BULL Inc. to Demonstrate Space Debris Mitigation (PMD) Device 'HORN' on EnduroSat Satellite in Orbit

BULL Inc. (Headquarters: Utsunomiya City, Tochigi Prefecture, Japan; Founder & CEO: Kyoshi Uto, hereinafter "BULL"), a company engaged in space debris mitigation, announces the conclusion of a contract with EnduroSat (Headquarters: Sofia, Bulgaria; Founder & CEO: Raycho Raychev, hereinafter "EnduroSat"), a global space infrastructure builder with operational experience of over 100 satellites worldwide, to conduct an in-orbit demonstration (※2) of BULL's Post-Mission Disposal (PMD) device 'HORN' on a 16U-sized satellite (※1) manufactured by EnduroSat.

BULL's PMD device 'HORN' will be launched into orbit in 2027 aboard an EnduroSat satellite and will demonstrate successful deployment and orbital decay under actual space conditions as designed. The satellite will be launched in 2027 via SpaceX's 'Transporter-22' rideshare mission (※3).

This demonstration represents a major step toward making clean post-mission orbital disposal a practical option for many satellite operators. Through this demonstration, BULL will verify the performance of 'HORN' under real operational conditions and aims to become a certified supplier for EnduroSat missions requiring orbital disposal solutions (PMD functionality).

※1: 16U Size: A standard for small satellites (CubeSats), referring to a satellite composed of sixteen 10cm × 10cm × 10cm cubes (1U units).

※2: In-orbit demonstration: Launching a developed device into actual space (orbit) to verify its operation and functionality under real space conditions.

※3: Transporter-22: A recurring small satellite rideshare launch mission offered by U.S.-based SpaceX. It is operated using the company's primary rocket, the Falcon 9.

Photo: Raycho Raychev, Founder & CEO of EnduroSat (left), and Kyoshi Uto, Representative Director, Founder & CEO of BULL Inc. (right)

The Need for Practical Solutions to Prevent Spacecraft from Becoming Orbital Debris After Mission Completion

Currently, the number of objects launched into orbit exceeds the number being removed, and many of these objects remain in orbit for extended periods. As a result, satellite operators, launch service providers, and space agencies increasingly demand reliable, lightweight methods to deorbit spacecraft after mission completion. 'HORN' addresses this need by using a deployable membrane to increase atmospheric drag, thereby shortening the time a satellite remains in orbit after its mission ends. As a passive system requiring no propellant, it enables rapid orbital disposal without the drawbacks associated with active propulsion systems—such as increased mass, cost, and failure risk.

Performance of 'HORN' to Be Validated in Space

Under this agreement, 'HORN' will be integrated into EnduroSat's 16U satellite and undergo in-orbit demonstration in 2027. This will allow performance validation under actual thermal, vacuum, and operational conditions that cannot be fully replicated in ground testing environments. Demonstrating the technology on a satellite from EnduroSat, which has over 100 satellite operations under its belt, will help establish the reliability required by satellite operators and regulatory authorities when selecting deorbiting methods. For BULL, this initiative will expand the application scope of 'HORN' from previous collaborations with launch vehicle providers like Ariane 6 and Vega C to artificial satellites—the primary future source of space debris.

A Reliable Option for Satellite Operators

Upon successful demonstration, 'HORN' will become a flight-proven option within EnduroSat's supply chain. By joining EnduroSat's trusted supplier list, BULL will enable satellite operators to select a verified passive deorbiting solution (PMD method). The two companies will continue collaborating after this mission, leveraging feedback on EnduroSat's platform and integration to develop and improve next-generation 'HORN' devices with higher compatibility. This will open the path to faster, lower-risk compliance with orbital disposal regulations across different jurisdictions.

Executive Comments

Kyoshi Uto, Representative Director, Founder & CEO, BULL Inc.

"The majority of future space debris will originate from satellites launched into orbit without reliable means of deorbiting. 'HORN' is our solution to this challenge. By using a passive, membrane-deployment structure that requires no propellant, 'HORN' enables spacecraft to deorbit after mission completion. Conducting an in-orbit demonstration using an EnduroSat satellite under real operational conditions is an extremely important milestone. It will prove that 'HORN' can deploy as designed and achieve orbital disposal in the orbital regions where debris is generated. This demonstration will transform appropriate post-mission disposal from an idealistic 'goal' into a practical 'option' that operators can choose."

Raycho Raychev, Founder & CEO, EnduroSat

"We are proud to support BULL's innovation toward sustainable orbital operations. By flying HORN, BULL's team will be able to demonstrate to future customers a passive and lightweight deorbiting capability."

About BULL Inc.

BULL is a startup with the vision of making interplanetary travel 'ordinary.' The company aims to provide affordable and simple space utilization services by leveraging re-entry technologies. Based in Utsunomiya City, Tochigi Prefecture, BULL promotes industry-academia-government collaboration. The company develops devices to prevent space debris generation and microgravity experimental satellites and equipment for orbital utilization, contributing to SDGs in the new era of space development.

Photo: 3rd Anniversary Commemorative Photo (at BULL's Hiraide Base)

Company Name: BULL Inc. (Bull)

Headquarters: 43-103 Hiraide Industrial Park, Utsunomiya City, Tochigi Prefecture

Representative: Representative Director / CEO Kyoshi Uto

Founded: November 2022

Business Activities: Space debris mitigation, orbital utilization-related services

Website: https://bull-space.com/

※The company's headquarters address was changed effective June 1, 2026. The new address is '43-103 Hiraide Industrial Park, Utsunomiya City, Tochigi Prefecture'.

About EnduroSat

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