From an article at space.com :
“Space lingerie is one of the major components of psychological support which we provide to women in orbit,” Yarov said. “The goal of this support is to make women on board feel like women, not just astronauts or cosmonauts. Shannon Lucid and Elena Kondakova liked their lingerie very much.”
Psychological support? Don’t know about that. Those granny panties look ugly and uncomfortable at the same time.