I mean...
Supernova = stars exploding, makes sense...
Pulsar itself is a type of star that rotates and shoots stuff out...
Polaris = the north star
Wildfire = something that happens on earth and has nothing to do with space
Permafroster = Another thing that happens on earth and has nothing to do with space
Sim-Kay suggested Aurora for the Ice one and Quasar for the fire one, and I think those are both fitting names, though I'd still prefer something a bit more 'stellar' for the ice polaris. Perhaps Blueshift?
Comets are literally balls of ice, so something like that could be possible? Blueshift is neat but it's kind of more.. moving/speed-based than temperature. I love the word, don't get me wrong, but I personally don't feel that it's very fitting. (Maybe on an ice-themed item that increases MSI/ASI!)
I hadn't realized that these were missed opportunities for space-themed names!
Other ideas:
Comet-inspired names like Haley's Shot or even just Shooting Star. That's almost too punny. :C
My friend suggested Red Giant and Blue Dwarf, both fitting AND they keep the theme even more specific - stars, rather than just general space.
/brainstorming now, I'M SORRY I JUST REALLY LIKE SPACE
edit:
Also because I really like one-word names for stuff:
http://en.wikipedia.org/wiki/Europa_(moon)
http://en.wikipedia.org/wiki/Enceladus
the ice and fire of Jupiter and Saturn, in a sense, Europa is covered in water ice and Enceladus is so hot in its core that it shoots geysers into space. We could probably go more for Mercury or Venus though since that's more known that they're quite hot, temperature-wise.
Solar Flare is also a pretty evocative fire name.