A removal mission is only defensible if the target earns it. These are the six gates we screen a candidate against before any architecture work begins — the same filter that separates a fundable ADR mission from an expensive demonstration.
Mass and cross-sectional area drive how much future debris a target would generate if it fragments. Large abandoned upper stages in congested shells dominate the risk integral — a 1 kg CubeSat and a 1.8 t stage are not the same problem.
Below roughly 500 km drag does the work for free within a few years. Above it, natural decay stops being a strategy. The 700–900 km band is where objects persist for centuries and where removal actually buys something.
Tumble rate sets the capture concept. A near-inertial target admits a simple rigid capture; anything beyond a few degrees per second forces detumble first, which is where electromagnetic and contactless methods earn their place.
Legacy hardware was not designed to be caught. Launch adapter rings and nozzle throats are the usual features of opportunity. Absence of a cooperative fixture is the single biggest driver of mechanism complexity and qualification cost.
Plane changes are punishing. Targets sharing RAAN and inclination can be chained in one mission; anything requiring significant plane change usually collapses the business case before the propulsion sizing is even finished.
Under the Outer Space Treaty and the Liability Convention, an object remains the property of its launching state indefinitely. Removal requires consent. The legal path is often longer than the engineering one and belongs in the schedule from day one.
Post-mission disposal expectations have tightened sharply — ESA’s Space Debris Mitigation Policy and the FCC’s rule both moved from the legacy 25-year guideline toward a 5-year horizon, and ESA’s Zero Debris Charter targets debris-neutral operations by 2030. Compliance is becoming a design requirement rather than a reporting exercise.
0G Systems is a specialist space engineering firm based in the Netherlands, focused on making the orbital environment safer and more sustainable.
Our primary work centres on Active Debris Removal — engineering the capture mechanisms, de-orbit strategies, and proximity operations needed to remove derelict objects from crowded orbital shells.
Our secondary focus is In-Space Servicing: electromagnetic docking concepts, on-orbit inspection, refuelling architectures, and cooperative proximity operations that extend satellite lifetimes and reduce replacement demand.
Mission architecture, capture mechanism design, and de-orbit planning for uncooperative targets. Our core commercial and research focus.
Electromagnetic docking, contactless CubeSat capture, on-orbit inspection, and refuelling mission concepts.
Requirements management, trade studies, ICD, FMEA, and V&V planning tailored to NewSpace timelines and ECSS standards.
Monopropellant, bipropellant, and cold-gas thruster design from concept through hot-fire qualification.
High-fidelity CFD for internal flows, plume impingement, thermal management, and propellant feed systems.
Solenoid, latch, and proportional valves. Lifecycle testing, leakage characterization, and flight-heritage documentation.
ECSS-E-ST-10 (system engineering), ECSS-Q-ST-30 (dependability), ECSS-E-ST-35 (propulsion), ISO 24113 and IADC guidelines for debris mitigation.
Design Definition File, Design Justification File, FMEA/FMECA worksheets, Verification Control Document, requirement flow-down matrices, and trade-study reports.
Short feasibility studies, subsystem design packages, independent review support ahead of PDR/CDR, or embedded support through a qualification campaign.
Representative studies and analyses. Figures below are study outputs and design targets, not qualified flight results — where work was performed under a prior employer or NDA, the client is not named.
1N-class green monopropellant thruster for LEO constellation. PDR to qual in 14 months.
CFD-driven manifold redesign and latch valve qualification. 35% ΔP reduction.
Analytical and 6-DOF simulation study of electromagnetic capture for derelict CubeSats. Force budget closes at 2 m standoff in simulation; no hardware demonstration to date.
Propulsion, qualification, or ADR mission architecture — let's talk.
info@0gpropulsionsystems.comScroll down to scrub the simulation above in real time.
The servicer holds the V-bar corridor at 10 m. The coil array raises a dipole moment and the resulting Lorentz attraction is millinewton-scale — far too weak to close the gap on its own, so GNC does the translating and the field does the sensing. Closing velocity is held below 5 cm/s.
Dipole strength scales as 1/r³, so the last two metres are where the physics starts working for you. Eddy currents induced in the target’s conductive structure oppose relative motion and bleed off tumble rate passively. Field orientation is steered to converge relative attitude inside 2°.
Attraction peaks at newton scale. The control law switches to proximity-hold, trading coil current against closing rate to land contact velocity under 1 cm/s. The two vehicles are electromagnetically coupled with no mechanical latching and no impact transient.
A low standby current maintains the lock. From here the servicer can rigidise with mechanical latches if the mission needs load path, or proceed on the EM bond alone for inspection, refuelling, or a controlled de-orbit burn.