Originally Posted by
sagesau
Shouldn't the unpowered aircraft have right of way?
Chance as well as consequence of collision is very limited, so it is deemed to be an acceptable risk. The measurement package is more an issue than the balloon itself.
To be visible, it would need to have a transponder which would add a lot of weight. Alternatively, every aircraft would have to be able to receive and interpret the data the probe is transmitting.