Guest star Michelle Collins in Radio Times

"We were running around in vests and combats, covered in baby oil and sprayed with water. It was very uncomfortable, because baby oil makes you feel really yucky, and I had to have it on my hair and hands, and my hands had to be filthy."

Not a typical role for the ex-EastEnder then - light years from Walford, in fact, as Collins's ship is heading for a distant sun. So the atmosphere is necessarily hot, hence the spray to give the actors that dripping-with-sweat look. "You got used to it," says Collins. "It was quite liberating not wearing even a bit of mascara, because if I had done it would have been all over my face in two minutes. I was a bit worried about that no-make-up look to start with, then I just thought, 'Oh, go for it!'"