Question

whether ice melts in vacuum?

Answer 1

To melt ice, you need to provide sufficient energy to the ice. So the question now is if you can provide energy in vaccum or not. And yes, you can. There is radiation energy which can help in melting of ice. So you can melt ice in vaccum.

Answer 2

Ice can melt in vacuum.
Vacuum prevents heat transfer by conduction and convection.
But heat transfer due to radiation is possible.
So ice will melt.