This story was updated at 6:36 p.m. ET.
An American astronaut getting ready to ride a Russian Soyuz spacecraft home early Friday said she's excited for what's rumored to be a pretty wild ride.
"I've heard it described as a train wreck followed by a car crash followed by falling off your bike," NASA astronaut Tracy Caldwell Dyson said in a prelanding video. "But honestly I think that's just folks trying to find a bit of humor in a hard landing, which I understand the Soyuz is."
Caldwell Dyson is wrapping up a nearly six-month stay on the International Space Station. She will depart the station tonight (Sept. 22) with two of her crewmates: Russians Alexander Skvortsov and Mikhail Kornienko. The spaceflyers boarded their Soyuz TMA-18 spacecraft on Thursday and closed the hatches between it and the space station at 6:35 p.m. EDT (2235 GMT).
The trio is slated to land on the steppes of Kazakhstan in Central Asia tomorrow at about 12:55 a.m. EDT (0455 GMT).
It will be Caldwell Dyson's first journey down to Earth aboard the Soyuz, which is said to be a somewhat rougher landing compared with the long glide and runway landing of a NASA space shuttle.
Unlike space shuttles, Russia's Soyuz spacecraft are three-module capsules. During a descent and landing, the Soyuz crew capsule separates from its propulsion and orbital modules (which are no longer needed), then deploys a parachute. [ Photos: One Soyuz Spaceship's Snowy Landing ]
Just before touchdown, the Soyuz fires a set of retrorockets to slow its landing even more before coming to a jarring stop on the ground. Sometimes, the capsules can tip on their sides after landing.
"I've heard so many stories from people describing what landing is like and all I can say is, I'm going to expect this to be Mr. Toad's Wild Ride for me," Caldwell Dyson said in the NASA video she recorded on the station.
She recalled a conversation she had with NASA astronaut Michael Foale, a veteran Soyuz rider, right before she launched on her mission.
"It was a very interesting conversation, as we talked about, 'Yeah, at this point you're going to hear a bang and then you're going to feel this jolt and then you're going to kind of smell this interesting odor as the oblation material starts to burn off,'" Caldwell Dyson said. "And anybody sitting outside this conversation would have thought we were mad."
The departing spaceflyers are slated to undock from the station Thursday at 9:35 p.m. EDT (0135 GMT Friday).
Caldwell Dyson said leaving the station would be bittersweet, but she was mostly excited to experience a Soyuz landing for the first time.
"That level of anticipation is really just provided to me by my fellow crewmates who have gone before me, and so I hang on to their descriptions and I look forward to experiencing this, to a large degree," she said. "There's a small degree of me that says, 'you know there are some key things, make sure your straps are tight, you've got your head back and your tongue is not between your teeth when you land.'"
- Video: Astronaut Describes Riding Home on a Rocket
- Gallery - Soyuz Spaceship's Snowy Landing
- Images - Space Station's Windows on the World
NASA will broadcast the upcoming Soyuz spacecraft undocking and landing live on NASA TV, beginning at 5:45 p.m. ET. Undocking and landing coverage begins at 9:15 p.m. ET (0115 Sept. 24 GMT). Click here live space station mission updates and a link to NASA TV.