Another successful Blue Origin landing, another tortoise. Let us explain.

Blue Origin’s New Shepard rocket and crew capsule launched Wednesday in West Texas, and both the rocket booster and crew capsule landed successfully after a test of the capsule’s escape system.

The aerospace company started by Amazon founder Jeff Bezos plans to use its New Shepard rockets to take people into space in 2018 for short trips to the Karmin Line, i.e. the border between the Earth’s atmosphere and outer space. But first, it needs to perfect the capsule.

After each landing of Blue Origin’s New Shepard crew capsule, a tortoise was painted on the door with the date of the test mission. The most recent launch and landing was this capsule’s seventh and final trip, so only seven turtles will grace the door. The rocket booster that carried the capsule also saw its fifth-and-final trip.

“We will in fact reward it for its service with a retirement party and put it in a museum,” Bezos said before the launch of the rocket booster.

But back to those capsule turtles. Blue Origin’s turtle fixation isn’t random. The company’s coat of arms prominently features two turtles reaching toward space, with the Latin motto “Gradatim Ferociter,” or “step-by-step, ferociously.” Blue Origin is famously careful with its launches and media access, so the allusion to the classic “Tortoise and the Hare” story is fitting. We wouldn’t venture a guess as to who the competing hare might be.

While this may have been the last flight for this particular New Shepard capsule, chances are pretty good that future capsules will still have turtles painted on them after successful missions. Bezos is a big fan of the company’s motto (he even has a pair of boots featuring the phrase), so the next capsule will probably get the turtle treatment, too.

Photos via Blue Origin