PROX-M18

Space Waste Technologies — Product Datasheet

PROX-M18

Proximity Operations eXecutor · Model 18

Rendezvous, Proximity Operations, Docking & Undocking Platform

RPODUTRL 3–46-DOF NavNon-CooperativeDual-Use
<3 kg
Target Mass
22 W
Nominal Power
200 m
Autonomous Range
10 Hz
Nav Update Rate
28 V
Bus Voltage
00Operational Environment

On-orbit imagery · NASA public domain · Randomised on each visit

Images: NASA Image & Video Library — Public Domain

01Sensor Suite
PROX-M18 sensor configuration schematic
PROX-M18 · Sensor Configuration · Rev A
Sensor Qty Performance Parameters
LiDARTime-of-Flight 1
  • Range: 0.3 – 200 m
  • Range accuracy: ±3 cm (<50 m) / ±0.1% (>50 m)
  • Angular resolution: 0.1°
  • FOV: 25° × 25°
  • Update rate: 10 Hz
  • Wavelength: 905 nm
Stereo VisionCMOS, matched pair 2
  • Resolution: 2 MP per sensor
  • Pixel pitch: 3.45 μm
  • Focal length: 12 mm
  • FOV: 52° × 40°
  • Frame rate: 30 fps
  • Baseline: 80 mm
Wide-FOV CameraAcquisition & tracking 1
  • Resolution: 4 MP
  • FOV: 120° × 90°
  • Frame rate: 15 fps
  • Function: initial target acquisition & far-field tracking
IMU6-DOF inertial 1
  • Gyro bias stability: <0.1°/h
  • Accel noise density: <80 μg/√Hz
  • Angular rate range: ±450°/s
  • Bandwidth: 400 Hz
  • Axes: 3-axis gyro + 3-axis accel
IR IlluminatorNear-IR LED array 1
  • Wavelength: 850 nm
  • Pattern: retroreflector-compatible
  • Function: docking target illumination in eclipse
02Navigation Performance
Relative Position
Accuracy (<10 m)±3 cm
Accuracy (10–200 m)±0.5% range
Relative velocity±2 mm/s
Max acquisition range200 m
Attitude & Closure
Relative attitude accuracy±0.3°3σ, <20 m
Terminal closure speed<0.1 m/ssoft-capture
Max target tumble rate5°/s
Nav solution update rate10 Hz
Processing
ProcessorARM Cortex-A53quad-core
AI inference latency<40 ms
Memory4 GB LPDDR4
Storage32 GB eMMC
Electrical & Mechanical
Bus voltage28 Vunregulated
Power (nominal / peak)22 W / 40 W
InterfacesSpW · CAN · RS-422
Operating temperature-40 to +85°C
03Flight Heritage — DARPA Orbital Express

The PROX-M18 architecture is designed against the hard-won lessons of DARPA Orbital Express (2007) — the first autonomous US satellite-to-satellite rendezvous, capture, and servicing demonstration. ASTRO and NextSat, launched together into a 492 km orbit, proved autonomous docking, hydrazine transfer, and component swaps were possible. They also proved how it goes wrong: during unmated Scenario 3-1, a sensor-computer failure and a feedback loop between sensor software and the navigation filter nearly stranded the chaser — optical glints were ingested as valid target tracks, biasing the state estimate while shrinking its uncertainty. NASA's NESC review of those anomalies is foundational reading for this product, and each major lesson maps to a PROX-M18 design decision.

OE Lesson Learned (NESC) LL PROX-M18 Design Response
Navigation must never be taken for granted 1 Independent navigation-state health monitor with dissimilar cross-checks; loss-of-nav triggers a passively safe abort trajectory, not a hold.
IR sensing adds robustness to unanticipated lighting 2 850 nm IR illumination and eclipse-rated tracking are primary-path capabilities in the sensor suite — not supplemental — because IR is what recovered OE.
Tightly coupled sensor and nav software mutually reinforce failures 3 Decoupled estimation architecture: the filter screens optical artifacts (glints, glares, hot pixels) without feeding biased target ephemerides back into sensor target selection.
Calibrate on-orbit with the target out of frame and bright sources in frame 4 Built-in calibration mode images the Earth limb and Moon with the target excluded from the field of view before any unmated operation.
Continuous situational-awareness imagery is critical to abort recovery 5 Low-rate SA video downlink over relay is a baseline system capability, sized for continuous coverage — not a contingency reconfiguration.
The filter must identify and screen erroneous sensor data 6 Measurement gating with innovation-based rejection and bounded covariance collapse; no single sensor can monopolize the state estimate.

REFERENCES · NASA/TM-2011-217088 · NESC-RP-10-00628 — “RPODU Lessons Learned from the DARPA Orbital Express Demonstration” (Dennehy & Carpenter, 2011) · “Technology Development of AR&D Sensors and Docking Mechanism for the Asteroid Redirect Crewed Mission” (Hinkel et al., NASA JSC/GSFC)

04Compliance & Standards
ECSS-E-ST-10-04CMIL-STD-1553 CompatibleITAR 22 CFR Part 121CMMC Level 2 RoadmapEAR99 Commercial TrackSpaceWire ECSS-E-ST-50-12C

Integrate PROX-M18 Into Your Mission

Partnership inquiries · Government & defense · Custom interface requirements