in the Rocket city inside the science of episode

ARTIFICIAL GRAVITYTwo of the more astounding – and, perhaps, improbable – things we see in the entire “Star Wars” saga are the Death Star space stations. The man-made globe in Episode IV is supposed to be 100 miles in diameter; the second Death Star in Episode VI, right, is meant to be 600 miles in diameter. How might engineers bring gravity to a space station this size?

I II III IV VIV

ePiSoDe Vi:

Return of the Jedi

Directed by: Richard Marquand

Released: May 25, 1983

First weekend gross: $23.0 million

Total domestic gross: $309.2 million

Total worldwide gross: $572.7 million

Academy Awards: Nominated in four categories, including original score, sound editing and sound mixing. Won none of those awards; however, the movie was given a special achievement award for visual effects.

The good: Leia’s metal bikini. We had to sit through two movies’ worth of frumpy robes to find out what she was packing.

The bad and the ugly: There are too darn many Muppets in this movie: Jabba’s pets and house band, Yoda and those truly annoying Ewoks.

“A bad feeling about this”: 1) C-3PO, as he and R2-D2 enter Jabba’s palace. 2) Han, as the Ewoks attempt to grill him.

Limbs chopped off: Luke slices off Vader’s artificial arm during their lightsaber duel on the new Death Star.

In the epic conclusion of the saga, the Empire pre-pares to crush the Rebellion with a more powerful Death Star while the Rebel fleet mounts a massive attack on the space station. Luke Skywalker con-fronts his father Darth Vader in a final climactic duel before the evil Emperor Palpatine. In the last second, Vader makes a momentous choice: He de-stroys the Emperor and saves his son. The Empire is finally defeated, the Sith are destroyed, and Anakin Skywalker is thus redeemed. At long last, freedom is restored to the galaxy.

Great quote:

“You’ve failed, your Highness. I am a Jedi. Like my father before me.”

- Luke Skywalker

Sources: “The Science of Star Wars” by Jeanne Cavelos; “Star Wars: Where Science Meets Imagination” by National Geographic and the Boston Museum of Science; “Star Wars: The Complete Visual Dictionary” by David West Reynolds and James Luceno; NASA’s Jet Propulsion Laboratory; Wired magazine; StarWars.com; Internet Movie Data Base; www.the-numbers.com; IGN Entertainment; CarrieFisher.com; Lucasfilm Ltd.

images: Courtesy of Lucasfilm

Graphics and research by Charles Apple/Special to The Times Interviews and research by Lee Roop/The Huntsville Times

Leia’s slavecostumeForget the awesome space dogfights and the showdown between Luke and his papa. The thing that fans — many of them pre-teen boys in 1983 — re-member the most about Episode VI is that ... thing ... Princess Leia almost wore as a captive in Jabba the Hutt’s palace.

Costume designer Aggie Guerard Rodgers told Wired magazine there were two versions of the outfit. “One was a hard metal piece that (actress Carrie Fisher) wore when she was not doing any stunts, and one was a rubber piece that we formed so that she would be comfortable when do-ing stunts,” she says. “It was lined with leather so it wouldn’t chafe her body.”

However, the costume didn’t hold together well. Fisher reportedly refused to use the standard remedy for such issues — namely, double-sided tape. As a result, IGN Enter-tainment reports: “Several scenes had to be re-shot when ‘wardrobe malfunctions’ occurred.”

Fisher writes on her website that the outift “had the tendency to make my now not-so-private privates quite public. Especially for the ac-tor standing behind Jabba, playing Boba Fett [Jeremy Bullock]. From where Boba stood, so straight and tall and severe behind his mask — to put it simply and weirdly, Jeremy could see beyond my yawning, plastic bikini bottoms all the way to Florida.”

Sleep on that one, guys!

“When we look at doing missions to Mars where you’ve got a six-to-nine-month travel time on the way out and then the same on the way back, and then living

on the surface in just one-third [of Earth’s] gravity, that’s a concern,” Smither-man says. “There have been missions where we have looked at concepts for

rotating the habitat so you would have at least a one-third gravity on the way out there and higher gravity on the way back.”

The Death Star — and all the other ships in the Star Wars saga, for that matter — “have some type of artificial gravity,” says David Smitherman, a technical manager in NASA’s Ad-vanced Concepts Office at Marshall Space Flight Center and who has a background in space architecture. “We do not understand how they would do something like that, although we would love to be able to do that.

“From my perspective as an architect, what I would look at doing is creating some type of rotational facility where you can generate gravity.”

Jeanne Cavelos, a former astrophysi-cist and mathematician at NASA’s Johnson Space Center and the author of “The Science of Star Wars” says it’s all about acceleration.

“Since acceleration is caused not only by slowing down or speeding up but by

changing directions, an object mov-ing in a circle undergoes a constant acceleration,” Cavelos writes.

“There have been times when I wished movies like that would do scenes where, all of a sudden, the artificial gravity goes out and people start floating around,” says Smither-man. “Because there’s no mass there, so they’re having to generate it through some type of power supply, some way.

“Of course, we don’t understand how they would do that, but if the power went out it seems like that gravity would go out also. And that would be really cool,” says Smitherman.

Remember that scene in Episode IV when Obi-Wan Kenobi realizes it’s a space station and not a moon?

Well, guess what: See that photo at left? That’s not the Death Star – that is a moon. Of Saturn, to be precise.

It’s called Mimas and is 396 miles in diameter. The circular crater — which, in this picture from NASA’s Cassini probe, does look at lot like the Death Star’s laser weapon — is 88 miles across.

“When I saw that movie I was a stu-dent in Architecture at Auburn Uni-versity,” Smitherman says, “My first reaction was ‘No, no, no, that’s not the way you would build this.’

For movie purposes it looks so cool [but] I would have built a large in-flatable, like a big balloon, so you’d have a pressurized atmosphere, and then go inside and build this thing.”

Presumably, Smitherman would also have advised the Empire to do something about the thermal exhaust port where Luke Skywalker fires his torpedo.

Nature imitates artWhat would be really cool ...

An attractive problem

“If we envision a spaceship as a giant, rotating, hula-hoop-type tube with the passengers inside the tube, the rotation would push them against the outermost part of the tube” Cavelos writes.