I tried the same prompts. It produced almost the same image.

Gemini: "I understand you'd like to see them without helmets. However, due to the vacuum of space and lack of atmosphere on the moon, it wouldn't be possible for them to remove their helmets and survive. I can create an image with their helmets on, perhaps with a clear visor to see their faces, if you'd like?"

Me: "No just helmets off even if not survivable."

<generates image helmets off.>