Arguably, man-made climate change represents potentially greater peril than global thermonuclear war. Carbon-free renewable-energy transformation, previously “economically beneficial,” becomes essential. Pending Earthbound thermonuclear power, stellar (solar-generated) hydrogen offers optimal alternatives. Given real-estate, 2-axis-tracking medium-solar-concentration (100-300sun) photovoltaic/thermal hybrids maximize multijunction efficiencies, providing residual industrial-heat continuously/daily—excluding concentration-prohibiting atmospheric/meteorological interference/diffusion/defocusing .

SSOLAEROS’s unencumbered "real-estate"—23km/75,400ft, above cloud/dust attenuation, aviation corridors, jet-stream turbulence and 97.34% atmosphere—delivers uncompromised 1.37kw/m² temperate-zone high-altitude insolation 10-15hrs/day with vast heat-sink/cooling: constant 220K/-53ºC/-64ºF. State-of-the-art long-duration, high-altitude, station-keeping balloons/semi-rigid-inflatables accommodate stratospheric 40X-100X-volumetric-expansions but suffer “cube/square-laws” AND “Hindenburg Horrors.”

As balloon/blimp/dirigible dimensions increase linearly, lifting-gas-envelope surface-area/weight grows square-wise, volume/lift cube-wise —mandating “bigger-is-better.” But manned balloons “require” nonflammable helium—currently US$2.90/m³—prohibitive for ultra-large LTA-inflatables; unmanned balloons can employ lighter/cheaper hydrogen. Synergistically isolating/insulating hydrogen-lifting-gas facilitates directable/(dirigible) semi-rigidity employing inert-nitrogen-inflated skeleton/shells (“skells”) surrounding/protecting hydrogen: bricks-in-the-wall, each 22mLx2mWx2m-“thick”x3.6μm-“thin”-UV-resistant polyethylene. N2-overpressure (not internal H2) insures semi-rigidity: 9,984 of total 13,504 solar-transparent skells, initially stowed radially, (accordion-style,)—inside 3,520 reinforced/reflective "external-hull"-skells—unfold/expand 46-fold at 23km-pressures to 240m-diameterX796m-length.

Fuller's mathematics/geometry facilitates such gigantic (not massive) structural-integrity. Architecturally, ‘tensegrity’ structures "employing contiguous tension-elements connecting discontiguous compression members" provide "phenomenal-yet-flexional rigidity." Similarly, TensAirity® buckling-countering inflation-tensioned cabled/envelopes surround long/thin-compression-members. SSOLAEROS’ telescoping core/keel/’spine’-endoskeleton biomimimetically augments skell-envelope/exoskeleton, every 6th circumferential-skell surrounding stiffening/reinforcing TensAirity-members incorporating 15%-overpressured compression-tubes, inside 10%-overpressured TensAirity-members, inside 5%-overpressured skell-envelope enclosing atmospheric-pressure hydrogen.

Contracted/infolded to hangar-dimensions allows assembly/maintenance in decommissioned dirigible-hangars. Expanding/extending to slim 94m-Diameterx864m-Length minimizes drag ascending passively through jet-stream winds. 138,240m²/34-Acres, 240m-Diameterx576m-Length, intercepts 190Megawatts/1.9-2.8Gigawatt-hr/day electrolysis energy.

Each (9,984) 22m-longx2m-wide transparent-skells’ inner-surfaces stow/deploy congruent reflector-pairs—22m-longx100cm-widex30μm-thick/92gram tension-framed aluminized Mylar® strips. Fast-response imaging-chip-driven peizo-steppers orient individual ‘sun-side’ strips parallel to incoming solar-rays—like ‘opened-slat’ Venetian blinds—or, reflector-side, as single-axis, active-tracking Fresnel-reflectors. (SSOLAEROS’ own geo-orientation provides ‘slow-axis’ solar-tracking.) Reflected rays diverge 0.53º (solar angular-diameter) from 100cm-wide reflectors, spreading 155cm over 120m-radius to 4m-diameter core/keel’s solar-collectors, allowing reduced-precision alignment/response @100-150sun-concentration.

At core/keel-focus, un-fanfolded/deployed, efficient, transparent-backed solar-collectors capture 29-44% photovoltaically. Unabsorbed bands/wavelengths pass to thermal-collectors reaching ~900-950K/~675-725ºC/~1250-1340ºF—100-150suns’ theoretic optimum. Photovoltaics’ active-cooling (to 283K/10ºC/50ºF) recirculates liquid-NH3, vaporized at MIMS-printed heat-exchangers, then pre-heats 350-bar/35Mpa/5,162psi-steam, ultimately recondensed below 240K/-33ºC/-28ºF-BP externally at 220K/-53ºC/-64ºF atmospheric.

Solid-Oxide-Electrolyzer-Cells/(SOECs) decompose HPHT-steam (350bar/925K/25MPa/700ºC/5160psi/1300ºF)—“industrial-heat” replacing ~22%-kwhrs versus STP-operation, concurrently obviating H2/O2 storage compression. Highly exothermic H2/O2-liquefaction awaits nightfall: reversed SOECs power refrigeration, reversed diurnal- recuperative Stirling engines feeding magnetocaloric/cryogenic systems, concurrently catalyzing ortho-isomerec to parahydrogen product. Direct lifting-gas waste-heating matches daytime densities, avoiding nocturnal altitude-losses typifying non-superpressurized inflatables.

Ascent-process reverse: after 4-6 days—400,000kg H2O converted to H2+O2.