Physical demonstrator built and tested

Momentum,
delivered externally.

Project COELI investigates a controlled stream of electromagnetically accelerated pellets that transfers momentum progressively to a separate receiver.

Watch prototype video Explore the technology

7: electromagnetic stages
8–9 m/s: measured pellet speed
~15 Hz: typical test cadence

Prototype evidenceVideo

Watch prototype video on YouTube

Evidence is labelled throughout this site:

Demonstrated Measured Simulated Proposed Target

Technical presentation

Explore the programme

01ConceptExternal momentum transfer 02Prototype & resultsPhysical evidence 03AcceleratorSeven-stage architecture 04Stability & trackingKeeping the stream centred 05SimulationDynamics and sensitivity 06Technical challengesWhat remains unresolved 07Gate ANext experimental phase 08ApplicationsEarth to Solar System

Concept

A sequence of small impulses becomes a controllable average force.

The accelerator, power electronics and energy source remain in a fixed installation. Pellets leave the accelerator as a directed stream and impact a separate catcher. Mass, speed and cadence regulate the momentum delivered over time.

01Fixed infrastructureEnergy · control · accelerator

02Pellet streamMass · speed · cadence

03ReceiverCumulative momentum transfer

Demonstrated principle

Average force ≈ cadence × impulse per impact

Unlike a single-shot launcher, COELI studies progressive momentum delivery while the receiver is already in motion.

The seven-stage Project COELI laboratory demonstrator with its control computer, electronics and receiver

Physical hardwareFounder-built laboratory demonstrator

Hardware exists

Existing prototype

One machine closes the complete experimental chain.

The demonstrator integrates projectile injection, seven electromagnetic stages, power electronics, optical sensing, C/C++ control on Arduino, speed measurement, repeated impacts and a lightweight catcher.

~4.5 s Best clean levitation sequence reported in the SPRIND application.

Current measurements were generated by the founder. Professional metrology and independent validation are explicit objectives of the next phase.

Experimental results

Small-scale evidence, reported without extrapolation.

The current rig verifies the operating chain at laboratory scale. It does not yet validate long-range collimation or high-speed operation.

Measured8–9 m/s

Pellet speed in current prototype tests.

Measured~15 Hz

Typical cadence with approximately 3 g steel pellets.

Demonstrated3–5 s

Reported hovering episodes; best clean sequence approximately 4.5 s.

Measured20 Hz

Stable injector cadence when evaluated separately.

Physically demonstrated

Projectile feeding and injection
Seven-stage electromagnetic acceleration
Optical detection and speed measurement
Repeated impacts and brief levitation

Simulated / explored

Rigid-body translation and rotation
Off-centre impacts and catcher stability
Atmosphere, drag and timing sensitivity
Candidate wake and tracking strategies

Not yet demonstrated

~100 m/s professional bench
100 Hz injection in short bursts
Long-range stream collimation
Flight-scale momentum transfer

Electromagnetic accelerator

Sequential stages add velocity while sensors preserve timing traceability.

The prototype uses seven electromagnetic stages. Optical sensors detect pellet passage, the control system coordinates coil firing, and measured events allow the timing chain to be reconstructed.

01
Inject
One pellet enters with controlled timing and position.
02
Detect
Optical barriers establish its actual passage rather than relying only on fixed delays.
03
Accelerate
Coils are fired sequentially as the pellet moves through the vertical launcher.
04
Measure
Speed and event timing are recorded before the pellet joins the stream.

The physical pellet injector used in the Project COELI prototype — Prototype injector. This is an experimental implementation, not a final design.

Pellet stream & momentum transfer

The stream is a controllable sequence of discrete masses—not a continuous jet.

Each pellet transfers a small impulse. Repetition converts those impulses into an average force whose principal control variables are mass, speed and cadence.

Pellet mass

Changes the momentum available per projectile and can be varied through projectile families or length.

Relative impact speed

Governs delivered impulse and catcher loading. It is distinct from launcher-frame pellet speed.

Cadence

Sets how frequently the receiver encounters discrete impulses and therefore helps regulate average force.

Control principle

Launcher speed must adapt as the receiver accelerates.

The emitted cadence and the cadence encountered by a moving receiver do not remain identical. Future control must adapt launch timing and pellet speed while limiting relative impact speed to the receiver’s structural envelope.

Project COELI adaptive-mission simulation with active receiver tracking enabled

Simulation outputActive tracking enabled

Stability & stream tracking

Aiming points the emitter. Tracking follows the stream that actually arrives.

COELI separates initial pointing from the receiver’s ability to estimate the statistical axis of the impact pattern and correct its position to remain centred.

Explored physically

Passive geometry

Receiver shape and geometric elements have been tested at prototype scale.

Simulated

Rotational stability

Off-centre impacts, torques, centre of gravity and gyroscopic strategies are represented in 3D.

Proposed

Active tracking

Future sensors and control would estimate the moving stream axis and command recentering.

Simulation

A test-selection tool—not a substitute for experimental validation.

The model helps interpret observed motion, compare stabilization strategies and identify which parameters need to be measured next.

Project COELI three-dimensional catcher dynamics simulator showing the receiver and its control parameters — 3D rigid-body simulatorTranslation · rotation · impacts · dispersion · stabilization

Model includes

Gravity and receiver translation
Rotation and off-centre impact torques
Restitution and tangential friction
Parameterized dispersion and atmosphere
Approximate collisions and adaptive timing

Needs measured inputs

Actual dispersion distributions
Impact geometry and restitution
Catcher vibration and deformation
Thermal distribution and wear
Wind, yaw, ablation and fragmentation

View documented simulation sensitivities +

Sensitivity—not flight prediction

A corrected longitudinal study used a 27 kg system, a 1 m catcher, 20 g projectiles, 100 Hz source cadence, a 2 km/s launch-speed ceiling and a 150 m/s relative-impact limit. It calculated 34.28 km apogee for one specified aerodynamic case and 79.65 km for an optimized case. Aerodynamics dominated after stability was controlled.

A separate reduced wake model evaluated lateral concentration at 200 m/s and 100 Hz. At 500 m it produced 60.00%, 14.47% and 3.11% reductions in standard dispersion for three assumed decay laws. The normalization is exploratory and must be measured; the result is neither CFD nor evidence of drag reduction.

Current technical challenges

The programme is defined by the uncertainties it must measure.

Two immediate scaling questions dominate: repeatable speed at useful cadence, and angular concentration as distance grows.

Speed × cadence

Increase pellet speed without losing timing control, efficiency, reliability or sustained operation.

Immediate

Dispersion × collimation

Measure how the stream widens and determine whether injection, geometry, correction and tracking can reduce it.

Immediate

Thermal and electrical behaviour

Characterize switching, voltage drop, coil temperature, local banks, wear and safe discharge.

Gate A

Receiver response

Measure impulse, rebound, vibration, stability, heating, erosion and the effect of off-centre impacts.

Gate A+

Atmospheric scaling

Drag, attitude stability, ablation, fragmentation and high-Mach heating become increasingly important later.

Later

Gate A · next experimental phase

Current target

~100m/s

A professional, modular and instrumented test bench.

The current reduced Phase A plan makes approximately 100 m/s the required milestone, with 200 m/s retained as a stretch target. It preserves the experiments needed to decide whether COELI should scale.

Target

100 Hz injector

Centred, timed and measured short bursts, initially dry or at low energy.

Target

~100 m/s bench

Safe, repeatable operation with a platform designed for later expansion.

Characterize

Operating envelope

Velocity, cadence, efficiency, angular dispersion and thermal behaviour.

Characterize

Momentum transfer

Impulse, rebound, vibration, receiver stability, heating and wear.

Why 100 m/s is a useful gate

For the 5 g reference pellet, 100 m/s corresponds to 25 J of mechanical energy per pellet. At 100 Hz that is 2.5 kW mechanical during a burst; the reduced plan estimates approximately 25 kW electrical at 10% efficiency or 36 kW at 7%. This regime is high enough to force professional decisions on pulsed power, sensing, heat, repeatability and containment, while keeping a modular route toward 200 m/s and later 500–1,000 m/s.

Roadmap update

The final SPRIND master application dated 27 August 2026 described ~200 m/s as the Phase A reference. A later reduced-scope plan dated 28 August 2026 changed the mandatory milestone to ~100 m/s and retained 200 m/s as a stretch target. This site follows the later plan.

Potential applications

A staged research path from test platforms to space transport.

Applications are candidates, not demonstrated services. Each requires its own validation campaign and operating envelope.

Near term

Experimental momentum-transfer platforms

Instrumented research into repeated impacts, external force delivery, receivers and high-cadence mass acceleration.

Early application

Upper-atmosphere access & sampling

Potential controlled access to the 50–90 km region for compact instruments, subject to aerodynamic, safety and recovery validation.

Development path

Launch assistance

External momentum could supplement other launch architectures before stand-alone orbital performance is reached.

Longer term

Orbital and in-space transport

Proposed infrastructure for progressive momentum delivery to orbital or interplanetary receivers.

Long horizon

Solar System applications

Potential transport architectures within the Solar System, evaluated only after terrestrial and orbital scaling is demonstrated.

Intellectual property

Four Spanish utility-model applications are under examination.

The portfolio covers specific implementations and subsystems. Filing is not the same as grant, validation or freedom to operate.

Application	Filed	Scope described in the SPRIND submission	Status
U202630900	29 Apr 2026	Cableless space elevator: continuous or quasi-continuous momentum transfer and stability	Under examination
U202630938	04 May 2026	Distributed electromagnetic collimation of discrete-mass streams	Under examination
U202630967	08 May 2026	Modular electromagnetic launcher for progressive pellet-stream momentum transfer	Under examination
U202630968	08 May 2026	Transitional aerodynamic channel generated by sequential discrete masses	Under examination

Founder / team

Rafael Mario Sosa Brito

Founder · Technical Director

Astrophysicist and software engineer. He conceived the architecture, self-financed and built the demonstrator, developed its control software and 3D simulator, and carried out the preliminary measurements.

Next specialist capabilities

High-cadence mechatronics
Pulsed power and local control
Professional metrology
Experimental safety
Aerodynamics and materials

Contact

Continue the technical conversation.

Project COELI
Rafael Mario Sosa Brito
Founder / Technical Director

CONTACT_EMAIL_TO_BE_ADDED

Momentum,delivered externally.