In Starbound, Devon and Melissa don’t use the standard space suits that astronauts today utilize. They use what’s called a compression suit, which takes advantage of a really awesome fact, human skin is a surprisingly decent pressure vessel, especially when reinforced with thick layers of cloth. NASA actually experimented with compression suits in the 60’s, eventually developing a prototype, that, quite bluntly, looks really futuristic, but never replaced the existing suit designs due to technical difficulties. You can read about the history of space suits and the, somewhat dense, report on NASA’s experiments below.
Compression Space Suit Overview
Compression Suit NASA Test Report\
Existing space suit designs are essentially a miniature, bubble-boy style space ship. No part of the astronaut is exposed to space. This keeps them safe but also makes it extremely difficult to move your arms and legs. If you’ve seen Neil Armstrong waddling his way across the moon, you can get the idea of how restrictive a fully pressurized space suit is. In fact, the very first space-walk conducted by Russian Cosmonaut Alexei Leonov nearly ended in complete disaster. When he stepped into the vacuum of space, his suit puffed up and stiffened so much that he couldn’t bend his arms to fit back into his capsule.
Fortunately Alexi was an Olympic level gymnast and managed to squeeze himself back inside before his air ran out. Astronaut Space Suits have improved a lot since then, which is why we still use them of course. But why not compression suits?
Truthfully, we probably have the technology to switch to compression suits today. The original issue that sunk the program was that the suit didn't provide enough reinforcement in certain joint areas such as the armpits. This created a slightly low pressure area and led to the tissue swelling up. With modern advances though finding the right balance of support and flexibility is probably far closer that ever before.
Compression suits also have an added advantage that the wearer can breathe a standard mix of oxygen and nitrogen. Current space suits utilize straight oxygen. This has the advantage of providing breathable air at 3.5 psi of pressure, instead of the usual 14 psi you'd find at sea level on Earth. For an astronaut to acclimate his body to 3.5 psi of pure oxygen takes hours. But today space walks are uncommon enough that astronauts can afford to spend hours suiting up and prepping to breath pure oxygen.
As people look towards Mars though, no one wants to spend all day prepping for a stroll outside. There have been some attempts are creating hard shelled space suits to hold higher pressures, but who knows. Maybe in ten years someone will dust off a very old idea, and we'll get our awesome futuristic space suits after all.