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Description

In 1993, the Space Station Freedom program (what would become the International Space Station) faced a combination of cost overruns and budget shortfalls. As a result, an organizational review of the program was conducted, called the Space Station Redesign Study, to find ways of making the station cheaper to build. Three options were presented. Option A and B were fairly straightforward de-scopings of the baseline Freedom design, keeping broadly the same module designs and architecture but cutting less-critical parts (sacrificing capability in favor of cost). Option C, however, was a radical redesign.

The entire US segment of the station was proposed to be combined into a single large module, 7.1 meters in diameter and 19 meters long. It would be launched by an expendable Shuttle-derived sidemount launch vehicle, purpose-built for this one-off mission. This approach would cut the number of launches required (even with the development of the new launcher, and its expendable nature, it was expected to be cheaper than the dozens of Shuttle launches otherwise required), eliminate interfaces between modules, and greatly reduce the amount of on-orbit astronaut labor needed for assembly. Radiators, solar arrays, propulsion, and attitude control systems were all integrated into the core module, eliminating need for a truss structure. Most critically, this single module would have enough volume to accommodate all of the pressurized experiments and facilities desired for the original-scoped Freedom (though unpressurized capacity was reduced).

A few other modules were still planned for inclusion, mostly for geopolitical reasons. JAXA would still provide their Kibo module, ESA would still provide Columbus, and there was also consideration for separate airlock and cupola modules. Still, complexity was drastically reduced, and the effort for these auxiliary modules would mostly be borne by international partners. For expansion and visiting vehicles, the core module provided a total of 4 APAS-95 docking ports and 5 CBM berthing ports

Its fixed solar arrays necessitated a solar-inertial attitude for most operations, shown here

My Freedom Option C 3d model is available on CGTrader

My work is made possible by the support of the community, through patreon.com/brickmack

Description

In 1993, the Space Station Freedom program (what would become the International Space Station) faced a combination of cost overruns and budget shortfalls. As a result, an organizational review of the program was conducted, called the Space Station Redesign Study, to find ways of making the station cheaper to build. Three options were presented. Option A and B were fairly straightforward de-scopings of the baseline Freedom design, keeping broadly the same module designs and architecture but cutting less-critical parts (sacrificing capability in favor of cost). Option C, however, was a radical redesign.

The entire US segment of the station was proposed to be combined into a single large module, 7.1 meters in diameter and 19 meters long. It would be launched by an expendable Shuttle-derived sidemount launch vehicle, purpose-built for this one-off mission. This approach would cut the number of launches required (even with the development of the new launcher, and its expendable nature, it was expected to be cheaper than the dozens of Shuttle launches otherwise required), eliminate interfaces between modules, and greatly reduce the amount of on-orbit astronaut labor needed for assembly. Radiators, solar arrays, propulsion, and attitude control systems were all integrated into the core module, eliminating need for a truss structure. Most critically, this single module would have enough volume to accommodate all of the pressurized experiments and facilities desired for the original-scoped Freedom (though unpressurized capacity was reduced).

A few other modules were still planned for inclusion, mostly for geopolitical reasons. JAXA would still provide their Kibo module, ESA would still provide Columbus, and there was also consideration for separate airlock and cupola modules. Still, complexity was drastically reduced, and the effort for these auxiliary modules would mostly be borne by international partners. For expansion and visiting vehicles, the core module provided a total of 4 APAS-95 docking ports and 5 CBM berthing ports

Its fixed solar arrays necessitated a solar-inertial attitude for most operations, shown here

My Freedom Option C 3d model is available on CGTrader

My work is made possible by the support of the community, through patreon.com/brickmack