The all-girl pop-rock trio called the Pussycats (frontwoman Josie, dumb drummer Melody, and guitarist Valerie), along with their pal Alan, manager Alexander Cabot III, his sister Alexandra Cabot, and cat Sebastian, are accidentally launched into the depths of outer space where they have lots of wild and exciting adventures. Their antics are interspersed with songs performed by the trio, of course, and - this being the Seventies - we even have an appearance from their space 'mascot' (what the hell is he?) Bleep, aka the Cute Little Pet Which Doesn't Speak But Gets In All Sorts Of Wacky Shenanigans (I'm going to trademark that phrase).
There isn't really much more to tell about this series: it was very similar to the previous Josie and the Pussycats cartoon, except the band's adventures take place on faraway planets involving far-out aliens. Its art style, writing, and tone are very similar to other fantasy-based cartoons of the era, including Space Ghost, Herculoids, etc. There were only one season's worth of episodes produced; its next season would be all-reruns.
This didn't stop kids from loving it, of course. When I was small, I saw a promo for this as an upcoming series, sort of a bumper between episodes of another program on the same network. I got so excited just by this little commercial that I immediately ran into the other room where my mother was talking with a friend, blurting out, "Josie and the Pussycats - in Outer Space!" The two women were much amused by my genuine enthusiasm.