5
100 km → 20 km AltitudeLower the First Tether
From the levitated platform, three redundant 0.5mm Zylon threads are lowered 80 km to a stratospheric balloon station at 20 km. This is Stage 2 of the three-stage transport system. Above 20 km, there's negligible wind — the tether hangs nearly vertically. Power flows up via a high-voltage DC conductor woven into the tether. Comms flow via a fiber-optic strand.
Specifications
Tether materialZylon (PBO), 0.5mm × 3 redundant
Length80 km
Total tether mass~72 kg
Breaking strength~4,550 N
Self-weight tension~960 N
Remaining payload capacity~3,590 N (366 kg)
Power delivery10 kV / 0.33A / 3.3 kW HVDC
Open Questions
- ?What's the tether lowering mechanism? Gravity-fed from the platform winch?
- ?How does the tether connect to the balloon station at 20 km? Autonomous docking?
- ?How is the HVDC conductor integrated into the Zylon tether without compromising tensile strength?
- ?What's the failure mode if one of the three redundant threads breaks?