As someone who grew up during the ISS program, Skylab was before my time. It came as a surprise to me when I was perhaps fifteen to discover there had in fact been many other space stations before it. I knew about Mir, but not the Salyut project. I had some vague recollection of seeing photos of 1970s era astronauts inside a space habitat, but none of the specifics were known to me until I bothered to learn the history of American spaceflight in greater detail.
Skylab was the entire upper section of a Saturn V rocket. While the Saturn V was still flying, the lifting capacity for putting single payloads into space was considerably greater than that of the shuttle, and will be again when the SLS comes online. Because of this boon, Skylab was dramatically larger inside than any single ISS module. You can get a sense from the diagram I used for this article's cover picture, but even photos don't really do it justice.
The padded ring in the upper half of this image was in fact large enough in diameter that astronauts could jog around it. Compared that to the dismally cramped confines of an ISS module and you begin to get a sense of how much more spacious and liveable Skylab was!
Of course it was only a single module, the total internal volume of the ISS exceeds it. But just imaging an ISS style space station built entirely from modules the size of Skylab? Though we may be headed in that direction with the recent attachment of an experimental inflatable module to the ISS. Inflatables may give us Skylab style interior room, or even greater when paired with a heavy lift vehicle like the SLS.
Skylab was plagued with problems early on, many related to getting rid of excess heat. Space is thought of as cold, but leave a huge metal structure in unfiltered sun for long enough and it'll become lethally hot. Technical issues with the heat exchangers prevented Skylab from dumping heat effectively during the first few weeks, making it into a sweltering oven inside. That was just the first of many glitches that naturally went along with our first baby steps in space station operations.
Skylab consisted not only of the large open chamber already pictured but was divided by a floor such that it had a lower section, which itself was subdivided into rooms for privacy. Rooms where astronauts, slept, bathed and ate their meals, among other functions of every day life.
If ever you have seen 1970s era illustrations of enormous multi-floor space complexes, it's because the illustrators wrongly assumed the Saturn V would either never stop flying or that whatever came after it would be able to lift more at once, not less.
That tremendous lifting capacity made possible all sorts of projects which sadly never saw the light of day because the Saturn V was replaced by the shuttle. One of those proposed projects was the "Lunar Campsite", a single module habitat consisting of the upper stage of a Saturn V (just like Skylab) but sent to the Moon instead of low Earth orbit.
The interior living space would be smaller as some of it would need to be taken up by the fuel tanks needed to land it on the lunar surface, but the resulting habitat would in a single launch establish a permanent manned base on the Moon!
I do not consider the end of the Skylab program to be any sort of tragedy, because NASA went on to build a bigger, better space station. However I do consider it a tragedy that the Lunar campsite habitat was never launched. Because if we'd only done that, it would still be there. Sitting patiently on the Moon, waiting through periods of political turmoil, always ready to receive astronauts during those rare periods when NASA has the money it needs to send some.
This noncommittal approach ideally fits NASA's current uncertain funding situation. When SLS starts flying, we would be wise to spare a single launch to establish a "set it and forget it" modest Lunar outpost like the Lunar Campsite. Even as we send humans to Mars, the Lunar habitat would still be there. Having cost only a single launch to place it on the Moon's surface, we might even allow other space agencies like the ESA or JAXA to rent access to it for their own astronauts.
I am all for a united push to put humans on Mars by 2030. But I don't think a single launch, sending an unmanned habitat to automatically land on the Moon, would meaningfully take away from it. If anything it would permit affordable, limited manned Lunar exploration at the same time. Perhaps it can wait, but the "it can wait" approach is why we're sending astronauts to Mars by 2030 rather than having already sent them in the 1980s.
Meanwhile, what becomes of the ISS? Its lifespan extended out to 2024, we'll be seeing and hearing about it for nearly another decade, but after that? Bigelow's inflatable space station technology seems to be the way forward.
Its massive internal volume will at last make possible the huge, roomy space stations of science fiction, even in single module configurations. Multi-module inflatable stations would be almost so large that I can't imagine a use for all that space. It will become possible very soon though, following the successful attachment and inflation of Bigelow's B.E.A.M. storage module on the ISS, the future for inflatable space habitats is looking very bright.
Illustrations of these inflatable, single module space habitats look at the same time futuristic and nostalgic. Fantastical and forward looking, but also very...familiar. When the next generation of astronauts begins to assemble and inhabit these structures, they will be like the little man who only sees further than others because he stands on the shoulders of giants. Forging their own path into an unknown future, while never forgetting the pioneering triumphs of those who came before.
