The Lego set floated nearly 35km high and spent over eight hours in the air before returning safely back to Earth, all caught on video.
Keeping the pieces together at that altitude wasn't easy, making this achievement even cooler.
If you want to check out more about this wild journey or see the video, head over to the Guinness website.
And if you're still curious about Project Hail Mary, it's playing in theaters now!