The very idea of a space elevator sounds like it was ripped from the pages of a 1950s sci-fi pulp magazine with a title like Thrilling Wonder Stories or Fantastic Adventures, a publication filled with tales of jet-packed intergalactic travelers living on lunar colonies.

But an Earth-based space elevator—essentially, a transportation system involving a climbing craft ascending and descending a cable tethered to the ground and extending past geostationary orbit—is a concept scientists have been seriously considering for almost as long as industrial-era elevators have been around. Thanks to innovations in nanotubes and other technological areas, such an invention might actually become a near-future reality.

Four representatives of a venture determined to see the human race reach the stars with a “going up, please,” instead of a “blast off,” answered questions Wednesday about space elevators during an Ask Me Anything session with Reddit’s Ask Science community. This quartet is behind a space elevator documentary, Sky Line, and come from varying backgrounds:

Jerome Pearson, an aerospace engineer; a leading pioneer in the space elevator field who Arthur C. Clarke consulted before the 2001: A Space Odyssey author wrote his award-winning, 1978 novel about the construction of a space elevator, The Fountains of Paradise; and the president of STAR Inc., a company that specializes in air and spacecrafts

Ted Semon, a retired software engineer and past president of the International Space Elevator Consortium who also writes at The Space Elevator Blog

Miguel Drake-McLaughlin, a filmmaker and the co-director of Sky Line

Michael Laine, founder of LiftPort Group, a company that has been working on building a space elevator since 2002

These space elevator evangelists shed light on the science behind this theoretical mode of transportation and debated skeptics who said the idea is still the stuff of sci-fi books and movies. Here are some of the highlights from the AMA.

Is a Space Elevator Really Possible?

Why Build a Space Elevator?

Would Space Junk Damage the Elevator?

What About Bad Weather?

What Would Travel Time be Like?

How Would a Space Elevator Be Fueled?

How Much Could a Space Elevator Carry?

Do Strong Enough Cables for a Space Elevator Exist?

What About the Space Elevator’s Neighbors?

Check out the complete Ask Me Anything in the Ask Science community for more about space elevators.