The sequined dinosaur toy that rode on SpaceX's historic launch was the winner of a vote by the astronauts' young sons

Astronauts Bob Behnken and Doug Hurley both have young sons who are "super interested in dinosaurs," Behnken said, so they gathered all the dinosaurs in their houses and had the boys choose one to go to space.
The winner, a toy apatosaurus called Tremor, began floating around the spaceship once it reached zero gravity.
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NASA astronauts Bob Behnken and Doug Hurley who made history on Saturday when they became the first people to fly a commercial spacecraft have revealed the story of the mysterious stowaway on their flight: a sequined dinosaur plushie.

"It was not just Doug and I who accomplished the launch here. We do have an apatosaurus aboard," Behnken said after the launch.

When the two astronauts launched atop a Falcon 9 rocket, they became the first to fly SpaceX's Crew Dragon spaceship. If successful (the capsule still has to return them to Earth safely after their stay on the International Space Station), the mission is poised to restore the US's capability to launch humans into space .

spacex crew dragon dinosaur toy plushie demo 2 bob behnken NASA TV

The sparkly plush toy served as a "zero-gravity indicator": It wasn't strapped in, so once the dino started to float around, the astronauts and other observers knew the ship had left the pull of Earth's gravity. The toy was the latest in a long line of plushies that have flown on spaceships for this purpose.

To pick their crew mate, Behnken said, the astronauts turned to their kids.

"We both have two boys who are super interested in dinosaurs, and we collected up all the dinosaurs between the two houses, and Tremor the apatosaurus got the vote from the boys to make the trip into space," he said.

spacex astronauts crew dragon families NASA TV

About 10 minutes after liftoff, as the spaceship was maneuvering into its position in Earth's orbit, the dinosaur toy appeared in NASA's live feed of the Crew Dragon, where it was floating around the cabin of the spaceship.

The plushie is a TY Flippables Tremor Dinosaur , which is no longer manufactured.

The astronauts spent 19 hours in the capsule which they named "Endeavour" before reaching the space station. During that time, they ate, slept, tested the spaceship's systems, and broadcast livestreamed updates from the ship. The shiny dinosaur drifted in and out of view.

spacex dinosaur crew dragon demo 2 astronauts bob behnken doug hurley NASA TV

"That was a super cool thing for us to get a chance to do for both of our sons, who I hope are super excited to see their toy floating around with us onboard," Behnken said. "I'm sure they would rather be here, given the opportunity, but hopefully they're proud of this as well."

SpaceX's previous zero-gravity indicator, a plushie Earth called "Buddy," was on the Crew Dragon's uncrewed test flight the demo that showed the spacecraft was ready to fly people. The toy Earth stayed on the space station after the capsule returned to Earth.

After the Crew Dragon docked to the space station on Sunday, Behnken and Hurley joined the other astronauts and cosmonauts on board. They will stay there for up to 110 days before boarding the Crew Dragon once again for a fiery fall through Earth's atmosphere and, hopefully, a safe splashdown in the Atlantic Ocean. It's not yet clear whether Tremor the apatosaurus will come back with them.

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