SpaceX has a "go" from NASA to launch Crew Dragon, a new commercial spaceship for astronauts, on Saturday at 2:49 a.m. ET.

The rocket launch won't send any people to space, but SpaceX is launching 400 lbs of cargo and a crash-test dummy.

On Thursday, SpaceX revealed the mannequin has a female body and spacesuit. It is named "Ripley" after the lead character in the "Alien" sci-fi horror movie franchise.

NASA said the dummy is part of its plan to "instrument the crap out of" Crew Dragon to verify that it's safe to fly astronauts.

This story has been updated with new information.

CAPE CANAVERAL, Fla. — SpaceX is moving quickly toward one of the most important launches in its 17-year existence: The first launch of Crew Dragon, a spaceship that Elon Musk's aerospace company designed to fly NASA astronauts into orbit.

Crew Dragon is part of NASA's roughly $8 billion Commercial Crew Program, which was created to restore the agency's ability to launch people to the International Space Station. (NASA retired its space shuttle program in July 2011, and has been sending astronauts on Russian Soyuz spacecraft since then.)

NASA has given a "go" for Crew Dragon's inaugural launch aboard a Falcon 9 rocket on Saturday at 2:49 a.m. ET. The mission has a roughly 80% chance of good weather for launch, according to a forecast issued Thursday.

Read more: SpaceX will launch its Crew Dragon spaceship into orbit for the first time ever on Saturday. Here's how to watch live.

For this experimental mission, called Demo-1, SpaceX won't launch any of NASA's finest to the International Space Station. Instead, it will send 400 pounds of cargo and a crash-test dummy wearing a spacesuit.

Hans Koenigsmann, SpaceX's vice president for build and flight reliability, revealed during a press briefing on Thursday that the dummy will have a female body and spacesuit.

"It has lots of sensors. We call it a smarty, and her name is Ripley," Koenigsmann said. The name is an homage to Ellen Ripley, the lead character in the film "Alien" played by Sigourney Weaver.

Why 'Ripley' is a critical part of SpaceX and NASA's mission

A view of SpaceX's Crew Dragon capsule atop a Falcon 9 rocket in Cape Canaveral, Florida. The spacecraft is part of NASA's Commercial Crew Program to launch astronauts into orbit from US soil. SpaceX/Twitter

The reason a mannequin was chosen to go to the ISS first was so that the lives of astronauts are not put at risk; Crew Dragon may still have quirks that aren't fully understood.

"This is an invaluable exercise to learn, in the space environment, how these systems will be working," Kathryn Lueders, the manager of NASA's Commercial Crew Program told Business Insider.

"We've done tons of water-landing testing, parachute testing — all of these individual pieces. But actually having a reentry with Ripley in the seat, in the position is critical," Lueders said. "We've instrumented the crap out of this vehicle."

Musk shared the first public photo of Ripley via tweet early on Friday morning, and it shows the spacesuit-clad figure — what NASA officially calls Ripley an "anthropomorphic test device" or ATD — reclined in a seat of the Crew Dragon vehicle (below).

In preparation for the inaugural launch of its Crew Dragon spaceship, SpaceX put a crash-test dummy in one of the vehicle's seats. The mannequin is named "Ripley," named after the lead character in the sci-fi movies "Alien." Elon Musk/SpaceX via Twitter

Lueders said the dummy will monitor sudden changes in speed that can induce artificial gravity, or G-loads. If those forces are too strong, a Crew Dragon astronaut could get knocked unconscious or possibly injured.

Ripley and other sensors on board Crew Dragon will also measure temperatures, listen for harmful noise levels, and make sure the spacecraft isn't vibrating too much at any point in the mission.

SpaceX's Dragon v2 floats to Earth during a parachute test. SpaceX/Flickr (public domain) "Just like you do car testing, it's going to measure all of the responses. Ideally the whole environment will be really gentle and easy, but we do know that when you're landing under parachutes, those landings can be hard," Lueders said. "We obviously do a whole bunch of testing in lots of different ways, but they kind of frown on using people in an unproven vehicle."

The space station crew will meet Ripley after she arrives, approximately 27 hours after launch.

"Looking forward to meeting her in person," Anne McClain, a NASA astronaut and current ISS crew member, told Musk on Twitter.

Once Ripley is back on the ground, Lueders said engineers will feed her data into computer simulations to model how Crew Dragon might behave in a variety of situations with real people on board.

If all goes well with Demo-1, SpaceX will then do an in-flight test of an abort system as soon as April. After that, SpaceX hopes to launch its first astronauts on its Demo-2 mission.

"Every mission is important, but [Demo-1] is even more important. I'm pretty sure it's not just me. I'm pretty sure everybody at SpaceX feels this way," Koenigsmann said.

This story has been updated with new information.