Leaving her family behind is the toughest part for Hong Kong’s first astronaut Lai Ka-ying as she blasted off on Sunday for her six-month mission, according to her elder sister.

Lai Ka-man recalled that when the 43-year-old Hong Kong police superintendent was selected as a payload specialist in 2024, her three children were still in primary school, and are now being cared for by both sets of grandparents and other family members.

“When I saw my sister recently, I felt in her gaze that she was even more determined than before,” the astronaut’s sister told mainland Chinese media.

She added that the family was worried the astronaut would miss them too much.

“We hope she will be careful in everything she does while on the mission,” the elder Lai said.

Lai Ka-man said that her astronaut sister gave herself the moniker “big bee” because she enjoyed working hard and being part of a team.