It looks like Ripley won't be flying solo after all — the dummy passenger on SpaceX's Crew Dragon will have a "Celestial Buddy" along for the ride.

"Super high tech zero-g indicator added just before launch," the SpaceX CEO tweeted Friday (March 1) about three hours before the planned liftoff of the Crew Dragon's first uncrewed test flight to the International Space Station.

The mission, named Crew Dragon Demo-1, will lift off from NASA's historic launchpad 39A at the Kennedy Space Center in Florida today (March 2) at 2:49 a.m. EST (0749 GMT). You can watch the launch live here.

Related: SpaceX's Crew Dragon Demo-1 Test Flight in Pictures

The last-minute addition to the Crew Dragon spacecraft isn't exactly a high-tech piece of equipment. It's a soft plush of planet Earth that's about the size of a basketball with an adorably astonished look on its face. Asked by one Twitter user whether the plush would contain any sensors, Musk replied, "He is the sensor!"

Rather than record any actual measurements, the little Earth plush will start to float around once the Crew Dragon spacecraft begins to experience weightlessness, or microgravity. (The term "zero gravity" is a bit of a misnomer, because the Crew Dragon, the International Space Station and anything orbiting the Earth is still subject to the planet's gravitational pull.)

Made by a company called Celestial Buddies, this Earth plush is part of a whole collection of plush planets and moons that space buffs can snuggle with. You can buy the Earth plush on Amazon here for $33.