BULL

BULL is a Japanese startup developing HORN, a low-cost post-mission disposal device that is fitted to a spacecraft or launch vehicle stage before flight and deployed once its mission ends. A thin resin membrane unfurls like a sail from an extended boom, catching the residual atmospheric drag found at roughly 600 to 800 kilometres altitude to decelerate the object so it loses altitude and re-enters, rather than lingering in orbit for decades.

The approach targets debris prevention rather than debris removal: because the hardware launches with the spacecraft, it avoids the cost and complexity of a separate rendezvous mission. BULL also markets on-orbit services built on the same technology.

BULL signed a memorandum of understanding with Arianespace in 2024 to study fitting HORN to the Ariane 6 dual launch system, with candidate launch slots identified from 2027, and has run co-creation activities with JAXA on a device for the Epsilon S launch vehicle upper stage. In April 2026 it signed a basic agreement with Fujitsu to develop a high-precision Japanese space situational awareness service.