Without a way of knowing which satellite passing overhead was the ISS, in the narrow windows each day where you could see them well enough to correctly point a Yagi at one, you’d quickly run out of battery before making a relevant contact. Also the people on the ISS rarely listen or respond, the most used ham equipment on the ISS is basically a glorified repeater so you’d also have to get above the pileup of all the satellite chasers just trying to log contacts.

JS8Call and FT8 are digital modes that don’t require talking. Plenty of other things to do as well

Fun story, he was killed with a bomb which caused the car he was in to fly so far into the air that he’s often referred to as Spain’s first astronaut.