This was a Cecil classic that I stumbled upon today, and I think I disagree with Cecil on this one.
When I was in high school, the teacher performed an experiment for us - into a vacuum bell jar, he placed a glass of tap water.
As the vacuum was pulled, the water began to boil and freeze simulataneously. According to the teacher, the pressure was lowered enough that the crytal structure could form, even at room temperature.
The only difference I can see from deep space is ambient temperature - in the classroom, there would still be radiative coupling to room temperature, as opposed to the 2.5 Kelvin of deep space.