Tune to 145.800 MHz, bandwidth 15 kHz FM, enable squelch ~20 dB SNR. Route audio through VB-Cable (Windows) or PulseAudio (Linux) to your SSTV decoder.
At AOS the ISS appears ~3.5 kHz high of rest frequency; at LOS it is ~3.5 kHz low. Either run SDR console in "Doppler track" mode via hamlib, or adjust tuning every 30 s manually.
Start recording audio at AOS and keep tracking until LOS (~10 minutes max). If voice is active, you should hear clearly over the noise at max elevation. If SSTV, feed audio to MMSSTV/Robot36.
MMSSTV will auto-detect the encoding (usually PD-120 or Robot 36). An image builds over ~3 minutes. Save the decoded image and submit to ariss-sstv.blogspot.com for your entry into the gallery.
Next pass, try pointing and tracking with elevation too (handheld Yagi is surprisingly effective). Listen for other satellites: NOAA APT on 137 MHz, weather birds, or SO-50 transponder passes with a FM rig.