How to Get
The Interstellar Radio is found in The Distant Spring where it is located inside a Puffy Blowhog floating over a lake and near three Water Dumples. Olimar is forced to fight the beasts with only Blue Pikmin since other types of Pikmin are unable to survive in water.
"I've found my Interstellar Radio! Not only does it emit a constant S.O.S. signal, it also broadcasts voices from space that will brighten up my moments of boredom. The Dolphin, while comfortable, becomes quite a lonely place in the depths of the night..."
"This part will send out a daily S.O.S. signal. I have so little time remaining, though, that I have no option but to continue my search rather than waiting for a rescue party. Having to collect every part is a bit overwhelming...but I get the impression not all parts are needed to fly the ship."
Click on a ship part