EOSS - friznit/Unofficial-BDB-Wiki GitHub Wiki
Early Orbital Space Station is a pre-Skylab concept (1967) for an advanced orbital workshop based on the S-IVB stage of Saturn V. The S-II booster stage is jettisoned but the interstage remains attached to S-IVB and the space utilised for scientific and orbital observation equipment. The Interstage Station Module is fitted with a passive docking port under a jettisonable cover for docking an Apollo (BDB Kane) spacecraft.
An alternative concept retained the the S-II to provide space for a crew of up to 9. In this configuration the EOSS could be tumbled end over end to provide artificial gravity.
If launched with a spacecraft above the SLA in the style of Saturn V, the S-IVB Instrument Unit should be set as the root part to avoid issues when decoupling.