A multi-tenant orbital industrial park for debris recycling and in-space manufacturing.

Why 800km?

Driven by feedstock availability and permanence. This altitude coincides with the approximate peak in LEO debris population (Hayashi et al., 2025), and is where the most valuable targets sit, being rocket bodies most critical for removal in a cluster between 750 and 1000km (Anselmo & Pardini, 2016).

Unlike 400km, where atmospheric drag pulls debris downward and constituent masses grow tenfold to 2050, the 800km population remains stable across 2016–2050 (Hayashi et al., 2025).

Novelty in ARACHNEA’s approach

Architecturally, ARACHNEA is conceived as an orbital industrial park. Its form follows the path of the material: debris enters at the capture end, and is sorted, melted, and manufactured back into structure as it travels the central spine. Habitation is present to service and monitor the process rather than to be ARACHNEA’s purpose.

The multi-tenant approach is expressed directly in the built form. The station is partitioned into branches that separate operators lease and feed with their own catcher craft, all delivering into a shared material pool. Circulation between facilities is handled by a contactless electromagnetic carrier, the Glider module, using the primary structure as a path with no wheels or friction.

The station is designed to grow by self-similar repetition of its clusters along the spine, ultimately building its own extensions from the feedstock it produces, closing the loop between what it recycles and what it becomes.

ARACHNEA’s contribution is not the recycling of orbital debris, which is a concept which is already well established from Matas’s ORDER station (2020). What is new is the economic architecture built around it. ARACHNEA’s approach reframes debris from waste-to-dispose or metal-to-sell into a shared orbital material stock, and constructs a two-product financial mechanism that makes both the manufacturing and the remediation independently bankable.

• Glider module — a contact-free carrier riding the main truss, moving crew between facilities; its cupola serves supervision and maintenance
• Habitation — an inflatable housing twelve crew members on three-month rotations, built around shared spaces and plant growth

Orbital debris comes in different sizes, thus the intake system treats small fragments and large intact objects differently (Matas, 2020; Leonard & Williams, 2023). Fragments are sorted before processing, while rocket bodies are handled in a separate Heavy Intake Bay (Leonard & Williams, 2023). This makes the system better suited to the material’s size, condition, and predictability (Anselmo & Pardini, 2016).

The Heavy Intake Bay is sized at 6.8m diameter and 14m length, matching the SpaceX Starship payload envelope, but also accommodating the largest and most important LEO rocket bodies identified by Anselmo & Pardini (2016), while leaving room for robotic clearance, manipulators, clamps, and electronics.

Incoming stages are held in place by adjustable pneumatic clamps, while two radial manipulator arms, each fitted with XRF probes, identify materials directly at the contact point, while preloaded dissection sequences guide the process using stage manifests from operators.

Sorted debris is melted into feedstock using electromagnetic levitation melting, a contactless method based on the ESA/DLR levitation furnace flown on the ISS since 2015 (Schroeder et al., 2023). Alternating-current coils induce eddy currents in the conductive sample, which simultaneously heat it through ohmic losses and hold it in position by the Lorentz Force so the molten metal never contacts a crucible.

EML favours highly conductive, non-ferromagnetic metals such as aluminium and copper; ferromagnetic materials such as iron are harder to process, as they strongly interact with the coils. This spread of melting points and conductivities is why incoming debris must first be sorted by composition (Schroeder et al., 2023). The process is itself modest in power: 1kW can melt about 100g of Al (s) in roughly 200 seconds, which makes it compatible with solar power (Schroeder et al., 2023).

In microgravity, the melt becomes more microstructurally uniform because of the absence of convection or sedimentation. The main thermal challenge is that in vacuum, leaving thermal radiation as the only route to reject the melt’s heat — the reason for the facility’s dedicated radiator provision.

Electron beam additive manufacturing

Sorted feedstock is drawn into wire and built by Electron Beam Additive Manufacturing (EBAM), a freeform process demonstrated by NASA as EBF³ (Hafley et al., 2009).

The process fits an orbital station naturally: wire is safer to handle than powder in microgravity, the electron beam couples efficiently with reflective metals (i.e. aluminium), and the vacuum it depends on is offered by the environment.

Two limitations are managed by design. Surface tension governs the molten pool, so wire-to-substrate distance is held precisely. Furthermore, a vacuum melt pool can lose volatile alloying elements through preferential vaporisation (Hafley et al., 2009; O’Donnell et al., 2023), countered by tuning beam parameters and verifying feedstock composition before deposition.