Surface → 20 km Altitude

Deploy the Balloon Station and Lower Tether

A cluster of stratospheric balloons is deployed to 20 km, forming the relay station between the surface tether (Stage 1) and the ring tether (Stage 2). A Dyneema (UHMWPE) rope is suspended from the balloon station down to a ground station at an equatorial site. This lower tether must survive the jet stream at 10-12 km — the highest-risk segment.

Specifications

Lower tether materialDyneema (UHMWPE), 4-6 mm diameter

Length20 km

Mass200-500 kg

Breaking strength29,400-68,600 N

Jet stream wind load~17,000-26,000 N

Safety factor1.7-2.6× (before fairings)

Ground stationEquatorial — Kiribati, Galápagos, or ocean platform

Open Questions

?What balloon technology works at 20 km for sustained operation? What's the replacement cycle?
?Can aerodynamic fairings on the lower tether meaningfully reduce jet stream loading?
?What's the ground station infrastructure? Anchoring, winch systems, power supply?
?How does the balloon station physically bridge the two tether segments?

Step 5: Lower the First Tether Step 7: First Payload: Self-Reinforcement Begins