“Are the suits needed for short space walks or would the [spiders] be wearing them semi-permanently?” another user asked. “This will determine if the suit needs air, heat, and durability to elements.”

The suggestions went on, and in great detail. Users discussed all aspects of spider physiology, from exoskeletons and joint movement to respiratory and circulatory systems. They wondered which space-suit designs would provide the many-limbed creatures with maximum mobility and comfort. One user even suggested that the spiders take some anti-nausea drugs while in zero gravity, as astronauts do.

Read: Tiny jumping spiders can see the moon

The discussion now resembled something other than the dog-in-pants scenario: the very real conversations, decades ago, between engineers and scientists about how to make space suits for human beings. Those deliberations were not so different from the ones in the science-fiction forum, because they were both trying to answer the same question: How do you keep something designed to live on Earth alive in space?

In the United States in the 1960s, the space-suit business was booming. NASA was in the market for a variety of outfits for its first classes of astronauts, for use inside and outside space capsules and, eventually, on the surface of the moon.

According to ILC Dover, the Delaware-based company that designed the iconic Apollo space suits worn by Neil Armstrong and Buzz Aldrin, engineers put different fabrics through rigorous tests to find those that would protect wearers from the extreme conditions of space. They exposed them to sweltering heat and bone-chilling cold, and folded and creased them every which way, bending them at each joint to see how the material would hold up.

Engineers also had to figure out how to prevent conditions inside the space suit from killing the wearer. They needed life-support systems that would circulate oxygen throughout the suit, and remove excess heat and carbon dioxide and eject them into space. If temperatures in the suit rose, astronauts could become dehydrated. If exhaled carbon dioxide accumulated, they could die.

On top of that, engineers had to determine exactly how much life support astronauts would need. “At the start of 1962, a significant challenge to the development of the Apollo [ Extravehicular Mobility Unit] was lack of a detailed understanding of the metabolic performance requirements of a man in a suit,” according to NASA. “No one in the U.S. space community knew the correct requirements.”

Decades after humans proved that they could survive in space with the right outfit, engineers are still working on space-suit designs. Boeing and SpaceX, which are expected to launch American astronauts to low-Earth orbit next year as part of a NASA program, have spent the past several years designing space suits of their own. Both are pressurized suits designed for the in-flight experience, not space walks. Boeing’s cobalt-blue suit comes with a zipper down the back for entry; a soft, hoodlike helmet; and footwear that resembles sneakers, a departure from the traditional, bulky boots of the past. SpaceX’s white-and-black space-suit design resembles that of a Power Ranger or Stormtrooper suit, with tall, rain boot–like shoes and a traditional, motorcycle-esque helmet.