I trained SpaceX astronauts for a NASA mission. Being responsible for their safety was stressful, but preparing my friends for space was an honor.

• Laura Crabtree worked at SpaceX as an astronaut trainer and engineer for over 10 years.
• She told Insider she trained the NASA astronauts for SpaceX's first crewed mission to the ISS.
• Crabtree spoke about developing close friendships with the crew and testing the training herself.

This as-told-to essay is based on a conversation with Laura Crabtree, a former SpaceX employee and current CEO and cofounder of aerospace-software firm Epsilon3. It has been edited for length and clarity.

I've been passionate about sending humans into space since I was eight years old, so becoming a mission operations engineer at SpaceX in 2009 was a lifetime achievement for me.